[PATCH] KVM: Add wrapper script around QEMU to test kernels

[PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
would be doing and what he expects from it. Basically he wants a
small and simple tool he and other developers can run to try out and
see if the kernel they just built actually works.

Fortunately, QEMU can do that today already! The only piece that was
missing was the "simple" piece of the equation, so here is a script
that wraps around QEMU and executes a kernel you just built.

If you do have KVM around and are not cross-compiling, it will use
KVM. But if you don't, you can still fall back to emulation mode and
at least check if your kernel still does what you expect. I only
implemented support for s390x and ppc there, but it's easily extensible
to more platforms, as QEMU can emulate (and virtualize) pretty much
any platform out there.

If you don't have qemu installed, please do so before using this script. Your
distro should provide a package for it (might even call it "kvm"). If not,
just compile it from source - it's not hard!

To quickly get going, just execute the following as user:

    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash

This will drop you into a shell on your rootfs.

Happy hacking!

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - fix naming of QEMU
  - use grep -q for has_config
  - support multiple -a args
  - spawn gdb on execution
  - pass through qemu options
  - dont use qemu-system-x86_64 on i386
  - add funny sentence to startup text
  - more helpful error messages
---
 scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 334 insertions(+), 0 deletions(-)
 create mode 100755 scripts/run-qemu.sh

diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
new file mode 100755
index 0000000..5d4e185
--- /dev/null
+++ b/scripts/run-qemu.sh
@@ -0,0 +1,334 @@
+#!/bin/bash
+#
+# QEMU Launcher
+#
+# This script enables simple use of the KVM and QEMU tool stack for
+# easy kernel testing. It allows to pass either a host directory to
+# the guest or a disk image. Example usage:
+#
+# Run the host root fs inside a VM:
+#
+# $ ./scripts/run-qemu.sh -r /
+#
+# Run the same with SDL:
+#
+# $ ./scripts/run-qemu.sh -r / --sdl
+# 
+# Or with a PPC build:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r /
+# 
+# PPC with a mac99 model by passing options to QEMU:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+#
+
+USE_SDL=
+USE_VNC=
+USE_GDB=1
+KERNEL_BIN=arch/x86/boot/bzImage
+MON_STDIO=
+KERNEL_APPEND2=
+SERIAL=ttyS0
+SERIAL_KCONFIG=SERIAL_8250
+BASENAME=$(basename "$0")
+
+function usage() {
+	echo "
+$BASENAME allows you to execute a virtual machine with the Linux kernel
+that you just built. To only execute a simple VM, you can just run it
+on your root fs with \"-r / -a init=/bin/bash\"
+
+	-a, --append parameters
+		Append the given parameters to the kernel command line.
+
+	-d, --disk image
+		Add the image file as disk into the VM.
+
+	-D, --no-gdb
+		Don't run an xterm with gdb attached to the guest.
+
+	-r, --root directory
+		Use the specified directory as root directory inside the guest.
+
+	-s, --sdl
+		Enable SDL graphical output.
+
+	-S, --smp cpus
+		Set number of virtual CPUs.
+
+	-v, --vnc
+		Enable VNC graphical output.
+
+Examples:
+
+	Run the host root fs inside a VM:
+	$ ./scripts/run-qemu.sh -r /
+
+	Run the same with SDL:
+	$ ./scripts/run-qemu.sh -r / --sdl
+	
+	Or with a PPC build:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r /
+	
+	PPC with a mac99 model by passing options to QEMU:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+"
+}
+
+function require_config() {
+	if [ "$(grep CONFIG_$1=y .config)" ]; then
+		return
+	fi
+
+	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
+	exit 1
+}
+
+function has_config() {
+	grep -q "CONFIG_$1=y" .config
+}
+
+function drive_if() {
+	if has_config VIRTIO_BLK; then
+		echo virtio
+	elif has_config ATA_PIIX; then
+		echo ide
+	else
+		echo "\
+Your kernel must have either VIRTIO_BLK or ATA_PIIX
+enabled for block device assignment" >&2
+		exit 1
+	fi
+}
+
+GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
+	-n "$(basename \"$0\")" -- "$@"`
+
+if [ $? != 0 ]; then
+	echo "Terminating..." >&2
+	exit 1
+fi
+
+eval set -- "$GETOPT"
+
+while true; do
+	case "$1" in
+	-a|--append)
+		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
+		shift
+		;;
+	-d|--disk)
+		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
+			file=$2,if=$(drive_if),cache=unsafe"
+		USE_DISK=1
+		shift
+		;;
+	-D|--no-gdb)
+		USE_GDB=
+		;;
+	-h|--help)
+		usage
+		exit 0
+		;;
+	-r|--root)
+		ROOTFS="$2"
+		shift
+		;;
+	-s|--sdl)
+		USE_SDL=1
+		;;
+	-S|--smp)
+		SMP="$2"
+		shift
+		;;
+	-v|--vnc)
+		USE_VNC=1
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		echo "Could not parse option: $1" >&2
+		exit 1
+		;;
+	esac
+	shift
+done
+
+if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
+	echo "\
+Error: Please specify at least -r or -d with a target \
+FS to run off of" >&2
+	exit 1
+fi
+
+# Try to find the KVM accelerated QEMU binary
+
+[ "$ARCH" ] || ARCH=$(uname -m)
+case $ARCH in
+x86_64)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	# QEMU's own build system calls it qemu-system-x86_64
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
+	;;
+i*86)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# i386 version of QEMU
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
+	;;
+s390*)
+	KERNEL_BIN=arch/s390/boot/image
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
+	;;
+ppc*)
+	KERNEL_BIN=vmlinux
+
+	IS_64BIT=
+	has_config PPC64 && IS_64BIT=64
+	if has_config PPC_85xx; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
+	elif has_config PPC_PSERIES; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
+		SERIAL=hvc0
+		SERIAL_KCONFIG=HVC_CONSOLE
+	elif has_config PPC_PMAC; then
+		has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
+		SERIAL_KCONFIG=SERIAL_PMACZILOG
+	else
+		echo "Unknown PPC board" >&2
+		exit 1
+	fi
+
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
+	;;
+esac
+
+if [ ! -e "$QEMU_BIN" ]; then
+	echo "\
+Could not find a usable QEMU binary. Please install one from \
+your distro or from source code using:
+
+  $ git clone git://git.qemu.org/qemu.git
+  $ cd qemu
+  $ ./configure
+  $ make -j
+  $ sudo make install
+" >&2
+	exit 1
+fi
+
+# The binaries without kvm in their name can be too old to support KVM, so
+# check for that before the user gets confused
+if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
+     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
+	echo "Your QEMU binary is too old, please update to at least 0.15." >&2
+	exit 1
+fi
+QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
+
+# We need to check some .config variables to make sure we actually work
+# on the respective kernel.
+if [ ! -e .config ]; then
+	echo "\
+Please run this script on a fully compiled and configured
+Linux kernel build directory" >&2
+	exit 1
+fi
+
+if [ ! -e "$KERNEL_BIN" ]; then
+	echo "Could not find kernel binary: $KERNEL_BIN" >&2
+	exit 1
+fi
+
+QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
+
+if [ "$USE_SDL" ]; then
+	# SDL is the default, so nothing to do
+	:
+elif [ "$USE_VNC" ]; then
+	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
+else
+	# When emulating a serial console, tell the kernel to use it as well
+	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
+	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
+	MON_STDIO=1
+	require_config "$SERIAL_KCONFIG"
+fi
+
+if [ "$ROOTFS" ]; then
+	# Using rootfs with 9p
+	require_config "NET_9P_VIRTIO"
+	KERNEL_APPEND="$KERNEL_APPEND \
+root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
+
+#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
+
+
+	QEMU_OPTIONS="$QEMU_OPTIONS \
+-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
+-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
+fi
+
+[ "$SMP" ] || SMP=1
+
+# User append args come last
+KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
+
+############### Execution #################
+
+QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
+
+echo "
+	################# Linux QEMU launcher #################
+
+This script executes your currently built Linux kernel using QEMU. If KVM is
+available, it will also use KVM for fast virtualization of your guest.
+
+The intent is to make it very easy to run your kernel. If you need to do more
+advanced things, such as passing through real devices, please use QEMU command
+line options and add them to the $BASENAME command line using --.
+
+This tool is for simplicity, not world dominating functionality coverage.
+(just a hobby, won't be big and professional like libvirt)
+
+"
+
+if [ "$MON_STDIO" ]; then
+	echo "\
+### Your guest is bound to the current foreground shell. To quit the guest, ###
+### please use Ctrl-A x                                                     ###
+"
+fi
+
+echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""
+echo
+
+GDB_PID=
+if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
+	# Run a gdb console in parallel to the kernel
+
+	# XXX find out if port is in use
+	PORT=$$
+	xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
+	GDB_PID=$!
+	QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
+fi
+
+$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
+wait $GDB_PID &>/dev/null
+
-- 
1.6.0.2

[PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
would be doing and what he expects from it. Basically he wants a
small and simple tool he and other developers can run to try out and
see if the kernel they just built actually works.

Fortunately, QEMU can do that today already! The only piece that was
missing was the "simple" piece of the equation, so here is a script
that wraps around QEMU and executes a kernel you just built.

If you do have KVM around and are not cross-compiling, it will use
KVM. But if you don't, you can still fall back to emulation mode and
at least check if your kernel still does what you expect. I only
implemented support for s390x and ppc there, but it's easily extensible
to more platforms, as QEMU can emulate (and virtualize) pretty much
any platform out there.

If you don't have qemu installed, please do so before using this script. Your
distro should provide a package for it (might even call it "kvm"). If not,
just compile it from source - it's not hard!

To quickly get going, just execute the following as user:

    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash

This will drop you into a shell on your rootfs.

Happy hacking!

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - fix naming of QEMU
  - use grep -q for has_config
  - support multiple -a args
  - spawn gdb on execution
  - pass through qemu options
  - dont use qemu-system-x86_64 on i386
  - add funny sentence to startup text
  - more helpful error messages
---
 scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 334 insertions(+), 0 deletions(-)
 create mode 100755 scripts/run-qemu.sh

diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
new file mode 100755
index 0000000..5d4e185
--- /dev/null
+++ b/scripts/run-qemu.sh
@@ -0,0 +1,334 @@
+#!/bin/bash
+#
+# QEMU Launcher
+#
+# This script enables simple use of the KVM and QEMU tool stack for
+# easy kernel testing. It allows to pass either a host directory to
+# the guest or a disk image. Example usage:
+#
+# Run the host root fs inside a VM:
+#
+# $ ./scripts/run-qemu.sh -r /
+#
+# Run the same with SDL:
+#
+# $ ./scripts/run-qemu.sh -r / --sdl
+# 
+# Or with a PPC build:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r /
+# 
+# PPC with a mac99 model by passing options to QEMU:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+#
+
+USE_SDL=
+USE_VNC=
+USE_GDB=1
+KERNEL_BIN=arch/x86/boot/bzImage
+MON_STDIO=
+KERNEL_APPEND2=
+SERIAL=ttyS0
+SERIAL_KCONFIG=SERIAL_8250
+BASENAME=$(basename "$0")
+
+function usage() {
+	echo "
+$BASENAME allows you to execute a virtual machine with the Linux kernel
+that you just built. To only execute a simple VM, you can just run it
+on your root fs with \"-r / -a init=/bin/bash\"
+
+	-a, --append parameters
+		Append the given parameters to the kernel command line.
+
+	-d, --disk image
+		Add the image file as disk into the VM.
+
+	-D, --no-gdb
+		Don't run an xterm with gdb attached to the guest.
+
+	-r, --root directory
+		Use the specified directory as root directory inside the guest.
+
+	-s, --sdl
+		Enable SDL graphical output.
+
+	-S, --smp cpus
+		Set number of virtual CPUs.
+
+	-v, --vnc
+		Enable VNC graphical output.
+
+Examples:
+
+	Run the host root fs inside a VM:
+	$ ./scripts/run-qemu.sh -r /
+
+	Run the same with SDL:
+	$ ./scripts/run-qemu.sh -r / --sdl
+	
+	Or with a PPC build:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r /
+	
+	PPC with a mac99 model by passing options to QEMU:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+"
+}
+
+function require_config() {
+	if [ "$(grep CONFIG_$1=y .config)" ]; then
+		return
+	fi
+
+	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
+	exit 1
+}
+
+function has_config() {
+	grep -q "CONFIG_$1=y" .config
+}
+
+function drive_if() {
+	if has_config VIRTIO_BLK; then
+		echo virtio
+	elif has_config ATA_PIIX; then
+		echo ide
+	else
+		echo "\
+Your kernel must have either VIRTIO_BLK or ATA_PIIX
+enabled for block device assignment" >&2
+		exit 1
+	fi
+}
+
+GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
+	-n "$(basename \"$0\")" -- "$@"`
+
+if [ $? != 0 ]; then
+	echo "Terminating..." >&2
+	exit 1
+fi
+
+eval set -- "$GETOPT"
+
+while true; do
+	case "$1" in
+	-a|--append)
+		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
+		shift
+		;;
+	-d|--disk)
+		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
+			file=$2,if=$(drive_if),cache=unsafe"
+		USE_DISK=1
+		shift
+		;;
+	-D|--no-gdb)
+		USE_GDB=
+		;;
+	-h|--help)
+		usage
+		exit 0
+		;;
+	-r|--root)
+		ROOTFS="$2"
+		shift
+		;;
+	-s|--sdl)
+		USE_SDL=1
+		;;
+	-S|--smp)
+		SMP="$2"
+		shift
+		;;
+	-v|--vnc)
+		USE_VNC=1
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		echo "Could not parse option: $1" >&2
+		exit 1
+		;;
+	esac
+	shift
+done
+
+if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
+	echo "\
+Error: Please specify at least -r or -d with a target \
+FS to run off of" >&2
+	exit 1
+fi
+
+# Try to find the KVM accelerated QEMU binary
+
+[ "$ARCH" ] || ARCH=$(uname -m)
+case $ARCH in
+x86_64)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	# QEMU's own build system calls it qemu-system-x86_64
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
+	;;
+i*86)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# i386 version of QEMU
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
+	;;
+s390*)
+	KERNEL_BIN=arch/s390/boot/image
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
+	;;
+ppc*)
+	KERNEL_BIN=vmlinux
+
+	IS_64BIT=
+	has_config PPC64 && IS_64BIT=64
+	if has_config PPC_85xx; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
+	elif has_config PPC_PSERIES; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
+		SERIAL=hvc0
+		SERIAL_KCONFIG=HVC_CONSOLE
+	elif has_config PPC_PMAC; then
+		has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
+		SERIAL_KCONFIG=SERIAL_PMACZILOG
+	else
+		echo "Unknown PPC board" >&2
+		exit 1
+	fi
+
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
+	;;
+esac
+
+if [ ! -e "$QEMU_BIN" ]; then
+	echo "\
+Could not find a usable QEMU binary. Please install one from \
+your distro or from source code using:
+
+  $ git clone git://git.qemu.org/qemu.git
+  $ cd qemu
+  $ ./configure
+  $ make -j
+  $ sudo make install
+" >&2
+	exit 1
+fi
+
+# The binaries without kvm in their name can be too old to support KVM, so
+# check for that before the user gets confused
+if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
+     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
+	echo "Your QEMU binary is too old, please update to at least 0.15." >&2
+	exit 1
+fi
+QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
+
+# We need to check some .config variables to make sure we actually work
+# on the respective kernel.
+if [ ! -e .config ]; then
+	echo "\
+Please run this script on a fully compiled and configured
+Linux kernel build directory" >&2
+	exit 1
+fi
+
+if [ ! -e "$KERNEL_BIN" ]; then
+	echo "Could not find kernel binary: $KERNEL_BIN" >&2
+	exit 1
+fi
+
+QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
+
+if [ "$USE_SDL" ]; then
+	# SDL is the default, so nothing to do
+	:
+elif [ "$USE_VNC" ]; then
+	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
+else
+	# When emulating a serial console, tell the kernel to use it as well
+	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
+	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
+	MON_STDIO=1
+	require_config "$SERIAL_KCONFIG"
+fi
+
+if [ "$ROOTFS" ]; then
+	# Using rootfs with 9p
+	require_config "NET_9P_VIRTIO"
+	KERNEL_APPEND="$KERNEL_APPEND \
+root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
+
+#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
+
+
+	QEMU_OPTIONS="$QEMU_OPTIONS \
+-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
+-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
+fi
+
+[ "$SMP" ] || SMP=1
+
+# User append args come last
+KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
+
+############### Execution #################
+
+QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
+
+echo "
+	################# Linux QEMU launcher #################
+
+This script executes your currently built Linux kernel using QEMU. If KVM is
+available, it will also use KVM for fast virtualization of your guest.
+
+The intent is to make it very easy to run your kernel. If you need to do more
+advanced things, such as passing through real devices, please use QEMU command
+line options and add them to the $BASENAME command line using --.
+
+This tool is for simplicity, not world dominating functionality coverage.
+(just a hobby, won't be big and professional like libvirt)
+
+"
+
+if [ "$MON_STDIO" ]; then
+	echo "\
+### Your guest is bound to the current foreground shell. To quit the guest, ###
+### please use Ctrl-A x                                                     ###
+"
+fi
+
+echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""
+echo
+
+GDB_PID=
+if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
+	# Run a gdb console in parallel to the kernel
+
+	# XXX find out if port is in use
+	PORT=$$
+	xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
+	GDB_PID=$!
+	QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
+fi
+
+$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
+wait $GDB_PID &>/dev/null
+
-- 
1.6.0.2

[Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
would be doing and what he expects from it. Basically he wants a
small and simple tool he and other developers can run to try out and
see if the kernel they just built actually works.

Fortunately, QEMU can do that today already! The only piece that was
missing was the "simple" piece of the equation, so here is a script
that wraps around QEMU and executes a kernel you just built.

If you do have KVM around and are not cross-compiling, it will use
KVM. But if you don't, you can still fall back to emulation mode and
at least check if your kernel still does what you expect. I only
implemented support for s390x and ppc there, but it's easily extensible
to more platforms, as QEMU can emulate (and virtualize) pretty much
any platform out there.

If you don't have qemu installed, please do so before using this script. Your
distro should provide a package for it (might even call it "kvm"). If not,
just compile it from source - it's not hard!

To quickly get going, just execute the following as user:

    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash

This will drop you into a shell on your rootfs.

Happy hacking!

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - fix naming of QEMU
  - use grep -q for has_config
  - support multiple -a args
  - spawn gdb on execution
  - pass through qemu options
  - dont use qemu-system-x86_64 on i386
  - add funny sentence to startup text
  - more helpful error messages
---
 scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 334 insertions(+), 0 deletions(-)
 create mode 100755 scripts/run-qemu.sh

diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
new file mode 100755
index 0000000..5d4e185
--- /dev/null
+++ b/scripts/run-qemu.sh
@@ -0,0 +1,334 @@
+#!/bin/bash
+#
+# QEMU Launcher
+#
+# This script enables simple use of the KVM and QEMU tool stack for
+# easy kernel testing. It allows to pass either a host directory to
+# the guest or a disk image. Example usage:
+#
+# Run the host root fs inside a VM:
+#
+# $ ./scripts/run-qemu.sh -r /
+#
+# Run the same with SDL:
+#
+# $ ./scripts/run-qemu.sh -r / --sdl
+# 
+# Or with a PPC build:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r /
+# 
+# PPC with a mac99 model by passing options to QEMU:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+#
+
+USE_SDL=
+USE_VNC=
+USE_GDB=1
+KERNEL_BIN=arch/x86/boot/bzImage
+MON_STDIO=
+KERNEL_APPEND2=
+SERIAL=ttyS0
+SERIAL_KCONFIG=SERIAL_8250
+BASENAME=$(basename "$0")
+
+function usage() {
+	echo "
+$BASENAME allows you to execute a virtual machine with the Linux kernel
+that you just built. To only execute a simple VM, you can just run it
+on your root fs with \"-r / -a init=/bin/bash\"
+
+	-a, --append parameters
+		Append the given parameters to the kernel command line.
+
+	-d, --disk image
+		Add the image file as disk into the VM.
+
+	-D, --no-gdb
+		Don't run an xterm with gdb attached to the guest.
+
+	-r, --root directory
+		Use the specified directory as root directory inside the guest.
+
+	-s, --sdl
+		Enable SDL graphical output.
+
+	-S, --smp cpus
+		Set number of virtual CPUs.
+
+	-v, --vnc
+		Enable VNC graphical output.
+
+Examples:
+
+	Run the host root fs inside a VM:
+	$ ./scripts/run-qemu.sh -r /
+
+	Run the same with SDL:
+	$ ./scripts/run-qemu.sh -r / --sdl
+	
+	Or with a PPC build:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r /
+	
+	PPC with a mac99 model by passing options to QEMU:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+"
+}
+
+function require_config() {
+	if [ "$(grep CONFIG_$1=y .config)" ]; then
+		return
+	fi
+
+	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
+	exit 1
+}
+
+function has_config() {
+	grep -q "CONFIG_$1=y" .config
+}
+
+function drive_if() {
+	if has_config VIRTIO_BLK; then
+		echo virtio
+	elif has_config ATA_PIIX; then
+		echo ide
+	else
+		echo "\
+Your kernel must have either VIRTIO_BLK or ATA_PIIX
+enabled for block device assignment" >&2
+		exit 1
+	fi
+}
+
+GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
+	-n "$(basename \"$0\")" -- "$@"`
+
+if [ $? != 0 ]; then
+	echo "Terminating..." >&2
+	exit 1
+fi
+
+eval set -- "$GETOPT"
+
+while true; do
+	case "$1" in
+	-a|--append)
+		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
+		shift
+		;;
+	-d|--disk)
+		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
+			file=$2,if=$(drive_if),cache=unsafe"
+		USE_DISK=1
+		shift
+		;;
+	-D|--no-gdb)
+		USE_GDB=
+		;;
+	-h|--help)
+		usage
+		exit 0
+		;;
+	-r|--root)
+		ROOTFS="$2"
+		shift
+		;;
+	-s|--sdl)
+		USE_SDL=1
+		;;
+	-S|--smp)
+		SMP="$2"
+		shift
+		;;
+	-v|--vnc)
+		USE_VNC=1
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		echo "Could not parse option: $1" >&2
+		exit 1
+		;;
+	esac
+	shift
+done
+
+if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
+	echo "\
+Error: Please specify at least -r or -d with a target \
+FS to run off of" >&2
+	exit 1
+fi
+
+# Try to find the KVM accelerated QEMU binary
+
+[ "$ARCH" ] || ARCH=$(uname -m)
+case $ARCH in
+x86_64)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	# QEMU's own build system calls it qemu-system-x86_64
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
+	;;
+i*86)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# i386 version of QEMU
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
+	;;
+s390*)
+	KERNEL_BIN=arch/s390/boot/image
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
+	;;
+ppc*)
+	KERNEL_BIN=vmlinux
+
+	IS_64BIT=
+	has_config PPC64 && IS_64BIT=64
+	if has_config PPC_85xx; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
+	elif has_config PPC_PSERIES; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
+		SERIAL=hvc0
+		SERIAL_KCONFIG=HVC_CONSOLE
+	elif has_config PPC_PMAC; then
+		has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
+		SERIAL_KCONFIG=SERIAL_PMACZILOG
+	else
+		echo "Unknown PPC board" >&2
+		exit 1
+	fi
+
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
+	;;
+esac
+
+if [ ! -e "$QEMU_BIN" ]; then
+	echo "\
+Could not find a usable QEMU binary. Please install one from \
+your distro or from source code using:
+
+  $ git clone git://git.qemu.org/qemu.git
+  $ cd qemu
+  $ ./configure
+  $ make -j
+  $ sudo make install
+" >&2
+	exit 1
+fi
+
+# The binaries without kvm in their name can be too old to support KVM, so
+# check for that before the user gets confused
+if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
+     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
+	echo "Your QEMU binary is too old, please update to at least 0.15." >&2
+	exit 1
+fi
+QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
+
+# We need to check some .config variables to make sure we actually work
+# on the respective kernel.
+if [ ! -e .config ]; then
+	echo "\
+Please run this script on a fully compiled and configured
+Linux kernel build directory" >&2
+	exit 1
+fi
+
+if [ ! -e "$KERNEL_BIN" ]; then
+	echo "Could not find kernel binary: $KERNEL_BIN" >&2
+	exit 1
+fi
+
+QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
+
+if [ "$USE_SDL" ]; then
+	# SDL is the default, so nothing to do
+	:
+elif [ "$USE_VNC" ]; then
+	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
+else
+	# When emulating a serial console, tell the kernel to use it as well
+	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
+	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
+	MON_STDIO=1
+	require_config "$SERIAL_KCONFIG"
+fi
+
+if [ "$ROOTFS" ]; then
+	# Using rootfs with 9p
+	require_config "NET_9P_VIRTIO"
+	KERNEL_APPEND="$KERNEL_APPEND \
+root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
+
+#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
+
+
+	QEMU_OPTIONS="$QEMU_OPTIONS \
+-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
+-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
+fi
+
+[ "$SMP" ] || SMP=1
+
+# User append args come last
+KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
+
+############### Execution #################
+
+QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
+
+echo "
+	################# Linux QEMU launcher #################
+
+This script executes your currently built Linux kernel using QEMU. If KVM is
+available, it will also use KVM for fast virtualization of your guest.
+
+The intent is to make it very easy to run your kernel. If you need to do more
+advanced things, such as passing through real devices, please use QEMU command
+line options and add them to the $BASENAME command line using --.
+
+This tool is for simplicity, not world dominating functionality coverage.
+(just a hobby, won't be big and professional like libvirt)
+
+"
+
+if [ "$MON_STDIO" ]; then
+	echo "\
+### Your guest is bound to the current foreground shell. To quit the guest, ###
+### please use Ctrl-A x                                                     ###
+"
+fi
+
+echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""
+echo
+
+GDB_PID=
+if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
+	# Run a gdb console in parallel to the kernel
+
+	# XXX find out if port is in use
+	PORT=$$
+	xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
+	GDB_PID=$!
+	QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
+fi
+
+$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
+wait $GDB_PID &>/dev/null
+
-- 
1.6.0.2

Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Blue Swirl]

On Wed, Aug 24, 2011 at 9:38 PM, Alexander Graf <agraf@suse.de> wrote:
> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> would be doing and what he expects from it. Basically he wants a
> small and simple tool he and other developers can run to try out and
> see if the kernel they just built actually works.
>
> Fortunately, QEMU can do that today already! The only piece that was
> missing was the "simple" piece of the equation, so here is a script
> that wraps around QEMU and executes a kernel you just built.
>
> If you do have KVM around and are not cross-compiling, it will use
> KVM. But if you don't, you can still fall back to emulation mode and
> at least check if your kernel still does what you expect. I only
> implemented support for s390x and ppc there, but it's easily extensible
> to more platforms, as QEMU can emulate (and virtualize) pretty much
> any platform out there.
>
> If you don't have qemu installed, please do so before using this script. Your
> distro should provide a package for it (might even call it "kvm"). If not,
> just compile it from source - it's not hard!
>
> To quickly get going, just execute the following as user:
>
>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>
> This will drop you into a shell on your rootfs.
>
> Happy hacking!
>
> Signed-off-by: Alexander Graf <agraf@suse.de>
>
> ---
>
> v1 -> v2:
>
>  - fix naming of QEMU
>  - use grep -q for has_config
>  - support multiple -a args
>  - spawn gdb on execution
>  - pass through qemu options
>  - dont use qemu-system-x86_64 on i386
>  - add funny sentence to startup text
>  - more helpful error messages
> ---
>  scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 334 insertions(+), 0 deletions(-)
>  create mode 100755 scripts/run-qemu.sh
>
> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
> new file mode 100755
> index 0000000..5d4e185
> --- /dev/null
> +++ b/scripts/run-qemu.sh
> @@ -0,0 +1,334 @@
> +#!/bin/bash
> +#
> +# QEMU Launcher
> +#
> +# This script enables simple use of the KVM and QEMU tool stack for
> +# easy kernel testing. It allows to pass either a host directory to
> +# the guest or a disk image. Example usage:
> +#
> +# Run the host root fs inside a VM:
> +#
> +# $ ./scripts/run-qemu.sh -r /
> +#
> +# Run the same with SDL:
> +#
> +# $ ./scripts/run-qemu.sh -r / --sdl
> +#
> +# Or with a PPC build:
> +#
> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
> +#
> +# PPC with a mac99 model by passing options to QEMU:
> +#
> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
> +#
> +
> +USE_SDL=
> +USE_VNC=
> +USE_GDB=1
> +KERNEL_BIN=arch/x86/boot/bzImage
> +MON_STDIO=
> +KERNEL_APPEND2=
> +SERIAL=ttyS0
> +SERIAL_KCONFIG=SERIAL_8250
> +BASENAME=$(basename "$0")
> +
> +function usage() {
> +       echo "
> +$BASENAME allows you to execute a virtual machine with the Linux kernel
> +that you just built. To only execute a simple VM, you can just run it
> +on your root fs with \"-r / -a init=/bin/bash\"
> +
> +       -a, --append parameters
> +               Append the given parameters to the kernel command line.
> +
> +       -d, --disk image
> +               Add the image file as disk into the VM.
> +
> +       -D, --no-gdb
> +               Don't run an xterm with gdb attached to the guest.
> +
> +       -r, --root directory
> +               Use the specified directory as root directory inside the guest.
> +
> +       -s, --sdl
> +               Enable SDL graphical output.
> +
> +       -S, --smp cpus
> +               Set number of virtual CPUs.
> +
> +       -v, --vnc
> +               Enable VNC graphical output.
> +
> +Examples:
> +
> +       Run the host root fs inside a VM:
> +       $ ./scripts/run-qemu.sh -r /
> +
> +       Run the same with SDL:
> +       $ ./scripts/run-qemu.sh -r / --sdl
> +
> +       Or with a PPC build:
> +       $ ARCH=ppc ./scripts/run-qemu.sh -r /
> +
> +       PPC with a mac99 model by passing options to QEMU:
> +       $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
> +"
> +}
> +
> +function require_config() {
> +       if [ "$(grep CONFIG_$1=y .config)" ]; then
> +               return
> +       fi
> +
> +       echo "You need to enable CONFIG_$1 for run-qemu to work properly"
> +       exit 1
> +}
> +
> +function has_config() {
> +       grep -q "CONFIG_$1=y" .config
> +}
> +
> +function drive_if() {
> +       if has_config VIRTIO_BLK; then
> +               echo virtio
> +       elif has_config ATA_PIIX; then
> +               echo ide
> +       else
> +               echo "\
> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
> +enabled for block device assignment" >&2
> +               exit 1
> +       fi
> +}
> +
> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
> +       -n "$(basename \"$0\")" -- "$@"`
> +
> +if [ $? != 0 ]; then
> +       echo "Terminating..." >&2
> +       exit 1
> +fi
> +
> +eval set -- "$GETOPT"
> +
> +while true; do
> +       case "$1" in
> +       -a|--append)
> +               KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
> +               shift
> +               ;;
> +       -d|--disk)
> +               QEMU_OPTIONS="$QEMU_OPTIONS -drive \
> +                       file=$2,if=$(drive_if),cache=unsafe"
> +               USE_DISK=1
> +               shift
> +               ;;
> +       -D|--no-gdb)
> +               USE_GDB=
> +               ;;
> +       -h|--help)
> +               usage
> +               exit 0
> +               ;;
> +       -r|--root)
> +               ROOTFS="$2"
> +               shift
> +               ;;
> +       -s|--sdl)
> +               USE_SDL=1
> +               ;;
> +       -S|--smp)
> +               SMP="$2"
> +               shift
> +               ;;
> +       -v|--vnc)
> +               USE_VNC=1
> +               ;;
> +       --)
> +               shift
> +               break
> +               ;;
> +       *)
> +               echo "Could not parse option: $1" >&2
> +               exit 1
> +               ;;
> +       esac
> +       shift
> +done
> +
> +if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
> +       echo "\
> +Error: Please specify at least -r or -d with a target \
> +FS to run off of" >&2
> +       exit 1
> +fi
> +
> +# Try to find the KVM accelerated QEMU binary
> +
> +[ "$ARCH" ] || ARCH=$(uname -m)
> +case $ARCH in
> +x86_64)
> +       KERNEL_BIN=arch/x86/boot/bzImage
> +       # SUSE and Red Hat call the binary qemu-kvm
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
> +
> +       # Debian and Gentoo call it kvm
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
> +
> +       # QEMU's own build system calls it qemu-system-x86_64
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
> +       ;;
> +i*86)
> +       KERNEL_BIN=arch/x86/boot/bzImage
> +       # SUSE and Red Hat call the binary qemu-kvm
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
> +
> +       # Debian and Gentoo call it kvm
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
> +
> +       KERNEL_BIN=arch/x86/boot/bzImage
> +       # i386 version of QEMU
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
> +       ;;
> +s390*)
> +       KERNEL_BIN=arch/s390/boot/image
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
> +       ;;
> +ppc*)
> +       KERNEL_BIN=vmlinux
> +
> +       IS_64BIT=
> +       has_config PPC64 && IS_64BIT=64
> +       if has_config PPC_85xx; then
> +               QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
> +       elif has_config PPC_PSERIES; then
> +               QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
> +               SERIAL=hvc0
> +               SERIAL_KCONFIG=HVC_CONSOLE
> +       elif has_config PPC_PMAC; then
> +               has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
> +               SERIAL_KCONFIG=SERIAL_PMACZILOG
> +       else
> +               echo "Unknown PPC board" >&2
> +               exit 1
> +       fi
> +
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
> +       ;;
> +esac
> +
> +if [ ! -e "$QEMU_BIN" ]; then
> +       echo "\
> +Could not find a usable QEMU binary. Please install one from \
> +your distro or from source code using:
> +
> +  $ git clone git://git.qemu.org/qemu.git
> +  $ cd qemu
> +  $ ./configure
> +  $ make -j
> +  $ sudo make install
> +" >&2
> +       exit 1
> +fi
> +
> +# The binaries without kvm in their name can be too old to support KVM, so
> +# check for that before the user gets confused
> +if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
> +     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
> +       echo "Your QEMU binary is too old, please update to at least 0.15." >&2
> +       exit 1
> +fi
> +QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
> +
> +# We need to check some .config variables to make sure we actually work
> +# on the respective kernel.
> +if [ ! -e .config ]; then
> +       echo "\
> +Please run this script on a fully compiled and configured
> +Linux kernel build directory" >&2
> +       exit 1
> +fi
> +
> +if [ ! -e "$KERNEL_BIN" ]; then
> +       echo "Could not find kernel binary: $KERNEL_BIN" >&2
> +       exit 1
> +fi
> +
> +QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
> +
> +if [ "$USE_SDL" ]; then
> +       # SDL is the default, so nothing to do
> +       :
> +elif [ "$USE_VNC" ]; then
> +       QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
> +else
> +       # When emulating a serial console, tell the kernel to use it as well
> +       QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
> +       KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
> +       MON_STDIO=1
> +       require_config "$SERIAL_KCONFIG"
> +fi
> +
> +if [ "$ROOTFS" ]; then
> +       # Using rootfs with 9p
> +       require_config "NET_9P_VIRTIO"
> +       KERNEL_APPEND="$KERNEL_APPEND \
> +root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
> +
> +#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
> +
> +
> +       QEMU_OPTIONS="$QEMU_OPTIONS \
> +-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
> +-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
> +fi
> +
> +[ "$SMP" ] || SMP=1
> +
> +# User append args come last
> +KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
> +
> +############### Execution #################
> +
> +QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
> +
> +echo "
> +       ################# Linux QEMU launcher #################
> +
> +This script executes your currently built Linux kernel using QEMU. If KVM is
> +available, it will also use KVM for fast virtualization of your guest.
> +
> +The intent is to make it very easy to run your kernel. If you need to do more
> +advanced things, such as passing through real devices, please use QEMU command
> +line options and add them to the $BASENAME command line using --.
> +
> +This tool is for simplicity, not world dominating functionality coverage.
> +(just a hobby, won't be big and professional like libvirt)
> +
> +"
> +
> +if [ "$MON_STDIO" ]; then
> +       echo "\
> +### Your guest is bound to the current foreground shell. To quit the guest, ###
> +### please use Ctrl-A x                                                     ###
> +"
> +fi
> +
> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""

This line does not match [1] below.

> +echo
> +
> +GDB_PID=
> +if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
> +       # Run a gdb console in parallel to the kernel
> +
> +       # XXX find out if port is in use
> +       PORT=$$

$$ could be <1024.

> +       xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &

But the gnomes might not have xterms but instead gterms and so on.
Then there are wrappers like x-terminal-emulator on some distros.

> +       GDB_PID=$!
> +       QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
> +fi
> +
> +$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"

[1]

> +wait $GDB_PID &>/dev/null
> +
> --
> 1.6.0.2
>
>
>

Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Blue Swirl]

On Wed, Aug 24, 2011 at 9:38 PM, Alexander Graf <agraf@suse.de> wrote:
> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> would be doing and what he expects from it. Basically he wants a
> small and simple tool he and other developers can run to try out and
> see if the kernel they just built actually works.
>
> Fortunately, QEMU can do that today already! The only piece that was
> missing was the "simple" piece of the equation, so here is a script
> that wraps around QEMU and executes a kernel you just built.
>
> If you do have KVM around and are not cross-compiling, it will use
> KVM. But if you don't, you can still fall back to emulation mode and
> at least check if your kernel still does what you expect. I only
> implemented support for s390x and ppc there, but it's easily extensible
> to more platforms, as QEMU can emulate (and virtualize) pretty much
> any platform out there.
>
> If you don't have qemu installed, please do so before using this script. Your
> distro should provide a package for it (might even call it "kvm"). If not,
> just compile it from source - it's not hard!
>
> To quickly get going, just execute the following as user:
>
>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>
> This will drop you into a shell on your rootfs.
>
> Happy hacking!
>
> Signed-off-by: Alexander Graf <agraf@suse.de>
>
> ---
>
> v1 -> v2:
>
>  - fix naming of QEMU
>  - use grep -q for has_config
>  - support multiple -a args
>  - spawn gdb on execution
>  - pass through qemu options
>  - dont use qemu-system-x86_64 on i386
>  - add funny sentence to startup text
>  - more helpful error messages
> ---
>  scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 334 insertions(+), 0 deletions(-)
>  create mode 100755 scripts/run-qemu.sh
>
> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
> new file mode 100755
> index 0000000..5d4e185
> --- /dev/null
> +++ b/scripts/run-qemu.sh
> @@ -0,0 +1,334 @@
> +#!/bin/bash
> +#
> +# QEMU Launcher
> +#
> +# This script enables simple use of the KVM and QEMU tool stack for
> +# easy kernel testing. It allows to pass either a host directory to
> +# the guest or a disk image. Example usage:
> +#
> +# Run the host root fs inside a VM:
> +#
> +# $ ./scripts/run-qemu.sh -r /
> +#
> +# Run the same with SDL:
> +#
> +# $ ./scripts/run-qemu.sh -r / --sdl
> +#
> +# Or with a PPC build:
> +#
> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
> +#
> +# PPC with a mac99 model by passing options to QEMU:
> +#
> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
> +#
> +
> +USE_SDL=
> +USE_VNC=
> +USE_GDB=1
> +KERNEL_BIN=arch/x86/boot/bzImage
> +MON_STDIO=
> +KERNEL_APPEND2=
> +SERIAL=ttyS0
> +SERIAL_KCONFIG=SERIAL_8250
> +BASENAME=$(basename "$0")
> +
> +function usage() {
> +       echo "
> +$BASENAME allows you to execute a virtual machine with the Linux kernel
> +that you just built. To only execute a simple VM, you can just run it
> +on your root fs with \"-r / -a init=/bin/bash\"
> +
> +       -a, --append parameters
> +               Append the given parameters to the kernel command line.
> +
> +       -d, --disk image
> +               Add the image file as disk into the VM.
> +
> +       -D, --no-gdb
> +               Don't run an xterm with gdb attached to the guest.
> +
> +       -r, --root directory
> +               Use the specified directory as root directory inside the guest.
> +
> +       -s, --sdl
> +               Enable SDL graphical output.
> +
> +       -S, --smp cpus
> +               Set number of virtual CPUs.
> +
> +       -v, --vnc
> +               Enable VNC graphical output.
> +
> +Examples:
> +
> +       Run the host root fs inside a VM:
> +       $ ./scripts/run-qemu.sh -r /
> +
> +       Run the same with SDL:
> +       $ ./scripts/run-qemu.sh -r / --sdl
> +
> +       Or with a PPC build:
> +       $ ARCH=ppc ./scripts/run-qemu.sh -r /
> +
> +       PPC with a mac99 model by passing options to QEMU:
> +       $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
> +"
> +}
> +
> +function require_config() {
> +       if [ "$(grep CONFIG_$1=y .config)" ]; then
> +               return
> +       fi
> +
> +       echo "You need to enable CONFIG_$1 for run-qemu to work properly"
> +       exit 1
> +}
> +
> +function has_config() {
> +       grep -q "CONFIG_$1=y" .config
> +}
> +
> +function drive_if() {
> +       if has_config VIRTIO_BLK; then
> +               echo virtio
> +       elif has_config ATA_PIIX; then
> +               echo ide
> +       else
> +               echo "\
> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
> +enabled for block device assignment" >&2
> +               exit 1
> +       fi
> +}
> +
> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
> +       -n "$(basename \"$0\")" -- "$@"`
> +
> +if [ $? != 0 ]; then
> +       echo "Terminating..." >&2
> +       exit 1
> +fi
> +
> +eval set -- "$GETOPT"
> +
> +while true; do
> +       case "$1" in
> +       -a|--append)
> +               KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
> +               shift
> +               ;;
> +       -d|--disk)
> +               QEMU_OPTIONS="$QEMU_OPTIONS -drive \
> +                       file=$2,if=$(drive_if),cache=unsafe"
> +               USE_DISK=1
> +               shift
> +               ;;
> +       -D|--no-gdb)
> +               USE_GDB=
> +               ;;
> +       -h|--help)
> +               usage
> +               exit 0
> +               ;;
> +       -r|--root)
> +               ROOTFS="$2"
> +               shift
> +               ;;
> +       -s|--sdl)
> +               USE_SDL=1
> +               ;;
> +       -S|--smp)
> +               SMP="$2"
> +               shift
> +               ;;
> +       -v|--vnc)
> +               USE_VNC=1
> +               ;;
> +       --)
> +               shift
> +               break
> +               ;;
> +       *)
> +               echo "Could not parse option: $1" >&2
> +               exit 1
> +               ;;
> +       esac
> +       shift
> +done
> +
> +if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
> +       echo "\
> +Error: Please specify at least -r or -d with a target \
> +FS to run off of" >&2
> +       exit 1
> +fi
> +
> +# Try to find the KVM accelerated QEMU binary
> +
> +[ "$ARCH" ] || ARCH=$(uname -m)
> +case $ARCH in
> +x86_64)
> +       KERNEL_BIN=arch/x86/boot/bzImage
> +       # SUSE and Red Hat call the binary qemu-kvm
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
> +
> +       # Debian and Gentoo call it kvm
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
> +
> +       # QEMU's own build system calls it qemu-system-x86_64
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
> +       ;;
> +i*86)
> +       KERNEL_BIN=arch/x86/boot/bzImage
> +       # SUSE and Red Hat call the binary qemu-kvm
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
> +
> +       # Debian and Gentoo call it kvm
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
> +
> +       KERNEL_BIN=arch/x86/boot/bzImage
> +       # i386 version of QEMU
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
> +       ;;
> +s390*)
> +       KERNEL_BIN=arch/s390/boot/image
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
> +       ;;
> +ppc*)
> +       KERNEL_BIN=vmlinux
> +
> +       IS_64BIT=
> +       has_config PPC64 && IS_64BIT=64
> +       if has_config PPC_85xx; then
> +               QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
> +       elif has_config PPC_PSERIES; then
> +               QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
> +               SERIAL=hvc0
> +               SERIAL_KCONFIG=HVC_CONSOLE
> +       elif has_config PPC_PMAC; then
> +               has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
> +               SERIAL_KCONFIG=SERIAL_PMACZILOG
> +       else
> +               echo "Unknown PPC board" >&2
> +               exit 1
> +       fi
> +
> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
> +       ;;
> +esac
> +
> +if [ ! -e "$QEMU_BIN" ]; then
> +       echo "\
> +Could not find a usable QEMU binary. Please install one from \
> +your distro or from source code using:
> +
> +  $ git clone git://git.qemu.org/qemu.git
> +  $ cd qemu
> +  $ ./configure
> +  $ make -j
> +  $ sudo make install
> +" >&2
> +       exit 1
> +fi
> +
> +# The binaries without kvm in their name can be too old to support KVM, so
> +# check for that before the user gets confused
> +if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
> +     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
> +       echo "Your QEMU binary is too old, please update to at least 0.15." >&2
> +       exit 1
> +fi
> +QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
> +
> +# We need to check some .config variables to make sure we actually work
> +# on the respective kernel.
> +if [ ! -e .config ]; then
> +       echo "\
> +Please run this script on a fully compiled and configured
> +Linux kernel build directory" >&2
> +       exit 1
> +fi
> +
> +if [ ! -e "$KERNEL_BIN" ]; then
> +       echo "Could not find kernel binary: $KERNEL_BIN" >&2
> +       exit 1
> +fi
> +
> +QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
> +
> +if [ "$USE_SDL" ]; then
> +       # SDL is the default, so nothing to do
> +       :
> +elif [ "$USE_VNC" ]; then
> +       QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
> +else
> +       # When emulating a serial console, tell the kernel to use it as well
> +       QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
> +       KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
> +       MON_STDIO=1
> +       require_config "$SERIAL_KCONFIG"
> +fi
> +
> +if [ "$ROOTFS" ]; then
> +       # Using rootfs with 9p
> +       require_config "NET_9P_VIRTIO"
> +       KERNEL_APPEND="$KERNEL_APPEND \
> +root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
> +
> +#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
> +
> +
> +       QEMU_OPTIONS="$QEMU_OPTIONS \
> +-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
> +-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
> +fi
> +
> +[ "$SMP" ] || SMP=1
> +
> +# User append args come last
> +KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
> +
> +############### Execution #################
> +
> +QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
> +
> +echo "
> +       ################# Linux QEMU launcher #################
> +
> +This script executes your currently built Linux kernel using QEMU. If KVM is
> +available, it will also use KVM for fast virtualization of your guest.
> +
> +The intent is to make it very easy to run your kernel. If you need to do more
> +advanced things, such as passing through real devices, please use QEMU command
> +line options and add them to the $BASENAME command line using --.
> +
> +This tool is for simplicity, not world dominating functionality coverage.
> +(just a hobby, won't be big and professional like libvirt)
> +
> +"
> +
> +if [ "$MON_STDIO" ]; then
> +       echo "\
> +### Your guest is bound to the current foreground shell. To quit the guest, ###
> +### please use Ctrl-A x                                                     ###
> +"
> +fi
> +
> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""

This line does not match [1] below.

> +echo
> +
> +GDB_PID=
> +if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
> +       # Run a gdb console in parallel to the kernel
> +
> +       # XXX find out if port is in use
> +       PORT=$$

$$ could be <1024.

> +       xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &

But the gnomes might not have xterms but instead gterms and so on.
Then there are wrappers like x-terminal-emulator on some distros.

> +       GDB_PID=$!
> +       QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
> +fi
> +
> +$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"

[1]

> +wait $GDB_PID &>/dev/null
> +
> --
> 1.6.0.2
>
>
>

Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 25.08.2011, at 11:01, Blue Swirl wrote:

> On Wed, Aug 24, 2011 at 9:38 PM, Alexander Graf <agraf@suse.de> wrote:
>> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
>> would be doing and what he expects from it. Basically he wants a
>> small and simple tool he and other developers can run to try out and
>> see if the kernel they just built actually works.
>> 
>> Fortunately, QEMU can do that today already! The only piece that was
>> missing was the "simple" piece of the equation, so here is a script
>> that wraps around QEMU and executes a kernel you just built.
>> 
>> If you do have KVM around and are not cross-compiling, it will use
>> KVM. But if you don't, you can still fall back to emulation mode and
>> at least check if your kernel still does what you expect. I only
>> implemented support for s390x and ppc there, but it's easily extensible
>> to more platforms, as QEMU can emulate (and virtualize) pretty much
>> any platform out there.
>> 
>> If you don't have qemu installed, please do so before using this script. Your
>> distro should provide a package for it (might even call it "kvm"). If not,
>> just compile it from source - it's not hard!
>> 
>> To quickly get going, just execute the following as user:
>> 
>>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>> 
>> This will drop you into a shell on your rootfs.
>> 
>> Happy hacking!
>> 
>> Signed-off-by: Alexander Graf <agraf@suse.de>
>> 
>> ---
>> 
>> v1 -> v2:
>> 
>>  - fix naming of QEMU
>>  - use grep -q for has_config
>>  - support multiple -a args
>>  - spawn gdb on execution
>>  - pass through qemu options
>>  - dont use qemu-system-x86_64 on i386
>>  - add funny sentence to startup text
>>  - more helpful error messages
>> ---
>>  scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 files changed, 334 insertions(+), 0 deletions(-)
>>  create mode 100755 scripts/run-qemu.sh
>> 
>> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
>> new file mode 100755
>> index 0000000..5d4e185
>> --- /dev/null
>> +++ b/scripts/run-qemu.sh
>> @@ -0,0 +1,334 @@
>> +#!/bin/bash
>> +#
>> +# QEMU Launcher
>> +#
>> +# This script enables simple use of the KVM and QEMU tool stack for
>> +# easy kernel testing. It allows to pass either a host directory to
>> +# the guest or a disk image. Example usage:
>> +#
>> +# Run the host root fs inside a VM:
>> +#
>> +# $ ./scripts/run-qemu.sh -r /
>> +#
>> +# Run the same with SDL:
>> +#
>> +# $ ./scripts/run-qemu.sh -r / --sdl
>> +#
>> +# Or with a PPC build:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +#
>> +# PPC with a mac99 model by passing options to QEMU:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +#
>> +
>> +USE_SDL=
>> +USE_VNC=
>> +USE_GDB=1
>> +KERNEL_BIN=arch/x86/boot/bzImage
>> +MON_STDIO=
>> +KERNEL_APPEND2=
>> +SERIAL=ttyS0
>> +SERIAL_KCONFIG=SERIAL_8250
>> +BASENAME=$(basename "$0")
>> +
>> +function usage() {
>> +       echo "
>> +$BASENAME allows you to execute a virtual machine with the Linux kernel
>> +that you just built. To only execute a simple VM, you can just run it
>> +on your root fs with \"-r / -a init=/bin/bash\"
>> +
>> +       -a, --append parameters
>> +               Append the given parameters to the kernel command line.
>> +
>> +       -d, --disk image
>> +               Add the image file as disk into the VM.
>> +
>> +       -D, --no-gdb
>> +               Don't run an xterm with gdb attached to the guest.
>> +
>> +       -r, --root directory
>> +               Use the specified directory as root directory inside the guest.
>> +
>> +       -s, --sdl
>> +               Enable SDL graphical output.
>> +
>> +       -S, --smp cpus
>> +               Set number of virtual CPUs.
>> +
>> +       -v, --vnc
>> +               Enable VNC graphical output.
>> +
>> +Examples:
>> +
>> +       Run the host root fs inside a VM:
>> +       $ ./scripts/run-qemu.sh -r /
>> +
>> +       Run the same with SDL:
>> +       $ ./scripts/run-qemu.sh -r / --sdl
>> +
>> +       Or with a PPC build:
>> +       $ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +
>> +       PPC with a mac99 model by passing options to QEMU:
>> +       $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +"
>> +}
>> +
>> +function require_config() {
>> +       if [ "$(grep CONFIG_$1=y .config)" ]; then
>> +               return
>> +       fi
>> +
>> +       echo "You need to enable CONFIG_$1 for run-qemu to work properly"
>> +       exit 1
>> +}
>> +
>> +function has_config() {
>> +       grep -q "CONFIG_$1=y" .config
>> +}
>> +
>> +function drive_if() {
>> +       if has_config VIRTIO_BLK; then
>> +               echo virtio
>> +       elif has_config ATA_PIIX; then
>> +               echo ide
>> +       else
>> +               echo "\
>> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
>> +enabled for block device assignment" >&2
>> +               exit 1
>> +       fi
>> +}
>> +
>> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
>> +       -n "$(basename \"$0\")" -- "$@"`
>> +
>> +if [ $? != 0 ]; then
>> +       echo "Terminating..." >&2
>> +       exit 1
>> +fi
>> +
>> +eval set -- "$GETOPT"
>> +
>> +while true; do
>> +       case "$1" in
>> +       -a|--append)
>> +               KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
>> +               shift
>> +               ;;
>> +       -d|--disk)
>> +               QEMU_OPTIONS="$QEMU_OPTIONS -drive \
>> +                       file=$2,if=$(drive_if),cache=unsafe"
>> +               USE_DISK=1
>> +               shift
>> +               ;;
>> +       -D|--no-gdb)
>> +               USE_GDB=
>> +               ;;
>> +       -h|--help)
>> +               usage
>> +               exit 0
>> +               ;;
>> +       -r|--root)
>> +               ROOTFS="$2"
>> +               shift
>> +               ;;
>> +       -s|--sdl)
>> +               USE_SDL=1
>> +               ;;
>> +       -S|--smp)
>> +               SMP="$2"
>> +               shift
>> +               ;;
>> +       -v|--vnc)
>> +               USE_VNC=1
>> +               ;;
>> +       --)
>> +               shift
>> +               break
>> +               ;;
>> +       *)
>> +               echo "Could not parse option: $1" >&2
>> +               exit 1
>> +               ;;
>> +       esac
>> +       shift
>> +done
>> +
>> +if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
>> +       echo "\
>> +Error: Please specify at least -r or -d with a target \
>> +FS to run off of" >&2
>> +       exit 1
>> +fi
>> +
>> +# Try to find the KVM accelerated QEMU binary
>> +
>> +[ "$ARCH" ] || ARCH=$(uname -m)
>> +case $ARCH in
>> +x86_64)
>> +       KERNEL_BIN=arch/x86/boot/bzImage
>> +       # SUSE and Red Hat call the binary qemu-kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
>> +
>> +       # Debian and Gentoo call it kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
>> +
>> +       # QEMU's own build system calls it qemu-system-x86_64
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
>> +       ;;
>> +i*86)
>> +       KERNEL_BIN=arch/x86/boot/bzImage
>> +       # SUSE and Red Hat call the binary qemu-kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
>> +
>> +       # Debian and Gentoo call it kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
>> +
>> +       KERNEL_BIN=arch/x86/boot/bzImage
>> +       # i386 version of QEMU
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
>> +       ;;
>> +s390*)
>> +       KERNEL_BIN=arch/s390/boot/image
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
>> +       ;;
>> +ppc*)
>> +       KERNEL_BIN=vmlinux
>> +
>> +       IS_64BIT=
>> +       has_config PPC64 && IS_64BIT=64
>> +       if has_config PPC_85xx; then
>> +               QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
>> +       elif has_config PPC_PSERIES; then
>> +               QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
>> +               SERIAL=hvc0
>> +               SERIAL_KCONFIG=HVC_CONSOLE
>> +       elif has_config PPC_PMAC; then
>> +               has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
>> +               SERIAL_KCONFIG=SERIAL_PMACZILOG
>> +       else
>> +               echo "Unknown PPC board" >&2
>> +               exit 1
>> +       fi
>> +
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
>> +       ;;
>> +esac
>> +
>> +if [ ! -e "$QEMU_BIN" ]; then
>> +       echo "\
>> +Could not find a usable QEMU binary. Please install one from \
>> +your distro or from source code using:
>> +
>> +  $ git clone git://git.qemu.org/qemu.git
>> +  $ cd qemu
>> +  $ ./configure
>> +  $ make -j
>> +  $ sudo make install
>> +" >&2
>> +       exit 1
>> +fi
>> +
>> +# The binaries without kvm in their name can be too old to support KVM, so
>> +# check for that before the user gets confused
>> +if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
>> +     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
>> +       echo "Your QEMU binary is too old, please update to at least 0.15." >&2
>> +       exit 1
>> +fi
>> +QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
>> +
>> +# We need to check some .config variables to make sure we actually work
>> +# on the respective kernel.
>> +if [ ! -e .config ]; then
>> +       echo "\
>> +Please run this script on a fully compiled and configured
>> +Linux kernel build directory" >&2
>> +       exit 1
>> +fi
>> +
>> +if [ ! -e "$KERNEL_BIN" ]; then
>> +       echo "Could not find kernel binary: $KERNEL_BIN" >&2
>> +       exit 1
>> +fi
>> +
>> +QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
>> +
>> +if [ "$USE_SDL" ]; then
>> +       # SDL is the default, so nothing to do
>> +       :
>> +elif [ "$USE_VNC" ]; then
>> +       QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
>> +else
>> +       # When emulating a serial console, tell the kernel to use it as well
>> +       QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
>> +       KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
>> +       MON_STDIO=1
>> +       require_config "$SERIAL_KCONFIG"
>> +fi
>> +
>> +if [ "$ROOTFS" ]; then
>> +       # Using rootfs with 9p
>> +       require_config "NET_9P_VIRTIO"
>> +       KERNEL_APPEND="$KERNEL_APPEND \
>> +root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
>> +
>> +#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
>> +
>> +
>> +       QEMU_OPTIONS="$QEMU_OPTIONS \
>> +-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
>> +-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
>> +fi
>> +
>> +[ "$SMP" ] || SMP=1
>> +
>> +# User append args come last
>> +KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
>> +
>> +############### Execution #################
>> +
>> +QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
>> +
>> +echo "
>> +       ################# Linux QEMU launcher #################
>> +
>> +This script executes your currently built Linux kernel using QEMU. If KVM is
>> +available, it will also use KVM for fast virtualization of your guest.
>> +
>> +The intent is to make it very easy to run your kernel. If you need to do more
>> +advanced things, such as passing through real devices, please use QEMU command
>> +line options and add them to the $BASENAME command line using --.
>> +
>> +This tool is for simplicity, not world dominating functionality coverage.
>> +(just a hobby, won't be big and professional like libvirt)
>> +
>> +"
>> +
>> +if [ "$MON_STDIO" ]; then
>> +       echo "\
>> +### Your guest is bound to the current foreground shell. To quit the guest, ###
>> +### please use Ctrl-A x                                                     ###
>> +"
>> +fi
>> +
>> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""
> 
> This line does not match [1] below.
> 
>> +echo
>> +
>> +GDB_PID=
>> +if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
>> +       # Run a gdb console in parallel to the kernel
>> +
>> +       # XXX find out if port is in use
>> +       PORT=$$
> 
> $$ could be <1024.

Yup. Fixed. It can still overflow, but let's hope that doesn't happen :(. We need a bit more logic here if we get more than 32k PIDs (plus, ports could be busy). Maybe we should listen on a UNIX socket?

> 
>> +       xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
> 
> But the gnomes might not have xterms but instead gterms and so on.
> Then there are wrappers like x-terminal-emulator on some distros.

Yeah, but that's Debian only FWIW. I don't think there's a good way of determining which terminal people have available and xterm should be easily installable by everyone and does the job. So I nailed it down to that for now.

However if you find a nicer way, please let me know!

> 
>> +       GDB_PID=$!
>> +       QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
>> +fi
>> +
>> +$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
> 
> [1]

Alrighty, fixed :).


Alex

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 25.08.2011, at 11:01, Blue Swirl wrote:

> On Wed, Aug 24, 2011 at 9:38 PM, Alexander Graf <agraf@suse.de> wrote:
>> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
>> would be doing and what he expects from it. Basically he wants a
>> small and simple tool he and other developers can run to try out and
>> see if the kernel they just built actually works.
>> 
>> Fortunately, QEMU can do that today already! The only piece that was
>> missing was the "simple" piece of the equation, so here is a script
>> that wraps around QEMU and executes a kernel you just built.
>> 
>> If you do have KVM around and are not cross-compiling, it will use
>> KVM. But if you don't, you can still fall back to emulation mode and
>> at least check if your kernel still does what you expect. I only
>> implemented support for s390x and ppc there, but it's easily extensible
>> to more platforms, as QEMU can emulate (and virtualize) pretty much
>> any platform out there.
>> 
>> If you don't have qemu installed, please do so before using this script. Your
>> distro should provide a package for it (might even call it "kvm"). If not,
>> just compile it from source - it's not hard!
>> 
>> To quickly get going, just execute the following as user:
>> 
>>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>> 
>> This will drop you into a shell on your rootfs.
>> 
>> Happy hacking!
>> 
>> Signed-off-by: Alexander Graf <agraf@suse.de>
>> 
>> ---
>> 
>> v1 -> v2:
>> 
>>  - fix naming of QEMU
>>  - use grep -q for has_config
>>  - support multiple -a args
>>  - spawn gdb on execution
>>  - pass through qemu options
>>  - dont use qemu-system-x86_64 on i386
>>  - add funny sentence to startup text
>>  - more helpful error messages
>> ---
>>  scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 files changed, 334 insertions(+), 0 deletions(-)
>>  create mode 100755 scripts/run-qemu.sh
>> 
>> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
>> new file mode 100755
>> index 0000000..5d4e185
>> --- /dev/null
>> +++ b/scripts/run-qemu.sh
>> @@ -0,0 +1,334 @@
>> +#!/bin/bash
>> +#
>> +# QEMU Launcher
>> +#
>> +# This script enables simple use of the KVM and QEMU tool stack for
>> +# easy kernel testing. It allows to pass either a host directory to
>> +# the guest or a disk image. Example usage:
>> +#
>> +# Run the host root fs inside a VM:
>> +#
>> +# $ ./scripts/run-qemu.sh -r /
>> +#
>> +# Run the same with SDL:
>> +#
>> +# $ ./scripts/run-qemu.sh -r / --sdl
>> +#
>> +# Or with a PPC build:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +#
>> +# PPC with a mac99 model by passing options to QEMU:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +#
>> +
>> +USE_SDL=
>> +USE_VNC=
>> +USE_GDB=1
>> +KERNEL_BIN=arch/x86/boot/bzImage
>> +MON_STDIO=
>> +KERNEL_APPEND2=
>> +SERIAL=ttyS0
>> +SERIAL_KCONFIG=SERIAL_8250
>> +BASENAME=$(basename "$0")
>> +
>> +function usage() {
>> +       echo "
>> +$BASENAME allows you to execute a virtual machine with the Linux kernel
>> +that you just built. To only execute a simple VM, you can just run it
>> +on your root fs with \"-r / -a init=/bin/bash\"
>> +
>> +       -a, --append parameters
>> +               Append the given parameters to the kernel command line.
>> +
>> +       -d, --disk image
>> +               Add the image file as disk into the VM.
>> +
>> +       -D, --no-gdb
>> +               Don't run an xterm with gdb attached to the guest.
>> +
>> +       -r, --root directory
>> +               Use the specified directory as root directory inside the guest.
>> +
>> +       -s, --sdl
>> +               Enable SDL graphical output.
>> +
>> +       -S, --smp cpus
>> +               Set number of virtual CPUs.
>> +
>> +       -v, --vnc
>> +               Enable VNC graphical output.
>> +
>> +Examples:
>> +
>> +       Run the host root fs inside a VM:
>> +       $ ./scripts/run-qemu.sh -r /
>> +
>> +       Run the same with SDL:
>> +       $ ./scripts/run-qemu.sh -r / --sdl
>> +
>> +       Or with a PPC build:
>> +       $ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +
>> +       PPC with a mac99 model by passing options to QEMU:
>> +       $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +"
>> +}
>> +
>> +function require_config() {
>> +       if [ "$(grep CONFIG_$1=y .config)" ]; then
>> +               return
>> +       fi
>> +
>> +       echo "You need to enable CONFIG_$1 for run-qemu to work properly"
>> +       exit 1
>> +}
>> +
>> +function has_config() {
>> +       grep -q "CONFIG_$1=y" .config
>> +}
>> +
>> +function drive_if() {
>> +       if has_config VIRTIO_BLK; then
>> +               echo virtio
>> +       elif has_config ATA_PIIX; then
>> +               echo ide
>> +       else
>> +               echo "\
>> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
>> +enabled for block device assignment" >&2
>> +               exit 1
>> +       fi
>> +}
>> +
>> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
>> +       -n "$(basename \"$0\")" -- "$@"`
>> +
>> +if [ $? != 0 ]; then
>> +       echo "Terminating..." >&2
>> +       exit 1
>> +fi
>> +
>> +eval set -- "$GETOPT"
>> +
>> +while true; do
>> +       case "$1" in
>> +       -a|--append)
>> +               KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
>> +               shift
>> +               ;;
>> +       -d|--disk)
>> +               QEMU_OPTIONS="$QEMU_OPTIONS -drive \
>> +                       file=$2,if=$(drive_if),cache=unsafe"
>> +               USE_DISK=1
>> +               shift
>> +               ;;
>> +       -D|--no-gdb)
>> +               USE_GDB=
>> +               ;;
>> +       -h|--help)
>> +               usage
>> +               exit 0
>> +               ;;
>> +       -r|--root)
>> +               ROOTFS="$2"
>> +               shift
>> +               ;;
>> +       -s|--sdl)
>> +               USE_SDL=1
>> +               ;;
>> +       -S|--smp)
>> +               SMP="$2"
>> +               shift
>> +               ;;
>> +       -v|--vnc)
>> +               USE_VNC=1
>> +               ;;
>> +       --)
>> +               shift
>> +               break
>> +               ;;
>> +       *)
>> +               echo "Could not parse option: $1" >&2
>> +               exit 1
>> +               ;;
>> +       esac
>> +       shift
>> +done
>> +
>> +if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
>> +       echo "\
>> +Error: Please specify at least -r or -d with a target \
>> +FS to run off of" >&2
>> +       exit 1
>> +fi
>> +
>> +# Try to find the KVM accelerated QEMU binary
>> +
>> +[ "$ARCH" ] || ARCH=$(uname -m)
>> +case $ARCH in
>> +x86_64)
>> +       KERNEL_BIN=arch/x86/boot/bzImage
>> +       # SUSE and Red Hat call the binary qemu-kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
>> +
>> +       # Debian and Gentoo call it kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
>> +
>> +       # QEMU's own build system calls it qemu-system-x86_64
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
>> +       ;;
>> +i*86)
>> +       KERNEL_BIN=arch/x86/boot/bzImage
>> +       # SUSE and Red Hat call the binary qemu-kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
>> +
>> +       # Debian and Gentoo call it kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
>> +
>> +       KERNEL_BIN=arch/x86/boot/bzImage
>> +       # i386 version of QEMU
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
>> +       ;;
>> +s390*)
>> +       KERNEL_BIN=arch/s390/boot/image
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
>> +       ;;
>> +ppc*)
>> +       KERNEL_BIN=vmlinux
>> +
>> +       IS_64BIT=
>> +       has_config PPC64 && IS_64BIT=64
>> +       if has_config PPC_85xx; then
>> +               QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
>> +       elif has_config PPC_PSERIES; then
>> +               QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
>> +               SERIAL=hvc0
>> +               SERIAL_KCONFIG=HVC_CONSOLE
>> +       elif has_config PPC_PMAC; then
>> +               has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
>> +               SERIAL_KCONFIG=SERIAL_PMACZILOG
>> +       else
>> +               echo "Unknown PPC board" >&2
>> +               exit 1
>> +       fi
>> +
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
>> +       ;;
>> +esac
>> +
>> +if [ ! -e "$QEMU_BIN" ]; then
>> +       echo "\
>> +Could not find a usable QEMU binary. Please install one from \
>> +your distro or from source code using:
>> +
>> +  $ git clone git://git.qemu.org/qemu.git
>> +  $ cd qemu
>> +  $ ./configure
>> +  $ make -j
>> +  $ sudo make install
>> +" >&2
>> +       exit 1
>> +fi
>> +
>> +# The binaries without kvm in their name can be too old to support KVM, so
>> +# check for that before the user gets confused
>> +if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
>> +     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
>> +       echo "Your QEMU binary is too old, please update to at least 0.15." >&2
>> +       exit 1
>> +fi
>> +QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
>> +
>> +# We need to check some .config variables to make sure we actually work
>> +# on the respective kernel.
>> +if [ ! -e .config ]; then
>> +       echo "\
>> +Please run this script on a fully compiled and configured
>> +Linux kernel build directory" >&2
>> +       exit 1
>> +fi
>> +
>> +if [ ! -e "$KERNEL_BIN" ]; then
>> +       echo "Could not find kernel binary: $KERNEL_BIN" >&2
>> +       exit 1
>> +fi
>> +
>> +QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
>> +
>> +if [ "$USE_SDL" ]; then
>> +       # SDL is the default, so nothing to do
>> +       :
>> +elif [ "$USE_VNC" ]; then
>> +       QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
>> +else
>> +       # When emulating a serial console, tell the kernel to use it as well
>> +       QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
>> +       KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
>> +       MON_STDIO=1
>> +       require_config "$SERIAL_KCONFIG"
>> +fi
>> +
>> +if [ "$ROOTFS" ]; then
>> +       # Using rootfs with 9p
>> +       require_config "NET_9P_VIRTIO"
>> +       KERNEL_APPEND="$KERNEL_APPEND \
>> +root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
>> +
>> +#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
>> +
>> +
>> +       QEMU_OPTIONS="$QEMU_OPTIONS \
>> +-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
>> +-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
>> +fi
>> +
>> +[ "$SMP" ] || SMP=1
>> +
>> +# User append args come last
>> +KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
>> +
>> +############### Execution #################
>> +
>> +QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
>> +
>> +echo "
>> +       ################# Linux QEMU launcher #################
>> +
>> +This script executes your currently built Linux kernel using QEMU. If KVM is
>> +available, it will also use KVM for fast virtualization of your guest.
>> +
>> +The intent is to make it very easy to run your kernel. If you need to do more
>> +advanced things, such as passing through real devices, please use QEMU command
>> +line options and add them to the $BASENAME command line using --.
>> +
>> +This tool is for simplicity, not world dominating functionality coverage.
>> +(just a hobby, won't be big and professional like libvirt)
>> +
>> +"
>> +
>> +if [ "$MON_STDIO" ]; then
>> +       echo "\
>> +### Your guest is bound to the current foreground shell. To quit the guest, ###
>> +### please use Ctrl-A x                                                     ###
>> +"
>> +fi
>> +
>> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""
> 
> This line does not match [1] below.
> 
>> +echo
>> +
>> +GDB_PID=
>> +if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
>> +       # Run a gdb console in parallel to the kernel
>> +
>> +       # XXX find out if port is in use
>> +       PORT=$$
> 
> $$ could be <1024.

Yup. Fixed. It can still overflow, but let's hope that doesn't happen :(. We need a bit more logic here if we get more than 32k PIDs (plus, ports could be busy). Maybe we should listen on a UNIX socket?

> 
>> +       xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
> 
> But the gnomes might not have xterms but instead gterms and so on.
> Then there are wrappers like x-terminal-emulator on some distros.

Yeah, but that's Debian only FWIW. I don't think there's a good way of determining which terminal people have available and xterm should be easily installable by everyone and does the job. So I nailed it down to that for now.

However if you find a nicer way, please let me know!

> 
>> +       GDB_PID=$!
>> +       QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
>> +fi
>> +
>> +$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
> 
> [1]

Alrighty, fixed :).


Alex

Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 25.08.2011, at 11:01, Blue Swirl wrote:

> On Wed, Aug 24, 2011 at 9:38 PM, Alexander Graf <agraf@suse.de> wrote:
>> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
>> would be doing and what he expects from it. Basically he wants a
>> small and simple tool he and other developers can run to try out and
>> see if the kernel they just built actually works.
>> 
>> Fortunately, QEMU can do that today already! The only piece that was
>> missing was the "simple" piece of the equation, so here is a script
>> that wraps around QEMU and executes a kernel you just built.
>> 
>> If you do have KVM around and are not cross-compiling, it will use
>> KVM. But if you don't, you can still fall back to emulation mode and
>> at least check if your kernel still does what you expect. I only
>> implemented support for s390x and ppc there, but it's easily extensible
>> to more platforms, as QEMU can emulate (and virtualize) pretty much
>> any platform out there.
>> 
>> If you don't have qemu installed, please do so before using this script. Your
>> distro should provide a package for it (might even call it "kvm"). If not,
>> just compile it from source - it's not hard!
>> 
>> To quickly get going, just execute the following as user:
>> 
>>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>> 
>> This will drop you into a shell on your rootfs.
>> 
>> Happy hacking!
>> 
>> Signed-off-by: Alexander Graf <agraf@suse.de>
>> 
>> ---
>> 
>> v1 -> v2:
>> 
>>  - fix naming of QEMU
>>  - use grep -q for has_config
>>  - support multiple -a args
>>  - spawn gdb on execution
>>  - pass through qemu options
>>  - dont use qemu-system-x86_64 on i386
>>  - add funny sentence to startup text
>>  - more helpful error messages
>> ---
>>  scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 files changed, 334 insertions(+), 0 deletions(-)
>>  create mode 100755 scripts/run-qemu.sh
>> 
>> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
>> new file mode 100755
>> index 0000000..5d4e185
>> --- /dev/null
>> +++ b/scripts/run-qemu.sh
>> @@ -0,0 +1,334 @@
>> +#!/bin/bash
>> +#
>> +# QEMU Launcher
>> +#
>> +# This script enables simple use of the KVM and QEMU tool stack for
>> +# easy kernel testing. It allows to pass either a host directory to
>> +# the guest or a disk image. Example usage:
>> +#
>> +# Run the host root fs inside a VM:
>> +#
>> +# $ ./scripts/run-qemu.sh -r /
>> +#
>> +# Run the same with SDL:
>> +#
>> +# $ ./scripts/run-qemu.sh -r / --sdl
>> +#
>> +# Or with a PPC build:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +#
>> +# PPC with a mac99 model by passing options to QEMU:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +#
>> +
>> +USE_SDL=
>> +USE_VNC=
>> +USE_GDB=1
>> +KERNEL_BIN=arch/x86/boot/bzImage
>> +MON_STDIO=
>> +KERNEL_APPEND2=
>> +SERIAL=ttyS0
>> +SERIAL_KCONFIG=SERIAL_8250
>> +BASENAME=$(basename "$0")
>> +
>> +function usage() {
>> +       echo "
>> +$BASENAME allows you to execute a virtual machine with the Linux kernel
>> +that you just built. To only execute a simple VM, you can just run it
>> +on your root fs with \"-r / -a init=/bin/bash\"
>> +
>> +       -a, --append parameters
>> +               Append the given parameters to the kernel command line.
>> +
>> +       -d, --disk image
>> +               Add the image file as disk into the VM.
>> +
>> +       -D, --no-gdb
>> +               Don't run an xterm with gdb attached to the guest.
>> +
>> +       -r, --root directory
>> +               Use the specified directory as root directory inside the guest.
>> +
>> +       -s, --sdl
>> +               Enable SDL graphical output.
>> +
>> +       -S, --smp cpus
>> +               Set number of virtual CPUs.
>> +
>> +       -v, --vnc
>> +               Enable VNC graphical output.
>> +
>> +Examples:
>> +
>> +       Run the host root fs inside a VM:
>> +       $ ./scripts/run-qemu.sh -r /
>> +
>> +       Run the same with SDL:
>> +       $ ./scripts/run-qemu.sh -r / --sdl
>> +
>> +       Or with a PPC build:
>> +       $ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +
>> +       PPC with a mac99 model by passing options to QEMU:
>> +       $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +"
>> +}
>> +
>> +function require_config() {
>> +       if [ "$(grep CONFIG_$1=y .config)" ]; then
>> +               return
>> +       fi
>> +
>> +       echo "You need to enable CONFIG_$1 for run-qemu to work properly"
>> +       exit 1
>> +}
>> +
>> +function has_config() {
>> +       grep -q "CONFIG_$1=y" .config
>> +}
>> +
>> +function drive_if() {
>> +       if has_config VIRTIO_BLK; then
>> +               echo virtio
>> +       elif has_config ATA_PIIX; then
>> +               echo ide
>> +       else
>> +               echo "\
>> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
>> +enabled for block device assignment" >&2
>> +               exit 1
>> +       fi
>> +}
>> +
>> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
>> +       -n "$(basename \"$0\")" -- "$@"`
>> +
>> +if [ $? != 0 ]; then
>> +       echo "Terminating..." >&2
>> +       exit 1
>> +fi
>> +
>> +eval set -- "$GETOPT"
>> +
>> +while true; do
>> +       case "$1" in
>> +       -a|--append)
>> +               KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
>> +               shift
>> +               ;;
>> +       -d|--disk)
>> +               QEMU_OPTIONS="$QEMU_OPTIONS -drive \
>> +                       file=$2,if=$(drive_if),cache=unsafe"
>> +               USE_DISK=1
>> +               shift
>> +               ;;
>> +       -D|--no-gdb)
>> +               USE_GDB=
>> +               ;;
>> +       -h|--help)
>> +               usage
>> +               exit 0
>> +               ;;
>> +       -r|--root)
>> +               ROOTFS="$2"
>> +               shift
>> +               ;;
>> +       -s|--sdl)
>> +               USE_SDL=1
>> +               ;;
>> +       -S|--smp)
>> +               SMP="$2"
>> +               shift
>> +               ;;
>> +       -v|--vnc)
>> +               USE_VNC=1
>> +               ;;
>> +       --)
>> +               shift
>> +               break
>> +               ;;
>> +       *)
>> +               echo "Could not parse option: $1" >&2
>> +               exit 1
>> +               ;;
>> +       esac
>> +       shift
>> +done
>> +
>> +if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
>> +       echo "\
>> +Error: Please specify at least -r or -d with a target \
>> +FS to run off of" >&2
>> +       exit 1
>> +fi
>> +
>> +# Try to find the KVM accelerated QEMU binary
>> +
>> +[ "$ARCH" ] || ARCH=$(uname -m)
>> +case $ARCH in
>> +x86_64)
>> +       KERNEL_BIN=arch/x86/boot/bzImage
>> +       # SUSE and Red Hat call the binary qemu-kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
>> +
>> +       # Debian and Gentoo call it kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
>> +
>> +       # QEMU's own build system calls it qemu-system-x86_64
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
>> +       ;;
>> +i*86)
>> +       KERNEL_BIN=arch/x86/boot/bzImage
>> +       # SUSE and Red Hat call the binary qemu-kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
>> +
>> +       # Debian and Gentoo call it kvm
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
>> +
>> +       KERNEL_BIN=arch/x86/boot/bzImage
>> +       # i386 version of QEMU
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
>> +       ;;
>> +s390*)
>> +       KERNEL_BIN=arch/s390/boot/image
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
>> +       ;;
>> +ppc*)
>> +       KERNEL_BIN=vmlinux
>> +
>> +       IS_64BIT=
>> +       has_config PPC64 && IS_64BIT=64
>> +       if has_config PPC_85xx; then
>> +               QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
>> +       elif has_config PPC_PSERIES; then
>> +               QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
>> +               SERIAL=hvc0
>> +               SERIAL_KCONFIG=HVC_CONSOLE
>> +       elif has_config PPC_PMAC; then
>> +               has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
>> +               SERIAL_KCONFIG=SERIAL_PMACZILOG
>> +       else
>> +               echo "Unknown PPC board" >&2
>> +               exit 1
>> +       fi
>> +
>> +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
>> +       ;;
>> +esac
>> +
>> +if [ ! -e "$QEMU_BIN" ]; then
>> +       echo "\
>> +Could not find a usable QEMU binary. Please install one from \
>> +your distro or from source code using:
>> +
>> +  $ git clone git://git.qemu.org/qemu.git
>> +  $ cd qemu
>> +  $ ./configure
>> +  $ make -j
>> +  $ sudo make install
>> +" >&2
>> +       exit 1
>> +fi
>> +
>> +# The binaries without kvm in their name can be too old to support KVM, so
>> +# check for that before the user gets confused
>> +if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
>> +     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
>> +       echo "Your QEMU binary is too old, please update to at least 0.15." >&2
>> +       exit 1
>> +fi
>> +QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
>> +
>> +# We need to check some .config variables to make sure we actually work
>> +# on the respective kernel.
>> +if [ ! -e .config ]; then
>> +       echo "\
>> +Please run this script on a fully compiled and configured
>> +Linux kernel build directory" >&2
>> +       exit 1
>> +fi
>> +
>> +if [ ! -e "$KERNEL_BIN" ]; then
>> +       echo "Could not find kernel binary: $KERNEL_BIN" >&2
>> +       exit 1
>> +fi
>> +
>> +QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
>> +
>> +if [ "$USE_SDL" ]; then
>> +       # SDL is the default, so nothing to do
>> +       :
>> +elif [ "$USE_VNC" ]; then
>> +       QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
>> +else
>> +       # When emulating a serial console, tell the kernel to use it as well
>> +       QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
>> +       KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
>> +       MON_STDIO=1
>> +       require_config "$SERIAL_KCONFIG"
>> +fi
>> +
>> +if [ "$ROOTFS" ]; then
>> +       # Using rootfs with 9p
>> +       require_config "NET_9P_VIRTIO"
>> +       KERNEL_APPEND="$KERNEL_APPEND \
>> +root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
>> +
>> +#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
>> +
>> +
>> +       QEMU_OPTIONS="$QEMU_OPTIONS \
>> +-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
>> +-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
>> +fi
>> +
>> +[ "$SMP" ] || SMP=1
>> +
>> +# User append args come last
>> +KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
>> +
>> +############### Execution #################
>> +
>> +QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
>> +
>> +echo "
>> +       ################# Linux QEMU launcher #################
>> +
>> +This script executes your currently built Linux kernel using QEMU. If KVM is
>> +available, it will also use KVM for fast virtualization of your guest.
>> +
>> +The intent is to make it very easy to run your kernel. If you need to do more
>> +advanced things, such as passing through real devices, please use QEMU command
>> +line options and add them to the $BASENAME command line using --.
>> +
>> +This tool is for simplicity, not world dominating functionality coverage.
>> +(just a hobby, won't be big and professional like libvirt)
>> +
>> +"
>> +
>> +if [ "$MON_STDIO" ]; then
>> +       echo "\
>> +### Your guest is bound to the current foreground shell. To quit the guest, ###
>> +### please use Ctrl-A x                                                     ###
>> +"
>> +fi
>> +
>> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""
> 
> This line does not match [1] below.
> 
>> +echo
>> +
>> +GDB_PID=
>> +if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
>> +       # Run a gdb console in parallel to the kernel
>> +
>> +       # XXX find out if port is in use
>> +       PORT=$$
> 
> $$ could be <1024.

Yup. Fixed. It can still overflow, but let's hope that doesn't happen :(. We need a bit more logic here if we get more than 32k PIDs (plus, ports could be busy). Maybe we should listen on a UNIX socket?

> 
>> +       xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
> 
> But the gnomes might not have xterms but instead gterms and so on.
> Then there are wrappers like x-terminal-emulator on some distros.

Yeah, but that's Debian only FWIW. I don't think there's a good way of determining which terminal people have available and xterm should be easily installable by everyone and does the job. So I nailed it down to that for now.

However if you find a nicer way, please let me know!

> 
>> +       GDB_PID=$!
>> +       QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
>> +fi
>> +
>> +$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
> 
> [1]

Alrighty, fixed :).


Alex

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

[-- Attachment #1: Type: text/plain, Size: 11644 bytes --]

On 2011-08-24 23:38, Alexander Graf wrote:
> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> would be doing and what he expects from it. Basically he wants a
> small and simple tool he and other developers can run to try out and
> see if the kernel they just built actually works.
> 
> Fortunately, QEMU can do that today already! The only piece that was
> missing was the "simple" piece of the equation, so here is a script
> that wraps around QEMU and executes a kernel you just built.
> 
> If you do have KVM around and are not cross-compiling, it will use
> KVM. But if you don't, you can still fall back to emulation mode and
> at least check if your kernel still does what you expect. I only
> implemented support for s390x and ppc there, but it's easily extensible
> to more platforms, as QEMU can emulate (and virtualize) pretty much
> any platform out there.
> 
> If you don't have qemu installed, please do so before using this script. Your
> distro should provide a package for it (might even call it "kvm"). If not,
> just compile it from source - it's not hard!
> 
> To quickly get going, just execute the following as user:
> 
>     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
> 
> This will drop you into a shell on your rootfs.
> 
> Happy hacking!
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> 
> ---
> 
> v1 -> v2:
> 
>   - fix naming of QEMU
>   - use grep -q for has_config
>   - support multiple -a args
>   - spawn gdb on execution
>   - pass through qemu options
>   - dont use qemu-system-x86_64 on i386
>   - add funny sentence to startup text
>   - more helpful error messages
> ---
>  scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 334 insertions(+), 0 deletions(-)
>  create mode 100755 scripts/run-qemu.sh
> 
> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
> new file mode 100755
> index 0000000..5d4e185
> --- /dev/null
> +++ b/scripts/run-qemu.sh
> @@ -0,0 +1,334 @@
> +#!/bin/bash
> +#
> +# QEMU Launcher
> +#
> +# This script enables simple use of the KVM and QEMU tool stack for
> +# easy kernel testing. It allows to pass either a host directory to
> +# the guest or a disk image. Example usage:
> +#
> +# Run the host root fs inside a VM:
> +#
> +# $ ./scripts/run-qemu.sh -r /
> +#
> +# Run the same with SDL:
> +#
> +# $ ./scripts/run-qemu.sh -r / --sdl
> +# 
> +# Or with a PPC build:
> +#
> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
> +# 
> +# PPC with a mac99 model by passing options to QEMU:
> +#
> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
> +#
> +
> +USE_SDL=
> +USE_VNC=
> +USE_GDB=1
> +KERNEL_BIN=arch/x86/boot/bzImage
> +MON_STDIO=
> +KERNEL_APPEND2=
> +SERIAL=ttyS0
> +SERIAL_KCONFIG=SERIAL_8250
> +BASENAME=$(basename "$0")
> +
> +function usage() {
> +	echo "
> +$BASENAME allows you to execute a virtual machine with the Linux kernel
> +that you just built. To only execute a simple VM, you can just run it
> +on your root fs with \"-r / -a init=/bin/bash\"
> +
> +	-a, --append parameters
> +		Append the given parameters to the kernel command line.
> +
> +	-d, --disk image
> +		Add the image file as disk into the VM.
> +
> +	-D, --no-gdb
> +		Don't run an xterm with gdb attached to the guest.
> +
> +	-r, --root directory
> +		Use the specified directory as root directory inside the guest.
> +
> +	-s, --sdl
> +		Enable SDL graphical output.
> +
> +	-S, --smp cpus
> +		Set number of virtual CPUs.
> +
> +	-v, --vnc
> +		Enable VNC graphical output.
> +
> +Examples:
> +
> +	Run the host root fs inside a VM:
> +	$ ./scripts/run-qemu.sh -r /
> +
> +	Run the same with SDL:
> +	$ ./scripts/run-qemu.sh -r / --sdl
> +	
> +	Or with a PPC build:
> +	$ ARCH=ppc ./scripts/run-qemu.sh -r /
> +	
> +	PPC with a mac99 model by passing options to QEMU:
> +	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
> +"
> +}
> +
> +function require_config() {
> +	if [ "$(grep CONFIG_$1=y .config)" ]; then
> +		return
> +	fi
> +
> +	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
> +	exit 1
> +}
> +
> +function has_config() {
> +	grep -q "CONFIG_$1=y" .config
> +}
> +
> +function drive_if() {
> +	if has_config VIRTIO_BLK; then
> +		echo virtio
> +	elif has_config ATA_PIIX; then
> +		echo ide

+ require_config "BLK_DEV_SD"

Maybe there should also be a warning if no standard FS (ext[34], btrfs,
xfs etc.) is build into the kernel.

Another thing, but that's just a recommendation for initrd-free mode:
DEVTMPFS_MOUNT

> +	else
> +		echo "\
> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
> +enabled for block device assignment" >&2
> +		exit 1
> +	fi
> +}
> +
> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
> +	-n "$(basename \"$0\")" -- "$@"`
> +
> +if [ $? != 0 ]; then
> +	echo "Terminating..." >&2
> +	exit 1
> +fi
> +
> +eval set -- "$GETOPT"
> +
> +while true; do
> +	case "$1" in
> +	-a|--append)
> +		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"

That should be

KERNEL_APPEND2="$KERNEL_APPEND2 $2"

> +		shift
> +		;;
> +	-d|--disk)
> +		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
> +			file=$2,if=$(drive_if),cache=unsafe"

		if [ $? != 0 ]; then
			exit $?
		fi

> +		USE_DISK=1
> +		shift
> +		;;
> +	-D|--no-gdb)
> +		USE_GDB=
> +		;;
> +	-h|--help)
> +		usage
> +		exit 0
> +		;;
> +	-r|--root)
> +		ROOTFS="$2"
> +		shift
> +		;;
> +	-s|--sdl)
> +		USE_SDL=1
> +		;;
> +	-S|--smp)
> +		SMP="$2"
> +		shift
> +		;;
> +	-v|--vnc)
> +		USE_VNC=1
> +		;;
> +	--)
> +		shift
> +		break
> +		;;
> +	*)
> +		echo "Could not parse option: $1" >&2
> +		exit 1
> +		;;
> +	esac
> +	shift
> +done
> +
> +if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
> +	echo "\
> +Error: Please specify at least -r or -d with a target \
> +FS to run off of" >&2
> +	exit 1
> +fi
> +
> +# Try to find the KVM accelerated QEMU binary
> +
> +[ "$ARCH" ] || ARCH=$(uname -m)
> +case $ARCH in
> +x86_64)
> +	KERNEL_BIN=arch/x86/boot/bzImage
> +	# SUSE and Red Hat call the binary qemu-kvm
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
> +
> +	# Debian and Gentoo call it kvm
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
> +
> +	# QEMU's own build system calls it qemu-system-x86_64
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
> +	;;
> +i*86)
> +	KERNEL_BIN=arch/x86/boot/bzImage
> +	# SUSE and Red Hat call the binary qemu-kvm
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
> +
> +	# Debian and Gentoo call it kvm
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
> +
> +	KERNEL_BIN=arch/x86/boot/bzImage
> +	# i386 version of QEMU
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
> +	;;
> +s390*)
> +	KERNEL_BIN=arch/s390/boot/image
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
> +	;;
> +ppc*)
> +	KERNEL_BIN=vmlinux
> +
> +	IS_64BIT=
> +	has_config PPC64 && IS_64BIT=64
> +	if has_config PPC_85xx; then
> +		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
> +	elif has_config PPC_PSERIES; then
> +		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
> +		SERIAL=hvc0
> +		SERIAL_KCONFIG=HVC_CONSOLE
> +	elif has_config PPC_PMAC; then
> +		has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
> +		SERIAL_KCONFIG=SERIAL_PMACZILOG
> +	else
> +		echo "Unknown PPC board" >&2
> +		exit 1
> +	fi
> +
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
> +	;;
> +esac
> +
> +if [ ! -e "$QEMU_BIN" ]; then
> +	echo "\
> +Could not find a usable QEMU binary. Please install one from \
> +your distro or from source code using:
> +
> +  $ git clone git://git.qemu.org/qemu.git
> +  $ cd qemu
> +  $ ./configure
> +  $ make -j
> +  $ sudo make install
> +" >&2
> +	exit 1
> +fi
> +
> +# The binaries without kvm in their name can be too old to support KVM, so
> +# check for that before the user gets confused
> +if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
> +     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
> +	echo "Your QEMU binary is too old, please update to at least 0.15." >&2
> +	exit 1
> +fi
> +QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
> +
> +# We need to check some .config variables to make sure we actually work
> +# on the respective kernel.
> +if [ ! -e .config ]; then
> +	echo "\
> +Please run this script on a fully compiled and configured
> +Linux kernel build directory" >&2
> +	exit 1
> +fi
> +
> +if [ ! -e "$KERNEL_BIN" ]; then
> +	echo "Could not find kernel binary: $KERNEL_BIN" >&2
> +	exit 1
> +fi
> +
> +QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
> +
> +if [ "$USE_SDL" ]; then
> +	# SDL is the default, so nothing to do
> +	:
> +elif [ "$USE_VNC" ]; then
> +	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
> +else
> +	# When emulating a serial console, tell the kernel to use it as well
> +	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
> +	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
> +	MON_STDIO=1
> +	require_config "$SERIAL_KCONFIG"
> +fi
> +
> +if [ "$ROOTFS" ]; then
> +	# Using rootfs with 9p
> +	require_config "NET_9P_VIRTIO"

+ require_config "9P_FS"

> +	KERNEL_APPEND="$KERNEL_APPEND \
> +root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
> +
> +#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
> +
> +
> +	QEMU_OPTIONS="$QEMU_OPTIONS \
> +-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
> +-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
> +fi
> +
> +[ "$SMP" ] || SMP=1
> +
> +# User append args come last
> +KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
> +
> +############### Execution #################
> +
> +QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
> +
> +echo "
> +	################# Linux QEMU launcher #################
> +
> +This script executes your currently built Linux kernel using QEMU. If KVM is
> +available, it will also use KVM for fast virtualization of your guest.
> +
> +The intent is to make it very easy to run your kernel. If you need to do more
> +advanced things, such as passing through real devices, please use QEMU command
> +line options and add them to the $BASENAME command line using --.
> +
> +This tool is for simplicity, not world dominating functionality coverage.
> +(just a hobby, won't be big and professional like libvirt)
> +
> +"
> +
> +if [ "$MON_STDIO" ]; then
> +	echo "\
> +### Your guest is bound to the current foreground shell. To quit the guest, ###
> +### please use Ctrl-A x                                                     ###
> +"
> +fi
> +
> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""
> +echo
> +
> +GDB_PID=
> +if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
> +	# Run a gdb console in parallel to the kernel
> +
> +	# XXX find out if port is in use
> +	PORT=$$
> +	xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
> +	GDB_PID=$!
> +	QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
> +fi
> +
> +$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
> +wait $GDB_PID &>/dev/null
> +

Nice that it forks off a gdb session. I will contribute my gdb helper
script soon (module symbol loading, dmesg, per-cpu variable lookup etc.)
so that it can be loaded automatically.

Jan


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Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

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On 2011-08-24 23:38, Alexander Graf wrote:
> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> would be doing and what he expects from it. Basically he wants a
> small and simple tool he and other developers can run to try out and
> see if the kernel they just built actually works.
> 
> Fortunately, QEMU can do that today already! The only piece that was
> missing was the "simple" piece of the equation, so here is a script
> that wraps around QEMU and executes a kernel you just built.
> 
> If you do have KVM around and are not cross-compiling, it will use
> KVM. But if you don't, you can still fall back to emulation mode and
> at least check if your kernel still does what you expect. I only
> implemented support for s390x and ppc there, but it's easily extensible
> to more platforms, as QEMU can emulate (and virtualize) pretty much
> any platform out there.
> 
> If you don't have qemu installed, please do so before using this script. Your
> distro should provide a package for it (might even call it "kvm"). If not,
> just compile it from source - it's not hard!
> 
> To quickly get going, just execute the following as user:
> 
>     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
> 
> This will drop you into a shell on your rootfs.
> 
> Happy hacking!
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> 
> ---
> 
> v1 -> v2:
> 
>   - fix naming of QEMU
>   - use grep -q for has_config
>   - support multiple -a args
>   - spawn gdb on execution
>   - pass through qemu options
>   - dont use qemu-system-x86_64 on i386
>   - add funny sentence to startup text
>   - more helpful error messages
> ---
>  scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 334 insertions(+), 0 deletions(-)
>  create mode 100755 scripts/run-qemu.sh
> 
> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
> new file mode 100755
> index 0000000..5d4e185
> --- /dev/null
> +++ b/scripts/run-qemu.sh
> @@ -0,0 +1,334 @@
> +#!/bin/bash
> +#
> +# QEMU Launcher
> +#
> +# This script enables simple use of the KVM and QEMU tool stack for
> +# easy kernel testing. It allows to pass either a host directory to
> +# the guest or a disk image. Example usage:
> +#
> +# Run the host root fs inside a VM:
> +#
> +# $ ./scripts/run-qemu.sh -r /
> +#
> +# Run the same with SDL:
> +#
> +# $ ./scripts/run-qemu.sh -r / --sdl
> +# 
> +# Or with a PPC build:
> +#
> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
> +# 
> +# PPC with a mac99 model by passing options to QEMU:
> +#
> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
> +#
> +
> +USE_SDL=
> +USE_VNC=
> +USE_GDB=1
> +KERNEL_BIN=arch/x86/boot/bzImage
> +MON_STDIO=
> +KERNEL_APPEND2=
> +SERIAL=ttyS0
> +SERIAL_KCONFIG=SERIAL_8250
> +BASENAME=$(basename "$0")
> +
> +function usage() {
> +	echo "
> +$BASENAME allows you to execute a virtual machine with the Linux kernel
> +that you just built. To only execute a simple VM, you can just run it
> +on your root fs with \"-r / -a init=/bin/bash\"
> +
> +	-a, --append parameters
> +		Append the given parameters to the kernel command line.
> +
> +	-d, --disk image
> +		Add the image file as disk into the VM.
> +
> +	-D, --no-gdb
> +		Don't run an xterm with gdb attached to the guest.
> +
> +	-r, --root directory
> +		Use the specified directory as root directory inside the guest.
> +
> +	-s, --sdl
> +		Enable SDL graphical output.
> +
> +	-S, --smp cpus
> +		Set number of virtual CPUs.
> +
> +	-v, --vnc
> +		Enable VNC graphical output.
> +
> +Examples:
> +
> +	Run the host root fs inside a VM:
> +	$ ./scripts/run-qemu.sh -r /
> +
> +	Run the same with SDL:
> +	$ ./scripts/run-qemu.sh -r / --sdl
> +	
> +	Or with a PPC build:
> +	$ ARCH=ppc ./scripts/run-qemu.sh -r /
> +	
> +	PPC with a mac99 model by passing options to QEMU:
> +	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
> +"
> +}
> +
> +function require_config() {
> +	if [ "$(grep CONFIG_$1=y .config)" ]; then
> +		return
> +	fi
> +
> +	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
> +	exit 1
> +}
> +
> +function has_config() {
> +	grep -q "CONFIG_$1=y" .config
> +}
> +
> +function drive_if() {
> +	if has_config VIRTIO_BLK; then
> +		echo virtio
> +	elif has_config ATA_PIIX; then
> +		echo ide

+ require_config "BLK_DEV_SD"

Maybe there should also be a warning if no standard FS (ext[34], btrfs,
xfs etc.) is build into the kernel.

Another thing, but that's just a recommendation for initrd-free mode:
DEVTMPFS_MOUNT

> +	else
> +		echo "\
> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
> +enabled for block device assignment" >&2
> +		exit 1
> +	fi
> +}
> +
> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
> +	-n "$(basename \"$0\")" -- "$@"`
> +
> +if [ $? != 0 ]; then
> +	echo "Terminating..." >&2
> +	exit 1
> +fi
> +
> +eval set -- "$GETOPT"
> +
> +while true; do
> +	case "$1" in
> +	-a|--append)
> +		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"

That should be

KERNEL_APPEND2="$KERNEL_APPEND2 $2"

> +		shift
> +		;;
> +	-d|--disk)
> +		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
> +			file=$2,if=$(drive_if),cache=unsafe"

		if [ $? != 0 ]; then
			exit $?
		fi

> +		USE_DISK=1
> +		shift
> +		;;
> +	-D|--no-gdb)
> +		USE_GDB=
> +		;;
> +	-h|--help)
> +		usage
> +		exit 0
> +		;;
> +	-r|--root)
> +		ROOTFS="$2"
> +		shift
> +		;;
> +	-s|--sdl)
> +		USE_SDL=1
> +		;;
> +	-S|--smp)
> +		SMP="$2"
> +		shift
> +		;;
> +	-v|--vnc)
> +		USE_VNC=1
> +		;;
> +	--)
> +		shift
> +		break
> +		;;
> +	*)
> +		echo "Could not parse option: $1" >&2
> +		exit 1
> +		;;
> +	esac
> +	shift
> +done
> +
> +if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
> +	echo "\
> +Error: Please specify at least -r or -d with a target \
> +FS to run off of" >&2
> +	exit 1
> +fi
> +
> +# Try to find the KVM accelerated QEMU binary
> +
> +[ "$ARCH" ] || ARCH=$(uname -m)
> +case $ARCH in
> +x86_64)
> +	KERNEL_BIN=arch/x86/boot/bzImage
> +	# SUSE and Red Hat call the binary qemu-kvm
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
> +
> +	# Debian and Gentoo call it kvm
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
> +
> +	# QEMU's own build system calls it qemu-system-x86_64
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
> +	;;
> +i*86)
> +	KERNEL_BIN=arch/x86/boot/bzImage
> +	# SUSE and Red Hat call the binary qemu-kvm
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
> +
> +	# Debian and Gentoo call it kvm
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
> +
> +	KERNEL_BIN=arch/x86/boot/bzImage
> +	# i386 version of QEMU
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
> +	;;
> +s390*)
> +	KERNEL_BIN=arch/s390/boot/image
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
> +	;;
> +ppc*)
> +	KERNEL_BIN=vmlinux
> +
> +	IS_64BIT=
> +	has_config PPC64 && IS_64BIT=64
> +	if has_config PPC_85xx; then
> +		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
> +	elif has_config PPC_PSERIES; then
> +		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
> +		SERIAL=hvc0
> +		SERIAL_KCONFIG=HVC_CONSOLE
> +	elif has_config PPC_PMAC; then
> +		has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
> +		SERIAL_KCONFIG=SERIAL_PMACZILOG
> +	else
> +		echo "Unknown PPC board" >&2
> +		exit 1
> +	fi
> +
> +	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
> +	;;
> +esac
> +
> +if [ ! -e "$QEMU_BIN" ]; then
> +	echo "\
> +Could not find a usable QEMU binary. Please install one from \
> +your distro or from source code using:
> +
> +  $ git clone git://git.qemu.org/qemu.git
> +  $ cd qemu
> +  $ ./configure
> +  $ make -j
> +  $ sudo make install
> +" >&2
> +	exit 1
> +fi
> +
> +# The binaries without kvm in their name can be too old to support KVM, so
> +# check for that before the user gets confused
> +if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
> +     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
> +	echo "Your QEMU binary is too old, please update to at least 0.15." >&2
> +	exit 1
> +fi
> +QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
> +
> +# We need to check some .config variables to make sure we actually work
> +# on the respective kernel.
> +if [ ! -e .config ]; then
> +	echo "\
> +Please run this script on a fully compiled and configured
> +Linux kernel build directory" >&2
> +	exit 1
> +fi
> +
> +if [ ! -e "$KERNEL_BIN" ]; then
> +	echo "Could not find kernel binary: $KERNEL_BIN" >&2
> +	exit 1
> +fi
> +
> +QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
> +
> +if [ "$USE_SDL" ]; then
> +	# SDL is the default, so nothing to do
> +	:
> +elif [ "$USE_VNC" ]; then
> +	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
> +else
> +	# When emulating a serial console, tell the kernel to use it as well
> +	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
> +	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
> +	MON_STDIO=1
> +	require_config "$SERIAL_KCONFIG"
> +fi
> +
> +if [ "$ROOTFS" ]; then
> +	# Using rootfs with 9p
> +	require_config "NET_9P_VIRTIO"

+ require_config "9P_FS"

> +	KERNEL_APPEND="$KERNEL_APPEND \
> +root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
> +
> +#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
> +
> +
> +	QEMU_OPTIONS="$QEMU_OPTIONS \
> +-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
> +-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
> +fi
> +
> +[ "$SMP" ] || SMP=1
> +
> +# User append args come last
> +KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
> +
> +############### Execution #################
> +
> +QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
> +
> +echo "
> +	################# Linux QEMU launcher #################
> +
> +This script executes your currently built Linux kernel using QEMU. If KVM is
> +available, it will also use KVM for fast virtualization of your guest.
> +
> +The intent is to make it very easy to run your kernel. If you need to do more
> +advanced things, such as passing through real devices, please use QEMU command
> +line options and add them to the $BASENAME command line using --.
> +
> +This tool is for simplicity, not world dominating functionality coverage.
> +(just a hobby, won't be big and professional like libvirt)
> +
> +"
> +
> +if [ "$MON_STDIO" ]; then
> +	echo "\
> +### Your guest is bound to the current foreground shell. To quit the guest, ###
> +### please use Ctrl-A x                                                     ###
> +"
> +fi
> +
> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\""
> +echo
> +
> +GDB_PID=
> +if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
> +	# Run a gdb console in parallel to the kernel
> +
> +	# XXX find out if port is in use
> +	PORT=$$
> +	xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
> +	GDB_PID=$!
> +	QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
> +fi
> +
> +$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
> +wait $GDB_PID &>/dev/null
> +

Nice that it forks off a gdb session. I will contribute my gdb helper
script soon (module symbol loading, dmesg, per-cpu variable lookup etc.)
so that it can be loaded automatically.

Jan


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Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 06.11.2011, at 14:54, Jan Kiszka wrote:

> On 2011-08-24 23:38, Alexander Graf wrote:
>> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
>> would be doing and what he expects from it. Basically he wants a
>> small and simple tool he and other developers can run to try out and
>> see if the kernel they just built actually works.
>> 
>> Fortunately, QEMU can do that today already! The only piece that was
>> missing was the "simple" piece of the equation, so here is a script
>> that wraps around QEMU and executes a kernel you just built.
>> 
>> If you do have KVM around and are not cross-compiling, it will use
>> KVM. But if you don't, you can still fall back to emulation mode and
>> at least check if your kernel still does what you expect. I only
>> implemented support for s390x and ppc there, but it's easily extensible
>> to more platforms, as QEMU can emulate (and virtualize) pretty much
>> any platform out there.
>> 
>> If you don't have qemu installed, please do so before using this script. Your
>> distro should provide a package for it (might even call it "kvm"). If not,
>> just compile it from source - it's not hard!
>> 
>> To quickly get going, just execute the following as user:
>> 
>>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>> 
>> This will drop you into a shell on your rootfs.
>> 
>> Happy hacking!
>> 
>> Signed-off-by: Alexander Graf <agraf@suse.de>
>> 
>> ---
>> 
>> v1 -> v2:
>> 
>>  - fix naming of QEMU
>>  - use grep -q for has_config
>>  - support multiple -a args
>>  - spawn gdb on execution
>>  - pass through qemu options
>>  - dont use qemu-system-x86_64 on i386
>>  - add funny sentence to startup text
>>  - more helpful error messages
>> ---
>> scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 files changed, 334 insertions(+), 0 deletions(-)
>> create mode 100755 scripts/run-qemu.sh
>> 
>> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
>> new file mode 100755
>> index 0000000..5d4e185
>> --- /dev/null
>> +++ b/scripts/run-qemu.sh
>> @@ -0,0 +1,334 @@
>> +#!/bin/bash
>> +#
>> +# QEMU Launcher
>> +#
>> +# This script enables simple use of the KVM and QEMU tool stack for
>> +# easy kernel testing. It allows to pass either a host directory to
>> +# the guest or a disk image. Example usage:
>> +#
>> +# Run the host root fs inside a VM:
>> +#
>> +# $ ./scripts/run-qemu.sh -r /
>> +#
>> +# Run the same with SDL:
>> +#
>> +# $ ./scripts/run-qemu.sh -r / --sdl
>> +# 
>> +# Or with a PPC build:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +# 
>> +# PPC with a mac99 model by passing options to QEMU:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +#
>> +
>> +USE_SDL=
>> +USE_VNC=
>> +USE_GDB=1
>> +KERNEL_BIN=arch/x86/boot/bzImage
>> +MON_STDIO=
>> +KERNEL_APPEND2=
>> +SERIAL=ttyS0
>> +SERIAL_KCONFIG=SERIAL_8250
>> +BASENAME=$(basename "$0")
>> +
>> +function usage() {
>> +	echo "
>> +$BASENAME allows you to execute a virtual machine with the Linux kernel
>> +that you just built. To only execute a simple VM, you can just run it
>> +on your root fs with \"-r / -a init=/bin/bash\"
>> +
>> +	-a, --append parameters
>> +		Append the given parameters to the kernel command line.
>> +
>> +	-d, --disk image
>> +		Add the image file as disk into the VM.
>> +
>> +	-D, --no-gdb
>> +		Don't run an xterm with gdb attached to the guest.
>> +
>> +	-r, --root directory
>> +		Use the specified directory as root directory inside the guest.
>> +
>> +	-s, --sdl
>> +		Enable SDL graphical output.
>> +
>> +	-S, --smp cpus
>> +		Set number of virtual CPUs.
>> +
>> +	-v, --vnc
>> +		Enable VNC graphical output.
>> +
>> +Examples:
>> +
>> +	Run the host root fs inside a VM:
>> +	$ ./scripts/run-qemu.sh -r /
>> +
>> +	Run the same with SDL:
>> +	$ ./scripts/run-qemu.sh -r / --sdl
>> +	
>> +	Or with a PPC build:
>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +	
>> +	PPC with a mac99 model by passing options to QEMU:
>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +"
>> +}
>> +
>> +function require_config() {
>> +	if [ "$(grep CONFIG_$1=y .config)" ]; then
>> +		return
>> +	fi
>> +
>> +	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
>> +	exit 1
>> +}
>> +
>> +function has_config() {
>> +	grep -q "CONFIG_$1=y" .config
>> +}
>> +
>> +function drive_if() {
>> +	if has_config VIRTIO_BLK; then
>> +		echo virtio
>> +	elif has_config ATA_PIIX; then
>> +		echo ide
> 
> + require_config "BLK_DEV_SD"
> 
> Maybe there should also be a warning if no standard FS (ext[34], btrfs,
> xfs etc.) is build into the kernel.
> 
> Another thing, but that's just a recommendation for initrd-free mode:
> DEVTMPFS_MOUNT
> 
>> +	else
>> +		echo "\
>> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
>> +enabled for block device assignment" >&2
>> +		exit 1
>> +	fi
>> +}
>> +
>> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
>> +	-n "$(basename \"$0\")" -- "$@"`
>> +
>> +if [ $? != 0 ]; then
>> +	echo "Terminating..." >&2
>> +	exit 1
>> +fi
>> +
>> +eval set -- "$GETOPT"
>> +
>> +while true; do
>> +	case "$1" in
>> +	-a|--append)
>> +		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
> 
> That should be
> 
> KERNEL_APPEND2="$KERNEL_APPEND2 $2"
> 
>> +		shift
>> +		;;
>> +	-d|--disk)
>> +		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
>> +			file=$2,if=$(drive_if),cache=unsafe"
> 
> 		if [ $? != 0 ]; then
> 			exit $?
> 		fi

Not sure I understand this one. There's no program executing here...


Alex

Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 06.11.2011, at 14:54, Jan Kiszka wrote:

> On 2011-08-24 23:38, Alexander Graf wrote:
>> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
>> would be doing and what he expects from it. Basically he wants a
>> small and simple tool he and other developers can run to try out and
>> see if the kernel they just built actually works.
>> 
>> Fortunately, QEMU can do that today already! The only piece that was
>> missing was the "simple" piece of the equation, so here is a script
>> that wraps around QEMU and executes a kernel you just built.
>> 
>> If you do have KVM around and are not cross-compiling, it will use
>> KVM. But if you don't, you can still fall back to emulation mode and
>> at least check if your kernel still does what you expect. I only
>> implemented support for s390x and ppc there, but it's easily extensible
>> to more platforms, as QEMU can emulate (and virtualize) pretty much
>> any platform out there.
>> 
>> If you don't have qemu installed, please do so before using this script. Your
>> distro should provide a package for it (might even call it "kvm"). If not,
>> just compile it from source - it's not hard!
>> 
>> To quickly get going, just execute the following as user:
>> 
>>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>> 
>> This will drop you into a shell on your rootfs.
>> 
>> Happy hacking!
>> 
>> Signed-off-by: Alexander Graf <agraf@suse.de>
>> 
>> ---
>> 
>> v1 -> v2:
>> 
>>  - fix naming of QEMU
>>  - use grep -q for has_config
>>  - support multiple -a args
>>  - spawn gdb on execution
>>  - pass through qemu options
>>  - dont use qemu-system-x86_64 on i386
>>  - add funny sentence to startup text
>>  - more helpful error messages
>> ---
>> scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 files changed, 334 insertions(+), 0 deletions(-)
>> create mode 100755 scripts/run-qemu.sh
>> 
>> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
>> new file mode 100755
>> index 0000000..5d4e185
>> --- /dev/null
>> +++ b/scripts/run-qemu.sh
>> @@ -0,0 +1,334 @@
>> +#!/bin/bash
>> +#
>> +# QEMU Launcher
>> +#
>> +# This script enables simple use of the KVM and QEMU tool stack for
>> +# easy kernel testing. It allows to pass either a host directory to
>> +# the guest or a disk image. Example usage:
>> +#
>> +# Run the host root fs inside a VM:
>> +#
>> +# $ ./scripts/run-qemu.sh -r /
>> +#
>> +# Run the same with SDL:
>> +#
>> +# $ ./scripts/run-qemu.sh -r / --sdl
>> +# 
>> +# Or with a PPC build:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +# 
>> +# PPC with a mac99 model by passing options to QEMU:
>> +#
>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +#
>> +
>> +USE_SDL=
>> +USE_VNC=
>> +USE_GDB=1
>> +KERNEL_BIN=arch/x86/boot/bzImage
>> +MON_STDIO=
>> +KERNEL_APPEND2=
>> +SERIAL=ttyS0
>> +SERIAL_KCONFIG=SERIAL_8250
>> +BASENAME=$(basename "$0")
>> +
>> +function usage() {
>> +	echo "
>> +$BASENAME allows you to execute a virtual machine with the Linux kernel
>> +that you just built. To only execute a simple VM, you can just run it
>> +on your root fs with \"-r / -a init=/bin/bash\"
>> +
>> +	-a, --append parameters
>> +		Append the given parameters to the kernel command line.
>> +
>> +	-d, --disk image
>> +		Add the image file as disk into the VM.
>> +
>> +	-D, --no-gdb
>> +		Don't run an xterm with gdb attached to the guest.
>> +
>> +	-r, --root directory
>> +		Use the specified directory as root directory inside the guest.
>> +
>> +	-s, --sdl
>> +		Enable SDL graphical output.
>> +
>> +	-S, --smp cpus
>> +		Set number of virtual CPUs.
>> +
>> +	-v, --vnc
>> +		Enable VNC graphical output.
>> +
>> +Examples:
>> +
>> +	Run the host root fs inside a VM:
>> +	$ ./scripts/run-qemu.sh -r /
>> +
>> +	Run the same with SDL:
>> +	$ ./scripts/run-qemu.sh -r / --sdl
>> +	
>> +	Or with a PPC build:
>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r /
>> +	
>> +	PPC with a mac99 model by passing options to QEMU:
>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>> +"
>> +}
>> +
>> +function require_config() {
>> +	if [ "$(grep CONFIG_$1=y .config)" ]; then
>> +		return
>> +	fi
>> +
>> +	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
>> +	exit 1
>> +}
>> +
>> +function has_config() {
>> +	grep -q "CONFIG_$1=y" .config
>> +}
>> +
>> +function drive_if() {
>> +	if has_config VIRTIO_BLK; then
>> +		echo virtio
>> +	elif has_config ATA_PIIX; then
>> +		echo ide
> 
> + require_config "BLK_DEV_SD"
> 
> Maybe there should also be a warning if no standard FS (ext[34], btrfs,
> xfs etc.) is build into the kernel.
> 
> Another thing, but that's just a recommendation for initrd-free mode:
> DEVTMPFS_MOUNT
> 
>> +	else
>> +		echo "\
>> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
>> +enabled for block device assignment" >&2
>> +		exit 1
>> +	fi
>> +}
>> +
>> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
>> +	-n "$(basename \"$0\")" -- "$@"`
>> +
>> +if [ $? != 0 ]; then
>> +	echo "Terminating..." >&2
>> +	exit 1
>> +fi
>> +
>> +eval set -- "$GETOPT"
>> +
>> +while true; do
>> +	case "$1" in
>> +	-a|--append)
>> +		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
> 
> That should be
> 
> KERNEL_APPEND2="$KERNEL_APPEND2 $2"
> 
>> +		shift
>> +		;;
>> +	-d|--disk)
>> +		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
>> +			file=$2,if=$(drive_if),cache=unsafe"
> 
> 		if [ $? != 0 ]; then
> 			exit $?
> 		fi

Not sure I understand this one. There's no program executing here...


Alex

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

[-- Attachment #1: Type: text/plain, Size: 6073 bytes --]

On 2012-05-11 10:42, Alexander Graf wrote:
> 
> On 06.11.2011, at 14:54, Jan Kiszka wrote:
> 
>> On 2011-08-24 23:38, Alexander Graf wrote:
>>> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
>>> would be doing and what he expects from it. Basically he wants a
>>> small and simple tool he and other developers can run to try out and
>>> see if the kernel they just built actually works.
>>>
>>> Fortunately, QEMU can do that today already! The only piece that was
>>> missing was the "simple" piece of the equation, so here is a script
>>> that wraps around QEMU and executes a kernel you just built.
>>>
>>> If you do have KVM around and are not cross-compiling, it will use
>>> KVM. But if you don't, you can still fall back to emulation mode and
>>> at least check if your kernel still does what you expect. I only
>>> implemented support for s390x and ppc there, but it's easily extensible
>>> to more platforms, as QEMU can emulate (and virtualize) pretty much
>>> any platform out there.
>>>
>>> If you don't have qemu installed, please do so before using this script. Your
>>> distro should provide a package for it (might even call it "kvm"). If not,
>>> just compile it from source - it's not hard!
>>>
>>> To quickly get going, just execute the following as user:
>>>
>>>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>>>
>>> This will drop you into a shell on your rootfs.
>>>
>>> Happy hacking!
>>>
>>> Signed-off-by: Alexander Graf <agraf@suse.de>
>>>
>>> ---
>>>
>>> v1 -> v2:
>>>
>>>  - fix naming of QEMU
>>>  - use grep -q for has_config
>>>  - support multiple -a args
>>>  - spawn gdb on execution
>>>  - pass through qemu options
>>>  - dont use qemu-system-x86_64 on i386
>>>  - add funny sentence to startup text
>>>  - more helpful error messages
>>> ---
>>> scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>> 1 files changed, 334 insertions(+), 0 deletions(-)
>>> create mode 100755 scripts/run-qemu.sh
>>>
>>> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
>>> new file mode 100755
>>> index 0000000..5d4e185
>>> --- /dev/null
>>> +++ b/scripts/run-qemu.sh
>>> @@ -0,0 +1,334 @@
>>> +#!/bin/bash
>>> +#
>>> +# QEMU Launcher
>>> +#
>>> +# This script enables simple use of the KVM and QEMU tool stack for
>>> +# easy kernel testing. It allows to pass either a host directory to
>>> +# the guest or a disk image. Example usage:
>>> +#
>>> +# Run the host root fs inside a VM:
>>> +#
>>> +# $ ./scripts/run-qemu.sh -r /
>>> +#
>>> +# Run the same with SDL:
>>> +#
>>> +# $ ./scripts/run-qemu.sh -r / --sdl
>>> +# 
>>> +# Or with a PPC build:
>>> +#
>>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
>>> +# 
>>> +# PPC with a mac99 model by passing options to QEMU:
>>> +#
>>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>>> +#
>>> +
>>> +USE_SDL=
>>> +USE_VNC=
>>> +USE_GDB=1
>>> +KERNEL_BIN=arch/x86/boot/bzImage
>>> +MON_STDIO=
>>> +KERNEL_APPEND2=
>>> +SERIAL=ttyS0
>>> +SERIAL_KCONFIG=SERIAL_8250
>>> +BASENAME=$(basename "$0")
>>> +
>>> +function usage() {
>>> +	echo "
>>> +$BASENAME allows you to execute a virtual machine with the Linux kernel
>>> +that you just built. To only execute a simple VM, you can just run it
>>> +on your root fs with \"-r / -a init=/bin/bash\"
>>> +
>>> +	-a, --append parameters
>>> +		Append the given parameters to the kernel command line.
>>> +
>>> +	-d, --disk image
>>> +		Add the image file as disk into the VM.
>>> +
>>> +	-D, --no-gdb
>>> +		Don't run an xterm with gdb attached to the guest.
>>> +
>>> +	-r, --root directory
>>> +		Use the specified directory as root directory inside the guest.
>>> +
>>> +	-s, --sdl
>>> +		Enable SDL graphical output.
>>> +
>>> +	-S, --smp cpus
>>> +		Set number of virtual CPUs.
>>> +
>>> +	-v, --vnc
>>> +		Enable VNC graphical output.
>>> +
>>> +Examples:
>>> +
>>> +	Run the host root fs inside a VM:
>>> +	$ ./scripts/run-qemu.sh -r /
>>> +
>>> +	Run the same with SDL:
>>> +	$ ./scripts/run-qemu.sh -r / --sdl
>>> +	
>>> +	Or with a PPC build:
>>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r /
>>> +	
>>> +	PPC with a mac99 model by passing options to QEMU:
>>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>>> +"
>>> +}
>>> +
>>> +function require_config() {
>>> +	if [ "$(grep CONFIG_$1=y .config)" ]; then
>>> +		return
>>> +	fi
>>> +
>>> +	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
>>> +	exit 1
>>> +}
>>> +
>>> +function has_config() {
>>> +	grep -q "CONFIG_$1=y" .config
>>> +}
>>> +
>>> +function drive_if() {
>>> +	if has_config VIRTIO_BLK; then
>>> +		echo virtio
>>> +	elif has_config ATA_PIIX; then
>>> +		echo ide
>>
>> + require_config "BLK_DEV_SD"
>>
>> Maybe there should also be a warning if no standard FS (ext[34], btrfs,
>> xfs etc.) is build into the kernel.
>>
>> Another thing, but that's just a recommendation for initrd-free mode:
>> DEVTMPFS_MOUNT
>>
>>> +	else
>>> +		echo "\
>>> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
>>> +enabled for block device assignment" >&2
>>> +		exit 1
>>> +	fi
>>> +}
>>> +
>>> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
>>> +	-n "$(basename \"$0\")" -- "$@"`
>>> +
>>> +if [ $? != 0 ]; then
>>> +	echo "Terminating..." >&2
>>> +	exit 1
>>> +fi
>>> +
>>> +eval set -- "$GETOPT"
>>> +
>>> +while true; do
>>> +	case "$1" in
>>> +	-a|--append)
>>> +		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
>>
>> That should be
>>
>> KERNEL_APPEND2="$KERNEL_APPEND2 $2"
>>
>>> +		shift
>>> +		;;
>>> +	-d|--disk)
>>> +		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
>>> +			file=$2,if=$(drive_if),cache=unsafe"
>>
>> 		if [ $? != 0 ]; then
>> 			exit $?
>> 		fi
> 
> Not sure I understand this one. There's no program executing here...

Not sure either. Does drive_if exit the complete script when it fails?
Maybe it was related to this, give it a try again.

Jan


[-- Attachment #2: OpenPGP digital signature --]
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Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

[-- Attachment #1: Type: text/plain, Size: 6073 bytes --]

On 2012-05-11 10:42, Alexander Graf wrote:
> 
> On 06.11.2011, at 14:54, Jan Kiszka wrote:
> 
>> On 2011-08-24 23:38, Alexander Graf wrote:
>>> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
>>> would be doing and what he expects from it. Basically he wants a
>>> small and simple tool he and other developers can run to try out and
>>> see if the kernel they just built actually works.
>>>
>>> Fortunately, QEMU can do that today already! The only piece that was
>>> missing was the "simple" piece of the equation, so here is a script
>>> that wraps around QEMU and executes a kernel you just built.
>>>
>>> If you do have KVM around and are not cross-compiling, it will use
>>> KVM. But if you don't, you can still fall back to emulation mode and
>>> at least check if your kernel still does what you expect. I only
>>> implemented support for s390x and ppc there, but it's easily extensible
>>> to more platforms, as QEMU can emulate (and virtualize) pretty much
>>> any platform out there.
>>>
>>> If you don't have qemu installed, please do so before using this script. Your
>>> distro should provide a package for it (might even call it "kvm"). If not,
>>> just compile it from source - it's not hard!
>>>
>>> To quickly get going, just execute the following as user:
>>>
>>>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>>>
>>> This will drop you into a shell on your rootfs.
>>>
>>> Happy hacking!
>>>
>>> Signed-off-by: Alexander Graf <agraf@suse.de>
>>>
>>> ---
>>>
>>> v1 -> v2:
>>>
>>>  - fix naming of QEMU
>>>  - use grep -q for has_config
>>>  - support multiple -a args
>>>  - spawn gdb on execution
>>>  - pass through qemu options
>>>  - dont use qemu-system-x86_64 on i386
>>>  - add funny sentence to startup text
>>>  - more helpful error messages
>>> ---
>>> scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>> 1 files changed, 334 insertions(+), 0 deletions(-)
>>> create mode 100755 scripts/run-qemu.sh
>>>
>>> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
>>> new file mode 100755
>>> index 0000000..5d4e185
>>> --- /dev/null
>>> +++ b/scripts/run-qemu.sh
>>> @@ -0,0 +1,334 @@
>>> +#!/bin/bash
>>> +#
>>> +# QEMU Launcher
>>> +#
>>> +# This script enables simple use of the KVM and QEMU tool stack for
>>> +# easy kernel testing. It allows to pass either a host directory to
>>> +# the guest or a disk image. Example usage:
>>> +#
>>> +# Run the host root fs inside a VM:
>>> +#
>>> +# $ ./scripts/run-qemu.sh -r /
>>> +#
>>> +# Run the same with SDL:
>>> +#
>>> +# $ ./scripts/run-qemu.sh -r / --sdl
>>> +# 
>>> +# Or with a PPC build:
>>> +#
>>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
>>> +# 
>>> +# PPC with a mac99 model by passing options to QEMU:
>>> +#
>>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>>> +#
>>> +
>>> +USE_SDL=
>>> +USE_VNC=
>>> +USE_GDB=1
>>> +KERNEL_BIN=arch/x86/boot/bzImage
>>> +MON_STDIO=
>>> +KERNEL_APPEND2=
>>> +SERIAL=ttyS0
>>> +SERIAL_KCONFIG=SERIAL_8250
>>> +BASENAME=$(basename "$0")
>>> +
>>> +function usage() {
>>> +	echo "
>>> +$BASENAME allows you to execute a virtual machine with the Linux kernel
>>> +that you just built. To only execute a simple VM, you can just run it
>>> +on your root fs with \"-r / -a init=/bin/bash\"
>>> +
>>> +	-a, --append parameters
>>> +		Append the given parameters to the kernel command line.
>>> +
>>> +	-d, --disk image
>>> +		Add the image file as disk into the VM.
>>> +
>>> +	-D, --no-gdb
>>> +		Don't run an xterm with gdb attached to the guest.
>>> +
>>> +	-r, --root directory
>>> +		Use the specified directory as root directory inside the guest.
>>> +
>>> +	-s, --sdl
>>> +		Enable SDL graphical output.
>>> +
>>> +	-S, --smp cpus
>>> +		Set number of virtual CPUs.
>>> +
>>> +	-v, --vnc
>>> +		Enable VNC graphical output.
>>> +
>>> +Examples:
>>> +
>>> +	Run the host root fs inside a VM:
>>> +	$ ./scripts/run-qemu.sh -r /
>>> +
>>> +	Run the same with SDL:
>>> +	$ ./scripts/run-qemu.sh -r / --sdl
>>> +	
>>> +	Or with a PPC build:
>>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r /
>>> +	
>>> +	PPC with a mac99 model by passing options to QEMU:
>>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>>> +"
>>> +}
>>> +
>>> +function require_config() {
>>> +	if [ "$(grep CONFIG_$1=y .config)" ]; then
>>> +		return
>>> +	fi
>>> +
>>> +	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
>>> +	exit 1
>>> +}
>>> +
>>> +function has_config() {
>>> +	grep -q "CONFIG_$1=y" .config
>>> +}
>>> +
>>> +function drive_if() {
>>> +	if has_config VIRTIO_BLK; then
>>> +		echo virtio
>>> +	elif has_config ATA_PIIX; then
>>> +		echo ide
>>
>> + require_config "BLK_DEV_SD"
>>
>> Maybe there should also be a warning if no standard FS (ext[34], btrfs,
>> xfs etc.) is build into the kernel.
>>
>> Another thing, but that's just a recommendation for initrd-free mode:
>> DEVTMPFS_MOUNT
>>
>>> +	else
>>> +		echo "\
>>> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
>>> +enabled for block device assignment" >&2
>>> +		exit 1
>>> +	fi
>>> +}
>>> +
>>> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
>>> +	-n "$(basename \"$0\")" -- "$@"`
>>> +
>>> +if [ $? != 0 ]; then
>>> +	echo "Terminating..." >&2
>>> +	exit 1
>>> +fi
>>> +
>>> +eval set -- "$GETOPT"
>>> +
>>> +while true; do
>>> +	case "$1" in
>>> +	-a|--append)
>>> +		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
>>
>> That should be
>>
>> KERNEL_APPEND2="$KERNEL_APPEND2 $2"
>>
>>> +		shift
>>> +		;;
>>> +	-d|--disk)
>>> +		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
>>> +			file=$2,if=$(drive_if),cache=unsafe"
>>
>> 		if [ $? != 0 ]; then
>> 			exit $?
>> 		fi
> 
> Not sure I understand this one. There's no program executing here...

Not sure either. Does drive_if exit the complete script when it fails?
Maybe it was related to this, give it a try again.

Jan


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Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

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On 2012-05-11 10:42, Alexander Graf wrote:
> 
> On 06.11.2011, at 14:54, Jan Kiszka wrote:
> 
>> On 2011-08-24 23:38, Alexander Graf wrote:
>>> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
>>> would be doing and what he expects from it. Basically he wants a
>>> small and simple tool he and other developers can run to try out and
>>> see if the kernel they just built actually works.
>>>
>>> Fortunately, QEMU can do that today already! The only piece that was
>>> missing was the "simple" piece of the equation, so here is a script
>>> that wraps around QEMU and executes a kernel you just built.
>>>
>>> If you do have KVM around and are not cross-compiling, it will use
>>> KVM. But if you don't, you can still fall back to emulation mode and
>>> at least check if your kernel still does what you expect. I only
>>> implemented support for s390x and ppc there, but it's easily extensible
>>> to more platforms, as QEMU can emulate (and virtualize) pretty much
>>> any platform out there.
>>>
>>> If you don't have qemu installed, please do so before using this script. Your
>>> distro should provide a package for it (might even call it "kvm"). If not,
>>> just compile it from source - it's not hard!
>>>
>>> To quickly get going, just execute the following as user:
>>>
>>>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>>>
>>> This will drop you into a shell on your rootfs.
>>>
>>> Happy hacking!
>>>
>>> Signed-off-by: Alexander Graf <agraf@suse.de>
>>>
>>> ---
>>>
>>> v1 -> v2:
>>>
>>>  - fix naming of QEMU
>>>  - use grep -q for has_config
>>>  - support multiple -a args
>>>  - spawn gdb on execution
>>>  - pass through qemu options
>>>  - dont use qemu-system-x86_64 on i386
>>>  - add funny sentence to startup text
>>>  - more helpful error messages
>>> ---
>>> scripts/run-qemu.sh |  334 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>> 1 files changed, 334 insertions(+), 0 deletions(-)
>>> create mode 100755 scripts/run-qemu.sh
>>>
>>> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
>>> new file mode 100755
>>> index 0000000..5d4e185
>>> --- /dev/null
>>> +++ b/scripts/run-qemu.sh
>>> @@ -0,0 +1,334 @@
>>> +#!/bin/bash
>>> +#
>>> +# QEMU Launcher
>>> +#
>>> +# This script enables simple use of the KVM and QEMU tool stack for
>>> +# easy kernel testing. It allows to pass either a host directory to
>>> +# the guest or a disk image. Example usage:
>>> +#
>>> +# Run the host root fs inside a VM:
>>> +#
>>> +# $ ./scripts/run-qemu.sh -r /
>>> +#
>>> +# Run the same with SDL:
>>> +#
>>> +# $ ./scripts/run-qemu.sh -r / --sdl
>>> +# 
>>> +# Or with a PPC build:
>>> +#
>>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r /
>>> +# 
>>> +# PPC with a mac99 model by passing options to QEMU:
>>> +#
>>> +# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>>> +#
>>> +
>>> +USE_SDL=
>>> +USE_VNC=
>>> +USE_GDB=1
>>> +KERNEL_BIN=arch/x86/boot/bzImage
>>> +MON_STDIO=
>>> +KERNEL_APPEND2=
>>> +SERIAL=ttyS0
>>> +SERIAL_KCONFIG=SERIAL_8250
>>> +BASENAME=$(basename "$0")
>>> +
>>> +function usage() {
>>> +	echo "
>>> +$BASENAME allows you to execute a virtual machine with the Linux kernel
>>> +that you just built. To only execute a simple VM, you can just run it
>>> +on your root fs with \"-r / -a init=/bin/bash\"
>>> +
>>> +	-a, --append parameters
>>> +		Append the given parameters to the kernel command line.
>>> +
>>> +	-d, --disk image
>>> +		Add the image file as disk into the VM.
>>> +
>>> +	-D, --no-gdb
>>> +		Don't run an xterm with gdb attached to the guest.
>>> +
>>> +	-r, --root directory
>>> +		Use the specified directory as root directory inside the guest.
>>> +
>>> +	-s, --sdl
>>> +		Enable SDL graphical output.
>>> +
>>> +	-S, --smp cpus
>>> +		Set number of virtual CPUs.
>>> +
>>> +	-v, --vnc
>>> +		Enable VNC graphical output.
>>> +
>>> +Examples:
>>> +
>>> +	Run the host root fs inside a VM:
>>> +	$ ./scripts/run-qemu.sh -r /
>>> +
>>> +	Run the same with SDL:
>>> +	$ ./scripts/run-qemu.sh -r / --sdl
>>> +	
>>> +	Or with a PPC build:
>>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r /
>>> +	
>>> +	PPC with a mac99 model by passing options to QEMU:
>>> +	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
>>> +"
>>> +}
>>> +
>>> +function require_config() {
>>> +	if [ "$(grep CONFIG_$1=y .config)" ]; then
>>> +		return
>>> +	fi
>>> +
>>> +	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
>>> +	exit 1
>>> +}
>>> +
>>> +function has_config() {
>>> +	grep -q "CONFIG_$1=y" .config
>>> +}
>>> +
>>> +function drive_if() {
>>> +	if has_config VIRTIO_BLK; then
>>> +		echo virtio
>>> +	elif has_config ATA_PIIX; then
>>> +		echo ide
>>
>> + require_config "BLK_DEV_SD"
>>
>> Maybe there should also be a warning if no standard FS (ext[34], btrfs,
>> xfs etc.) is build into the kernel.
>>
>> Another thing, but that's just a recommendation for initrd-free mode:
>> DEVTMPFS_MOUNT
>>
>>> +	else
>>> +		echo "\
>>> +Your kernel must have either VIRTIO_BLK or ATA_PIIX
>>> +enabled for block device assignment" >&2
>>> +		exit 1
>>> +	fi
>>> +}
>>> +
>>> +GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
>>> +	-n "$(basename \"$0\")" -- "$@"`
>>> +
>>> +if [ $? != 0 ]; then
>>> +	echo "Terminating..." >&2
>>> +	exit 1
>>> +fi
>>> +
>>> +eval set -- "$GETOPT"
>>> +
>>> +while true; do
>>> +	case "$1" in
>>> +	-a|--append)
>>> +		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
>>
>> That should be
>>
>> KERNEL_APPEND2="$KERNEL_APPEND2 $2"
>>
>>> +		shift
>>> +		;;
>>> +	-d|--disk)
>>> +		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
>>> +			file=$2,if=$(drive_if),cache=unsafe"
>>
>> 		if [ $? != 0 ]; then
>> 			exit $?
>> 		fi
> 
> Not sure I understand this one. There's no program executing here...

Not sure either. Does drive_if exit the complete script when it fails?
Maybe it was related to this, give it a try again.

Jan


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[PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
would be doing and what he expects from it. Basically he wants a
small and simple tool he and other developers can run to try out and
see if the kernel they just built actually works.

Fortunately, QEMU can do that today already! The only piece that was
missing was the "simple" piece of the equation, so here is a script
that wraps around QEMU and executes a kernel you just built.

If you do have KVM around and are not cross-compiling, it will use
KVM. But if you don't, you can still fall back to emulation mode and
at least check if your kernel still does what you expect. I only
implemented support for s390x and ppc there, but it's easily extensible
to more platforms, as QEMU can emulate (and virtualize) pretty much
any platform out there.

If you don't have qemu installed, please do so before using this script. Your
distro should provide a package for it (might even call it "kvm"). If not,
just compile it from source - it's not hard!

To quickly get going, just execute the following as user:

    $ ./tools/testing/run-qemu/run-qemu.sh -r / -a init=/bin/bash

This will drop you into a shell on your rootfs.

Or you can also use a ready made image:

    $ IMG=http://people.debian.org/~aurel32/qemu/amd64
    $ IMG="$IMG/debian_squeeze_amd64_standard.qcow2"
    $ ./tools/testing/run-qemu/run-qemu.sh -d $IMG \
        -a "root=/dev/vda1 init=/bin/bash"

Keep in mind that http is read-only, so no writing to the image :).

Either way, you provide the kernel. QEMU provides the test environment!
Easy, eh?

Happy hacking!

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - fix naming of QEMU
  - use grep -q for has_config
  - support multiple -a args
  - spawn gdb on execution
  - pass through qemu options
  - dont use qemu-system-x86_64 on i386
  - add funny sentence to startup text
  - more helpful error messages

v2 -> v3:

  - move to tools/testing
  - fix running: message

v3 -> v4:

  - update to new path everywhere
  - check for sd module in ide case
  - fix -a
  - simplify KERNEL_BIN setting code
  - check for qemu-system-i386
  - require CONFIG_9P_FS in 9p case
  - add QEMU version check
  - check for success of drive_if
  - mention QEMU_BIN environment variable in help
---
 tools/testing/run-qemu/run-qemu.sh |  361 ++++++++++++++++++++++++++++++++++++
 1 files changed, 361 insertions(+), 0 deletions(-)
 create mode 100755 tools/testing/run-qemu/run-qemu.sh

diff --git a/tools/testing/run-qemu/run-qemu.sh b/tools/testing/run-qemu/run-qemu.sh
new file mode 100755
index 0000000..f4fa6e7
--- /dev/null
+++ b/tools/testing/run-qemu/run-qemu.sh
@@ -0,0 +1,361 @@
+#!/bin/bash
+#
+# QEMU Launcher
+#
+# This script enables simple use of the KVM and QEMU tool stack for
+# easy kernel testing. It allows to pass either a host directory to
+# the guest or a disk image. Example usage:
+#
+# Run the host root fs inside a VM:
+#
+# $ ./tools/testing/run-qemu/run-qemu.sh -r /
+#
+# Run the same with SDL:
+#
+# $ ./tools/testing/run-qemu/run-qemu.sh -r / --sdl
+#
+# Or with a PPC build:
+#
+# $ ARCH=ppc ./tools/testing/run-qemu/run-qemu.sh -r /
+#
+# PPC with a mac99 model by passing options to QEMU:
+#
+# $ ARCH=ppc ./tools/testing/run-qemu/run-qemu.sh -r / -- -M mac99
+#
+
+USE_SDL=
+USE_VNC=
+USE_GDB=1
+KERNEL_BIN=arch/x86/boot/bzImage
+MON_STDIO=
+KERNEL_APPEND2=
+SERIAL=ttyS0
+SERIAL_KCONFIG=SERIAL_8250
+BASENAME=$(basename "$0")
+
+function usage() {
+	echo "
+$BASENAME allows you to execute a virtual machine with the Linux kernel
+that you just built. To only execute a simple VM, you can just run it
+on your root fs with \"-r / -a init=/bin/bash\"
+
+	-a, --append parameters
+		Append the given parameters to the kernel command line.
+
+	-d, --disk image
+		Add the image file as disk into the VM.
+
+	-D, --no-gdb
+		Don't run an xterm with gdb attached to the guest.
+
+	-r, --root directory
+		Use the specified directory as root directory inside the guest.
+
+	-s, --sdl
+		Enable SDL graphical output.
+
+	-S, --smp cpus
+		Set number of virtual CPUs.
+
+	-v, --vnc
+		Enable VNC graphical output.
+
+Examples:
+
+	Run the host root fs inside a VM:
+	$ ./tools/testing/run-qemu/run-qemu.sh -r /
+
+	Run the same with SDL:
+	$ ./tools/testing/run-qemu/run-qemu.sh -r / --sdl
+
+	Or with a PPC build:
+	$ ARCH=ppc ./tools/testing/run-qemu/run-qemu.sh -r /
+
+	PPC with a mac99 model by passing options to QEMU:
+	$ ARCH=ppc ./tools/testing/run-qemu/run-qemu.sh -r / -- -M mac99
+"
+}
+
+function require_config() {
+	if [ "$(grep CONFIG_$1=y .config)" ]; then
+		return
+	fi
+
+	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
+	exit 1
+}
+
+function has_config() {
+	grep -q "CONFIG_$1=y" .config
+}
+
+function drive_if() {
+	if has_config VIRTIO_BLK; then
+		echo virtio
+	elif has_config ATA_PIIX; then
+		require_config "BLK_DEV_SD"
+		echo ide
+	else
+		echo "\
+Your kernel must have either VIRTIO_BLK or ATA_PIIX
+enabled for block device assignment" >&2
+		exit 1
+	fi
+}
+
+function verify_qemu() {
+	QEMU="$(which $1 2>/dev/null)"
+
+	# binary exists?
+	[ -x "$QEMU" ] || exit 1
+
+	# we need a version that knows -machine
+	if ! "$QEMU" --help | grep -q -- '-machine'; then
+		exit 1
+	fi
+
+	echo "$QEMU"
+	exit 0
+}
+
+GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
+	-n "$(basename \"$0\")" -- "$@"`
+
+if [ $? != 0 ]; then
+	echo "Terminating..." >&2
+	exit 1
+fi
+
+eval set -- "$GETOPT"
+
+while true; do
+	case "$1" in
+	-a|--append)
+		KERNEL_APPEND2="$KERNEL_APPEND2 $2"
+		shift
+		;;
+	-d|--disk)
+		set -e
+		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
+			file=$2,if=$(drive_if),cache=unsafe"
+		set +e
+		USE_DISK=1
+		shift
+		;;
+	-D|--no-gdb)
+		USE_GDB=
+		;;
+	-h|--help)
+		usage
+		exit 0
+		;;
+	-r|--root)
+		ROOTFS="$2"
+		shift
+		;;
+	-s|--sdl)
+		USE_SDL=1
+		;;
+	-S|--smp)
+		SMP="$2"
+		shift
+		;;
+	-v|--vnc)
+		USE_VNC=1
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		echo "Could not parse option: $1" >&2
+		exit 1
+		;;
+	esac
+	shift
+done
+
+if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
+	echo "\
+Error: Please specify at least -r or -d with a target \
+FS to run off of" >&2
+	exit 1
+fi
+
+# Try to find the KVM accelerated QEMU binary
+
+[ "$ARCH" ] || ARCH=$(uname -m)
+case $ARCH in
+x86_64)
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(verify_qemu qemu-kvm)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(verify_qemu kvm)
+
+	# QEMU's own build system calls it qemu-system-x86_64
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(verify_qemu qemu-system-x86_64)
+	;;
+i*86)
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(verify_qemu qemu-kvm)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(verify_qemu kvm)
+
+	# new i386 version of QEMU
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(verify_qemu qemu-system-i386)
+
+	# i386 version of QEMU
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(verify_qemu qemu)
+	;;
+s390*)
+	KERNEL_BIN=arch/s390/boot/image
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(verify_qemu qemu-system-s390x)
+	;;
+ppc*)
+	KERNEL_BIN=vmlinux
+
+	IS_64BIT=
+	has_config PPC64 && IS_64BIT=64
+	if has_config PPC_85xx; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
+	elif has_config PPC_PSERIES; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
+		SERIAL=hvc0
+		SERIAL_KCONFIG=HVC_CONSOLE
+	elif has_config PPC_PMAC; then
+		has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
+		SERIAL_KCONFIG=SERIAL_PMACZILOG
+	else
+		echo "Unknown PPC board" >&2
+		exit 1
+	fi
+
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
+	;;
+esac
+
+if [ ! -e "$QEMU_BIN" ]; then
+	echo "\
+Could not find a usable QEMU binary. Please install one from \
+your distro or from source code using:
+
+  $ git clone git://git.qemu.org/qemu.git
+  $ cd qemu
+  $ ./configure
+  $ make -j
+  $ sudo make install
+
+or point this script to a working version of qemu using
+
+  $ export QEMU_BIN=/path/to/qemu-kvm
+" >&2
+	exit 1
+fi
+
+# The binaries without kvm in their name can be too old to support KVM, so
+# check for that before the user gets confused
+if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
+     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
+	echo "Your QEMU binary is too old, please update to at least 0.15." >&2
+	exit 1
+fi
+QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
+
+# We need to check some .config variables to make sure we actually work
+# on the respective kernel.
+if [ ! -e .config ]; then
+	echo "\
+Please run this script on a fully compiled and configured
+Linux kernel build directory" >&2
+	exit 1
+fi
+
+if [ ! -e "$KERNEL_BIN" ]; then
+	echo "Could not find kernel binary: $KERNEL_BIN" >&2
+	exit 1
+fi
+
+QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
+
+if [ "$USE_SDL" ]; then
+	# SDL is the default, so nothing to do
+	:
+elif [ "$USE_VNC" ]; then
+	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
+else
+	# When emulating a serial console, tell the kernel to use it as well
+	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
+	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
+	MON_STDIO=1
+	require_config "$SERIAL_KCONFIG"
+fi
+
+if [ "$ROOTFS" ]; then
+	# Using rootfs with 9p
+	require_config "NET_9P_VIRTIO"
+	require_config "9P_FS"
+	KERNEL_APPEND="$KERNEL_APPEND \
+root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
+
+#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
+
+
+	QEMU_OPTIONS="$QEMU_OPTIONS \
+-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
+-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
+fi
+
+[ "$SMP" ] || SMP=1
+
+# User append args come last
+KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
+
+############### Execution #################
+
+QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
+
+echo "
+	################# Linux QEMU launcher #################
+
+This script executes your currently built Linux kernel using QEMU. If KVM is
+available, it will also use KVM for fast virtualization of your guest.
+
+The intent is to make it very easy to run your kernel. If you need to do more
+advanced things, such as passing through real devices, please use QEMU command
+line options and add them to the $BASENAME command line using --.
+
+This tool is for simplicity, not world dominating functionality coverage.
+(just a hobby, won't be big and professional like libvirt)
+
+"
+
+if [ "$MON_STDIO" ]; then
+	echo "\
+### Your guest is bound to the current foreground shell. To quit the guest, ###
+### please use Ctrl-A x                                                     ###
+"
+fi
+
+echo -n "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\" "
+for i in "$@"; do
+	echo -n "\"$i\" "
+done
+echo
+echo
+
+GDB_PID=
+if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
+	# Run a gdb console in parallel to the kernel
+
+	# XXX find out if port is in use
+	PORT=$(( $$ + 1024 ))
+	xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
+	GDB_PID=$!
+	QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
+fi
+
+$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
+wait $GDB_PID &>/dev/null
+
-- 
1.6.0.2

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Vince Weaver]

On Tue, 8 Nov 2011, Arnaldo Carvalho de Melo wrote:

> Em Tue, Nov 08, 2011 at 01:07:55PM +0100, Ingo Molnar escreveu:
> > * Vince Weaver <vince@deater.net> wrote:
> > > as mentioned before I have my own perf_event test suite with 20+ tests.
> > >   http://web.eecs.utk.edu/~vweaver1/projects/perf-events/validation.html
>  
> > That should probably be moved into perf test. Arnaldo, any 
> > objections?
> 
> I'd gladly take patches, I even have in my TODO list for me to volunteer
> time to do that at some point.
> 
> If somebody else than me or Vince wants to do that... Assuming there is
> no licensing problem and Vince doesn't objects for that to be done.

I have no objections, though I don't really have time right now to do the 
work myself.

The test code is licensed dual GPLv2/BSD.  I should stick that in the 
package somewhere if I haven't already.

My testcases mostly are testing things necessary for proper PAPI 
functionality and are by no means complete.  There are huge
areas of perf_event functionality that are not well tested, especially
the overflow code.

Vince

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/08/2011 07:34 PM, Alexander Graf wrote:
>>
>>> It could work with a btrfs snapshot, but not everyone uses that.
>> Or LVM snapshot.  Either way, just reusing the root fs without care
>> is a dumb idea, and I really don't want any tool or script that
>> encurages such braindead behaviour in the kernel tree.
>
>
> Heh, yeah, the intent was obviously to have a separate rootfs tree
> somewhere in a directory. But that's not available at first when
> running this, so I figured for a simple "get me rolling" FAQ directing
> the guest's rootfs to / at least gets you somewhere (especially when
> run as user with init=/bin/bash).
>

Right, init=/bin/bash is not too insane for rootfs passthrough.

/proc will be completely broken though, need to mount the guest's.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 11/08/2011 03:59 PM, Christoph Hellwig wrote:
> On Tue, Nov 08, 2011 at 04:57:04PM +0200, Avi Kivity wrote:
>>> Running qemu -snapshot on the actual root block device is the only
>>> safe way to reuse the host installation, although it gets a bit
>>> complicated if people have multiple devices mounted into the namespace.
>> How is -snapshot any different?  If the host writes a block after the
>> guest has been launched, but before that block was cowed, then the guest
>> will see the new block.
> Right, thinko - qemu's snapshots are fairly useless due to sitting
> ontop of the file to be modified.
>
>> It could work with a btrfs snapshot, but not everyone uses that.
> Or LVM snapshot.  Either way, just reusing the root fs without care
> is a dumb idea, and I really don't want any tool or script that
> encurages such braindead behaviour in the kernel tree.

Heh, yeah, the intent was obviously to have a separate rootfs tree 
somewhere in a directory. But that's not available at first when running 
this, so I figured for a simple "get me rolling" FAQ directing the 
guest's rootfs to / at least gets you somewhere (especially when run as 
user with init=/bin/bash).

Alex

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Christoph Hellwig]

On Tue, Nov 08, 2011 at 05:26:03PM +0200, Pekka Enberg wrote:
> On Tue, Nov 8, 2011 at 4:52 PM, Christoph Hellwig <hch@infradead.org> wrote:
> > Nevermind that running virtfs as a rootfs is a really dumb idea. ?You
> > do now want to run a VM that has a rootfs that gets changed all the
> > time behind your back.
> 
> It's rootfs binaries that are shared, not configuration. It's
> unfortunate but works OK for the single user use case it's meant for.
> It's obviously not a proper solution for the generic case. We were
> hoping that we could use something like overlayfs to hide the issue
> under the rug. Do you think that's also a really dumb thing to do?

It doesn't hide your issues.  Any kind of unioning will have massive
consistency issues (as in will corrupt your fs if you do stupid things)
if the underlying layer is allowed to be written to.  Thus all the
fuzz about making sure the underlying fs can never be mounted writeable
in the union mount patches.

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Tue, Nov 8, 2011 at 4:52 PM, Christoph Hellwig <hch@infradead.org> wrote:
> Nevermind that running virtfs as a rootfs is a really dumb idea.  You
> do now want to run a VM that has a rootfs that gets changed all the
> time behind your back.

It's rootfs binaries that are shared, not configuration. It's
unfortunate but works OK for the single user use case it's meant for.
It's obviously not a proper solution for the generic case. We were
hoping that we could use something like overlayfs to hide the issue
under the rug. Do you think that's also a really dumb thing to do?

Using block device snapshotting would be interesting and we should
definitely look into that.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Tue, Nov 8, 2011 at 4:52 PM, Christoph Hellwig <hch@infradead.org> wrote:
> Nevermind that running virtfs as a rootfs is a really dumb idea.  You
> do now want to run a VM that has a rootfs that gets changed all the
> time behind your back.

It's rootfs binaries that are shared, not configuration. It's
unfortunate but works OK for the single user use case it's meant for.
It's obviously not a proper solution for the generic case. We were
hoping that we could use something like overlayfs to hide the issue
under the rug. Do you think that's also a really dumb thing to do?

Using block device snapshotting would be interesting and we should
definitely look into that.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

[-- Attachment #1: Type: text/plain, Size: 1440 bytes --]

On 2011-11-08 15:52, Christoph Hellwig wrote:
> On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote:
>> On 11/06/2011 03:35 AM, Alexander Graf wrote:
>>> To quickly get going, just execute the following as user:
>>>
>>>     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>>>
>>> This will drop you into a shell on your rootfs.
>>>
>>
>> Doesn't work on Fedora 15.  F15's qemu-kvm doesn't have -machine or
>> -virtfs.  Even qemu.git on F15 won't build virtfs since xattr.h
>> detection is broken (patch posted).
> 
> Nevermind that running virtfs as a rootfs is a really dumb idea.  You
> do now want to run a VM that has a rootfs that gets changed all the
> time behind your back.
> 
> Running qemu -snapshot on the actual root block device is the only
> safe way to reuse the host installation, although it gets a bit
> complicated if people have multiple devices mounted into the namespace.

I thought about this while hacking a slide on this topic: It's clumsy
(compared to -snapshot - my favorite one as well), but you could use
some snapshot on the host fs. Or a union fs (if we had  an official one)
with the write layer directed to some tmpfs area.

But what we likely rather want (as it would work without privileges) is
built-in write redirection for virtfs. Not an expert on this, but I
guess that will have to solve the same problems an in-kernel union fs
solution faces, no?

Jan


[-- Attachment #2: OpenPGP digital signature --]
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Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Christoph Hellwig]

On Tue, Nov 08, 2011 at 04:57:04PM +0200, Avi Kivity wrote:
> > Running qemu -snapshot on the actual root block device is the only
> > safe way to reuse the host installation, although it gets a bit
> > complicated if people have multiple devices mounted into the namespace.
> 
> How is -snapshot any different?  If the host writes a block after the
> guest has been launched, but before that block was cowed, then the guest
> will see the new block.

Right, thinko - qemu's snapshots are fairly useless due to sitting
ontop of the file to be modified.

> It could work with a btrfs snapshot, but not everyone uses that.

Or LVM snapshot.  Either way, just reusing the root fs without care
is a dumb idea, and I really don't want any tool or script that
encurages such braindead behaviour in the kernel tree.

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

On 11/08/2011 04:52 PM, Christoph Hellwig wrote:
> On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote:
> > On 11/06/2011 03:35 AM, Alexander Graf wrote:
> > > To quickly get going, just execute the following as user:
> > >
> > >     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
> > >
> > > This will drop you into a shell on your rootfs.
> > >
> > 
> > Doesn't work on Fedora 15.  F15's qemu-kvm doesn't have -machine or
> > -virtfs.  Even qemu.git on F15 won't build virtfs since xattr.h
> > detection is broken (patch posted).
>
> Nevermind that running virtfs as a rootfs is a really dumb idea.  You
> do now want to run a VM that has a rootfs that gets changed all the
> time behind your back.

True.

> Running qemu -snapshot on the actual root block device is the only
> safe way to reuse the host installation, although it gets a bit
> complicated if people have multiple devices mounted into the namespace.

How is -snapshot any different?  If the host writes a block after the
guest has been launched, but before that block was cowed, then the guest
will see the new block.

It could work with a btrfs snapshot, but not everyone uses that.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/08/2011 04:52 PM, Christoph Hellwig wrote:
> On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote:
> > On 11/06/2011 03:35 AM, Alexander Graf wrote:
> > > To quickly get going, just execute the following as user:
> > >
> > >     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
> > >
> > > This will drop you into a shell on your rootfs.
> > >
> > 
> > Doesn't work on Fedora 15.  F15's qemu-kvm doesn't have -machine or
> > -virtfs.  Even qemu.git on F15 won't build virtfs since xattr.h
> > detection is broken (patch posted).
>
> Nevermind that running virtfs as a rootfs is a really dumb idea.  You
> do now want to run a VM that has a rootfs that gets changed all the
> time behind your back.

True.

> Running qemu -snapshot on the actual root block device is the only
> safe way to reuse the host installation, although it gets a bit
> complicated if people have multiple devices mounted into the namespace.

How is -snapshot any different?  If the host writes a block after the
guest has been launched, but before that block was cowed, then the guest
will see the new block.

It could work with a btrfs snapshot, but not everyone uses that.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Sasha Levin]

On Tue, Nov 8, 2011 at 4:52 PM, Christoph Hellwig <hch@infradead.org> wrote:
> On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote:
>> On 11/06/2011 03:35 AM, Alexander Graf wrote:
>> > To quickly get going, just execute the following as user:
>> >
>> >     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>> >
>> > This will drop you into a shell on your rootfs.
>> >
>>
>> Doesn't work on Fedora 15.  F15's qemu-kvm doesn't have -machine or
>> -virtfs.  Even qemu.git on F15 won't build virtfs since xattr.h
>> detection is broken (patch posted).
>
> Nevermind that running virtfs as a rootfs is a really dumb idea.  You
> do now want to run a VM that has a rootfs that gets changed all the
> time behind your back.
>
> Running qemu -snapshot on the actual root block device is the only
> safe way to reuse the host installation, although it gets a bit
> complicated if people have multiple devices mounted into the namespace.

Using block devices also requires root.

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Sasha Levin]

On Tue, Nov 8, 2011 at 4:52 PM, Christoph Hellwig <hch@infradead.org> wrote:
> On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote:
>> On 11/06/2011 03:35 AM, Alexander Graf wrote:
>> > To quickly get going, just execute the following as user:
>> >
>> >     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>> >
>> > This will drop you into a shell on your rootfs.
>> >
>>
>> Doesn't work on Fedora 15.  F15's qemu-kvm doesn't have -machine or
>> -virtfs.  Even qemu.git on F15 won't build virtfs since xattr.h
>> detection is broken (patch posted).
>
> Nevermind that running virtfs as a rootfs is a really dumb idea.  You
> do now want to run a VM that has a rootfs that gets changed all the
> time behind your back.
>
> Running qemu -snapshot on the actual root block device is the only
> safe way to reuse the host installation, although it gets a bit
> complicated if people have multiple devices mounted into the namespace.

Using block devices also requires root.

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Christoph Hellwig]

On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote:
> On 11/06/2011 03:35 AM, Alexander Graf wrote:
> > To quickly get going, just execute the following as user:
> >
> >     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
> >
> > This will drop you into a shell on your rootfs.
> >
> 
> Doesn't work on Fedora 15.  F15's qemu-kvm doesn't have -machine or
> -virtfs.  Even qemu.git on F15 won't build virtfs since xattr.h
> detection is broken (patch posted).

Nevermind that running virtfs as a rootfs is a really dumb idea.  You
do now want to run a VM that has a rootfs that gets changed all the
time behind your back.

Running qemu -snapshot on the actual root block device is the only
safe way to reuse the host installation, although it gets a bit
complicated if people have multiple devices mounted into the namespace.

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 03:35 AM, Alexander Graf wrote:
> To quickly get going, just execute the following as user:
>
>     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>
> This will drop you into a shell on your rootfs.
>

Doesn't work on Fedora 15.  F15's qemu-kvm doesn't have -machine or
-virtfs.  Even qemu.git on F15 won't build virtfs since xattr.h
detection is broken (patch posted).

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Tue, Nov 8, 2011 at 3:29 PM, Karel Zak <kzak@redhat.com> wrote:
>> I don't know if it makes sense to merge the tools you've mentioned above.
>> My gut feeling is that it's probably not reasonable - there's already a
>> community working on it with their own development process and coding
>> style. I don't think there's a simple answer to this but I don't agree with
>> your rather extreme position that all userspace tools should be kept out
>> of the kernel tree.
>
> Ted's position is not extreme. He follows the simple and exactly defined
> border between userspace and kernel. The native userspace feature is
> variability and substitutability.

It's an extreme position because he's arguing that we should only have
kernel code in the tree or we need open up to all userspace code.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Tue, Nov 8, 2011 at 3:29 PM, Karel Zak <kzak@redhat.com> wrote:
>> I don't know if it makes sense to merge the tools you've mentioned above.
>> My gut feeling is that it's probably not reasonable - there's already a
>> community working on it with their own development process and coding
>> style. I don't think there's a simple answer to this but I don't agree with
>> your rather extreme position that all userspace tools should be kept out
>> of the kernel tree.
>
> Ted's position is not extreme. He follows the simple and exactly defined
> border between userspace and kernel. The native userspace feature is
> variability and substitutability.

It's an extreme position because he's arguing that we should only have
kernel code in the tree or we need open up to all userspace code.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Karel Zak]

On Mon, Nov 07, 2011 at 03:12:28PM +0200, Pekka Enberg wrote:
> On Mon, Nov 7, 2011 at 2:47 PM, Ted Ts'o <tytso@mit.edu> wrote:
> > I don't think perf should be used as a precendent that now argues that
> > any new kernel utility should be moved into the kernel sources.  Does
> > it make sense to move all of mount, fsck, login, etc., into the kernel
> > sources?  There are far more kernel tools outside of the kernel
> > sources than inside the kernel sources.

[...]

> I don't know if it makes sense to merge the tools you've mentioned above.
> My gut feeling is that it's probably not reasonable - there's already a
> community working on it with their own development process and coding
> style. I don't think there's a simple answer to this but I don't agree with
> your rather extreme position that all userspace tools should be kept out
> of the kernel tree.

Ted's position is not extreme. He follows the simple and exactly defined
border between userspace and kernel. The native userspace feature is
variability and substitutability.

The util-linux package is really nice example:

  - you don't have to use it, you can use busybox

  - we have currently three implementation of login(1), many getty 
    implementations, etc.

  - it's normal that people use the latest util-linux releases with very 
    old kernels (in year 2008 I had report from person with kernel 2.4:-)

  - userspace is very often about portability -- it's crazy, but some people
    use some utils from util-linux on Hurd, Solaris and BSD (including very
    Linux specific things like mkswap and hwclock)


Anyway, I agree that small one-man projects are ineffective for
important system tools -- it's usually better to merge things into
large projects with reliable infrastructure and alive community (here
I agree with Lennart's idea to have 3-5 projects for whole low-level
userspace). 

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Arnaldo Carvalho de Melo]

Em Tue, Nov 08, 2011 at 01:07:55PM +0100, Ingo Molnar escreveu:
> * Vince Weaver <vince@deater.net> wrote:
> > as mentioned before I have my own perf_event test suite with 20+ tests.
> >   http://web.eecs.utk.edu/~vweaver1/projects/perf-events/validation.html
 
> That should probably be moved into perf test. Arnaldo, any 
> objections?

I'd gladly take patches, I even have in my TODO list for me to volunteer
time to do that at some point.

If somebody else than me or Vince wants to do that... Assuming there is
no licensing problem and Vince doesn't objects for that to be done.

I know that at least the QE team at Red Hat uses it and I hope other QE
teams do it.

- Arnaldo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Ingo Molnar]

* Vince Weaver <vince@deater.net> wrote:

> On Mon, 7 Nov 2011, Ingo Molnar wrote:

> > I think we needed to do only one revert along the way in the past 
> > two years, to fix an unintended ABI breakage in PowerTop. 
> > Considering the total complexity of the perf ABI our 
> > compatibility track record is *very* good.
> 
> There have been more breakages, as you know.  It's just they 
> weren't caught in time so they were declared to be grandfathered in 
> rather than fixed.

I remember one such instance were you reported a 'regression' that 
spanned several -stable kernel releases - and unless the fix is easy 
and obvious that's the regular upstream treatment.

As Linus said it too on the recent Kernel Summit an ABI is only an 
ABI if it's actually *used*.

But there's more, you've repeatedly rejected our offer to extend 
'perf test' to cover the functionality that your library relies on. 
If you refuse to timely test newer upstream kernels while you rely on 
obscure details that nobody else uses and if you refuse to make your 
testcases more prominent it becomes *your* problem.

There's not much we can do if you refuse to test and refuse to push 
your testcases upstream ...

> > ... and you have argued against perf from the very first day on, 
> > when you were one of the perfmon developers - and IMO in 
> > hindsight you've been repeatedly wrong about most of your design 
> > arguments.
> 
> I can't find an exact e-mail, but I seem to recall my arguments 
> were that Pentium 4 support would be hard (it was), [...]

To the contrary, a single person implemented most of it, out of 
curiosity.

> [...] that in-kernel generalized events were a bad idea (I still 
> think that, try talking to the ARM guys sometime about that) [...]

To the contrary, generalized events work very well and they are one 
of the reasons why the perf tooling is so usable.

> [...] and that making access to raw events hard (by not using a 
> naming library) was silly. [...]

To the contrary, by 'making it easy' you mean 'translate hexa codes 
to vendor specific gibberish' which is hardly any better to actual 
users of the tool and gives the false appearance of being a solution.

All in one you advocated all the oprofile design mistakes and you 
have been proven thoroughly wrong by reality.

> > The PAPI project has the (fundamental) problem that you are still 
> > doing it in the old-style sw design fashion, with many months 
> > long delays in testing, and then you are blaming the problems you 
> > inevitably meet with that model on *us*.
> 
> The fundamental problem with the PAPI project is that we only have 
> 3 full-time developers, and we have to make sure PAPI runs on about 
> 10 different platforms, of which perf_events/Linux is only one.
> 
> Time I waste tracking down perf_event ABI regressions and DoS bugs 
> takes away from actual useful userspace PAPI development.

If people are not interested in even testing the basic test-suite of 
PAPI on a recent kernel then i'm afraid there must be something very 
wrong with the PAPI project structure.

Somehow that testing is not missing from the perf tool, despite it 
being a much younger and smaller project. Did you ever stop to think 
why that is so?

> > There was one PAPI incident i remember where it took you several 
> > *months* to report a regression in a regular PAPI test-case (no 
> > actual app affected as far as i know). No other tester ever ran 
> > the PAPI testcases so nobody else reported it.
> 
> We have a huge userbase.  They run on some pretty amazing machines 
> and do some tests that strain perf libraries to the limit. They 
> also tend to use distro kernels, assuming they even have moved to 
> 2.6.31+ kernels yet.  When these power users report problems, they 
> aren't going to be against the -tip tree.

Nobody expects you to test the -tip tree if you don't want to (it 
would certainly be useful to you if you are interested in PMU 
development), but there's a 2.5 months stabilization window after the 
upstream merge.

> > Nobody but you tests PAPI so you need to become *part* of the 
> > upstream development process, which releases a new upstream 
> > kernel every 3 months.
> 
> PAPI is a free software project, with the devel tree available from 
> CVS. It takes maybe 15 minutes to run the full PAPI regression 
> suite. I encourage you or any perf developer to try it and report 
> any issues.

I will fix what gets reported and neither i nor other regular kernel 
testers actually use it.

You really need to do more testing to fill that gap, expecting others 
to volunteer time into a project they don't actually use is extremely 
backwards...

> I can only be so comprehensive.  I didn't find the current 
> NMI-watchdog regression right away because my git tree builds 
> didn't have it enabled.  It wasn't until there started being 3.0 
> distro kernels that people started reporting the problem to us.
>
> > Also, as i mentioned it several times before, you are free to add 
> > an arbitrary number of ABI test-cases to 'perf test' and we can 
> > promise that we run that. Right now it consists of a few tests:
> 
> as mentioned before I have my own perf_event test suite with 20+ tests.
>   http://web.eecs.utk.edu/~vweaver1/projects/perf-events/validation.html

That should probably be moved into perf test. Arnaldo, any 
objections?

> I do run it often.  It tends to be reactionary though, as I can 
> only add a test for a bug once I know about it.
> 
> I also have more up-to date perf documentation than the kernel does:
>   http://web.eecs.utk.edu/~vweaver1/projects/perf-events/programming.html
> 
> and a cpu compatability matrix:
>   http://web.eecs.utk.edu/~vweaver1/projects/perf-events/support.html
> 
> I didn't really want to turn this into yet another perf flamewar.  

So why then did you launch several malicious, unprovoked, 
passive-aggressive ad hominem attacks against perf developers, like:

  "Never overtly.  They're too clever for that."

and:

  "Unlike the perf developers, we *do* have to maintain backwards
   compatability."

? They were untrue, uncalled for, unfair and outright mean-spirited.

Thanks,

	Ingo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Theodore Tso]

On Nov 7, 2011, at 5:19 PM, Anthony Liguori wrote:

> 
> The kernel ecosystem does not have to be limited to linux.git.  There could be a process to be a "kernel.org project" for projects that fit a certain set of criteria.  These projects could all share the Linux kernel release cadence and have a kernel maintainer as a sponsor or something like that.
> 
> That is something that could potentially benefit things like e2fs-tools and all of the other tools that are tied closely to the kernel.

We have that already.   Packages such as e2fsprogs, xfsprogs, xfstests, sparse, git, etc., have git trees under git.kernel.org.  And I agree that's the perfect place for kvm-tool and perf.   :-)

-- Ted

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Anthony Liguori]

On 11/07/2011 03:36 PM, Pekka Enberg wrote:
> Hi Ted,
>
> On Mon, Nov 7, 2011 at 10:32 PM, Ted Ts'o<tytso@mit.edu>  wrote:
>> Personally, I consider code that runs in userspace as a pretty bright
>> line, as being "not kernel code", and while perhaps things like
>> initramfs and the crazy ideas people have had in the past of moving
>> stuff out of kernel/init.c into userspace might have qualified as
>> stuff really close to the kernel, something like kvm-tool that runs
>> way after boot, doesn't even come close.  Wine is another example of
>> another package that has lots of close kernel ties, but was also not
>> bundled into the kernel.
>
> It's not as clear line as you make it out to be.
>
> KVM tool also has mini-BIOS code that runs in guest space. It has a
> code that runs in userspace but is effectively a simple bootloader. So
> it definitely doesn't fit the simple definition of "running way after
> boot" (we're _booting_ the kernel too).
>
> Linsched fits your definition but is clearly worth integrating to the
> kernel tree. While you are suggesting that maybe we should move Perf
> out of the tree now that it's mature, I'm pretty sure you'd agree that
> it probably would not have happened if the userspace parts were
> developed out of tree.
>
> There's also spectacular failures in the kernel history where the
> userspace split was enforced. For example, userspace suspend didn't
> turn out the way people envisioned it at the time. We don't know how
> it would have worked out if the userspace components would have been
> in the tree but it certainly would have solved many if the early ABI
> issues.
>
> I guess I'm trying to argue here that there's a middle ground. I'm
> willing to bet projects like klibc and unified initramfs will
> eventually make it to the kernel tree because they simply make so much
> sense. I'm also willing to be that the costs of moving Perf out of the
> tree are simply too high to make it worthwhile.
>
> Does that mean KVM tool should get a free pass in merging? Absolutely
> not. But I do think your position is too extreme and ignores the
> benefits of developing userspace tools in the kernel ecosystem which
> was summed up by Anthony rather well in this thread:
>
> https://lkml.org/lkml/2011/11/7/169

The kernel ecosystem does not have to be limited to linux.git.  There could be a 
process to be a "kernel.org project" for projects that fit a certain set of 
criteria.  These projects could all share the Linux kernel release cadence and 
have a kernel maintainer as a sponsor or something like that.

That is something that could potentially benefit things like e2fs-tools and all 
of the other tools that are tied closely to the kernel.

In fact, having a single place where users could find all of the various kernel 
related tools and helpers would probably be extremely useful.  There's no reason 
this needs to be linux.git though, this could just be a web page on kernel.org.

Regards,

Anthony Liguori

>
>                                  Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Ted Ts'o]

On Mon, Nov 07, 2011 at 09:53:28PM +0200, Pekka Enberg wrote:
> 
> I'm sure perf developers break the ABI sometimes - that happens
> elsewhere in the kernel as well. However, Ted claimed that perf
> developers use tools/perf as an excuse to break the ABI _on purpose_
> which is something I have hard time believing.

I remember an assertion, probably a year or two ago, probably at the
previous year's kernel summit, that one of the reasons for having the
perf code inline in the kernel was so that synchronized changes could
be made to both the kernel and userspace tool together.  So it's not a
matter of breaking the ABI _on_ _purpose_, it's an assertion that
there is no ABI at all.  Since the perf tool and the kernel tool have
to be built together, so long as a user does that, no harm, no foul.
Recall that Linus has said that he doesn't care about whether or not
something is an ABI; he only care if users code don't perceive
breakage.  If they didn't perceive breakage, then it doesn't matter if
an interface is changed.

So the real question is whether or not this was an excuse to break the
ABI, but whether or not the perf developers acknowledge there is an
ABI at all, and whether it's OK for other developers to depend on the
syscall interface or not.  Actually, though, it shouldn't matter,
because intentions don't matter.

Recall the powertop/ftrace case.  If you expose an interface, and
people start using that interface, then you can't break them, period.
So as far as Vince is concerned, if you have a userspace library which
depends on the perf interface, then you should try out the kernel
after each merge window, and if your library breaks, you should
complain to Ingo and Linus directly, and request that the commit which
broke your tool to be reverted --- because that's the rule; no
breakage is allowed.

As far as kvm-tool being in the kernel, I still don't see particularly
valid arguments for why it should be in the kernel.  It can't be the
perf argument of "we can make simultaneous changes in the userspace
and kernel code", because if those changes break qemu-kvm, then a
complaint to Linus will cause the problem code to be reverted.

As far as the code using the same coding conventions and naming
conventions as the kernel, that to me isn't a particular strong
argument either.  E2fsprogs uses the Signed-off-by lines, and the same
coding conventions of the kernel, and it even has a slightly modified
version of two kernel source file in e2fsprogs (e2fsck/recovery.c and
e2fsck/revoke.c), plus a header file with data structures that have to
be kept in sync with the kernel header file.  But that doesn't make it
"part of the kernel", and it's not a justification for it to be
bundled with the kernel.

Personally, I consider code that runs in userspace as a pretty bright
line, as being "not kernel code", and while perhaps things like
initramfs and the crazy ideas people have had in the past of moving
stuff out of kernel/init.c into userspace might have qualified as
stuff really close to the kernel, something like kvm-tool that runs
way after boot, doesn't even come close.  Wine is another example of
another package that has lots of close kernel ties, but was also not
bundled into the kernel.

The precedent has all mainly been on the "keep the kernel separate"
side of things, and the arguments for bundling it with the kernel are
much weaker, especially since the interface is well-developed, and
there are external users of the interface which means you can't make
changes to the interface willy-nilly.

Indeed, when the perf interface was changing all the time, maybe there
was some convenience to have it be bundled with the kernel, so there
was no need to negotiate interface version numbers, et. al.  But given
how it has to link in so many user space libraries, I personally think
it's fair to ask the question whether now that it has matured, whether
it's time to move it out of the kernel source tree.

Regards,

							- Ted

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, 7 Nov 2011, Frank Ch. Eigler wrote:
>> The ABI design allows for that kind of flexible extensibility, and
>> it's one of its major advantages.
>>
>> What we *cannot* protect against is you relying on obscure details of
>> the ABI [...]
>
> Is there some documentation that clearly spells out which parts of the
> perf syscall userspace ABI are "obscure" and thus presumably
> changeable?

That's actually something the KVM and virtio folks have done a great job 
with IMHO. Both ABIs are documented pretty extensively and the specs are 
kept up to date.

I guess for perf ABI, "perf test" is the closest thing to a specification 
so if your application is using something that's not covered by it, you 
might be in trouble.

 			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Frank Ch. Eigler]

Ingo Molnar <mingo@elte.hu> writes:

> [...]
>> It's problem enough that there's no way to know what version of the 
>> perf_event abi you are running against and we have to guess based 
>> on kernel version.  This gets "fun" because all of the vendors have 
>> backported seemingly random chunks of perf_event code to their 
>> older kernels.
>
> The ABI design allows for that kind of flexible extensibility, and 
> it's one of its major advantages.
>
> What we *cannot* protect against is you relying on obscure details of 
> the ABI [...]

Is there some documentation that clearly spells out which parts of the
perf syscall userspace ABI are "obscure" and thus presumably
changeable?

> [...]  The usual ABI rules also apply: we'll revert everything that
> breaks the ABI - but for that you need to report it *in time* [...]

If the ABI is so great in its flexible extensibility, how come it
can't be flexibly extended without having to passing the burden of
compatibility testing & reversion-yawping to someone else?


- FChE

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Vince Weaver]

On Mon, 7 Nov 2011, Pekka Enberg wrote:

> I've never heard ABI incompatibility used as an argument for perf. Ingo?

Never overtly.  They're too clever for that.

In any case, as a primary developer of a library (PAPI) that uses the 
perf_events ABI I have to say that having perf in the kernel has been a 
*major* pain for us.

Unlike the perf developers, we *do* have to maintain backwards 
compatability.  And we have a lot of nasty code in PAPI to handle this.
Entirely because the perf_events ABI is not stable.  It's mostly stable, 
but there are enough regressions to be a pain.

It's problem enough that there's no way to know what version of the 
perf_event abi you are running against and we have to guess based on 
kernel version.  This gets "fun" because all of the vendors have 
backported seemingly random chunks of perf_event code to their older 
kernels.

And it often does seem as the perf developers don't care when something 
breaks in perf_events if it doesn't affect perf users.

For example, the new NMI watchdog severely breaks perf_event event 
allocation if you are using FORMAT_GROUP.  perf doesn't use this though, 
so none of the kernel developers seem to care.  And unless I can quickly 
come up with a patch as an outsider, a few kernel versions will go by and 
the kernel devs will declare "well it was broken so long, now we don't 
have to fix it".  Fun.

Vince

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[青云]

[-- Attachment #1: Type: text/plain, Size: 1474 bytes --]

I know kgdb can test kernel,but I haven't succeed .
  
 
------------------ Original ------------------
From: "Pekka Enberg"; 
Date: 2011年11月7日(星期一) 下午4:57
To: "Paolo Bonzini"; 
Cc: "Alexander Graf"; "kvm@vger.kernel.org list"; "qemu-devel Developers"; "linux-kernel@vger.kernel.org List"; "Blue Swirl"; "Avi Kivity"; "Américo Wan"; "Ingo Molnar"; "Linus Torvalds"; 
Subject: Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

 
On 11/07/2011 09:45 AM, Pekka Enberg wrote:
>>> Specifications matter much more than working code.  Quirks are a fact
>>> of life but should always come second.
>>
>> To quote Linus:
>>
>>   And I have seen _lots_ of total crap work that was based on specs. It's
>> _the_ single worst way to write software, because it by definition means
>>   that the software was written to match theory, not reality.

On Mon, Nov 7, 2011 at 10:52 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> All generalizations are false.

What is that supposed to mean? You claimed we're "doing it wrong" and
I explained you why we are doing it the way we are.

Really, the way we do things in the KVM tool is not a bug, it's a feature.

                        Pekka
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Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 2:47 PM, Ted Ts'o <tytso@mit.edu> wrote:
> I don't think perf should be used as a precendent that now argues that
> any new kernel utility should be moved into the kernel sources.  Does
> it make sense to move all of mount, fsck, login, etc., into the kernel
> sources?  There are far more kernel tools outside of the kernel
> sources than inside the kernel sources.

You seem to think that the KVM tool was developed in isolation and we
simply copied the code to tools/kvm for the pull request. That's simply
not true. We've done a lot of work to make the code feel like kernel code
from locking primitive APIs to serial console emulation register names.
We really consider KVM tool to be a new Linux subsystem. It's the long
lost cousin or bastard child of KVM, depending on who you ask.

I don't know if it makes sense to merge the tools you've mentioned above.
My gut feeling is that it's probably not reasonable - there's already a
community working on it with their own development process and coding
style. I don't think there's a simple answer to this but I don't agree with
your rather extreme position that all userspace tools should be kept out
of the kernel tree.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 2:47 PM, Ted Ts'o <tytso@mit.edu> wrote:
> I don't think perf should be used as a precendent that now argues that
> any new kernel utility should be moved into the kernel sources.  Does
> it make sense to move all of mount, fsck, login, etc., into the kernel
> sources?  There are far more kernel tools outside of the kernel
> sources than inside the kernel sources.

You seem to think that the KVM tool was developed in isolation and we
simply copied the code to tools/kvm for the pull request. That's simply
not true. We've done a lot of work to make the code feel like kernel code
from locking primitive APIs to serial console emulation register names.
We really consider KVM tool to be a new Linux subsystem. It's the long
lost cousin or bastard child of KVM, depending on who you ask.

I don't know if it makes sense to merge the tools you've mentioned above.
My gut feeling is that it's probably not reasonable - there's already a
community working on it with their own development process and coding
style. I don't think there's a simple answer to this but I don't agree with
your rather extreme position that all userspace tools should be kept out
of the kernel tree.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 2:47 PM, Ted Ts'o <tytso@mit.edu> wrote:
> Perf was IMHO an overreaction caused by the fact that systemtap and
> oprofile people packaged and released the sources in a way that kernel
> developers didn't like.
>
> I don't think perf should be used as a precendent that now argues that
> any new kernel utility should be moved into the kernel sources.  Does
> it make sense to move all of mount, fsck, login, etc., into the kernel
> sources?  There are far more kernel tools outside of the kernel
> sources than inside the kernel sources.

There's two overlapping questions here:

  (1) Does it make sense to merge the KVM tool to Linux kernel tree?

  (2) Does it make sense to merge userspace tools to the kernel tree?

I'm not trying to use perf to justify merging the KVM tool. However, you
seem to be arguing that it shouldn't be merged because merging
userspace tools in general doesn't make sense. That's why I brought up
the situation with perf.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 2:47 PM, Ted Ts'o <tytso@mit.edu> wrote:
> Perf was IMHO an overreaction caused by the fact that systemtap and
> oprofile people packaged and released the sources in a way that kernel
> developers didn't like.
>
> I don't think perf should be used as a precendent that now argues that
> any new kernel utility should be moved into the kernel sources.  Does
> it make sense to move all of mount, fsck, login, etc., into the kernel
> sources?  There are far more kernel tools outside of the kernel
> sources than inside the kernel sources.

There's two overlapping questions here:

  (1) Does it make sense to merge the KVM tool to Linux kernel tree?

  (2) Does it make sense to merge userspace tools to the kernel tree?

I'm not trying to use perf to justify merging the KVM tool. However, you
seem to be arguing that it shouldn't be merged because merging
userspace tools in general doesn't make sense. That's why I brought up
the situation with perf.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Ted Ts'o]

On Mon, Nov 07, 2011 at 02:42:57PM +0200, Pekka Enberg wrote:
> On Mon, Nov 7, 2011 at 2:29 PM, Ted Ts'o <tytso@mit.edu> wrote:
> > Because it's a stupid, idiotic thing to do.
> 
> The discussion is turning into whether or not linux/tools makes sense
> or not. I wish you guys would have had it before perf was merged to
> the tree.

Perf was IMHO an overreaction caused by the fact that systemtap and
oprofile people packaged and released the sources in a way that kernel
developers didn't like.

I don't think perf should be used as a precendent that now argues that
any new kernel utility should be moved into the kernel sources.  Does
it make sense to move all of mount, fsck, login, etc., into the kernel
sources?  There are far more kernel tools outside of the kernel
sources than inside the kernel sources.

    	       	       	      	       	    - Ted

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Ted Ts'o]

On Mon, Nov 07, 2011 at 02:42:57PM +0200, Pekka Enberg wrote:
> On Mon, Nov 7, 2011 at 2:29 PM, Ted Ts'o <tytso@mit.edu> wrote:
> > Because it's a stupid, idiotic thing to do.
> 
> The discussion is turning into whether or not linux/tools makes sense
> or not. I wish you guys would have had it before perf was merged to
> the tree.

Perf was IMHO an overreaction caused by the fact that systemtap and
oprofile people packaged and released the sources in a way that kernel
developers didn't like.

I don't think perf should be used as a precendent that now argues that
any new kernel utility should be moved into the kernel sources.  Does
it make sense to move all of mount, fsck, login, etc., into the kernel
sources?  There are far more kernel tools outside of the kernel
sources than inside the kernel sources.

    	       	       	      	       	    - Ted

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/07/2011 02:29 PM, Pekka Enberg wrote:
> Hi Avi,
>
> On Mon, Nov 7, 2011 at 2:26 PM, Avi Kivity <avi@redhat.com> wrote:
> >> tools/power was merged in just 2 versions ago, do you think that
> >> merging that was a mistake?
> >
> > Things like tools/power may make sense, most of the code is tied to the
> > kernel interfaces.  tools/kvm is 20k lines and is likely to be 40k+
> > lines or more before it is generally usable.  The proportion of the code
> > that talks to the kernel is quite small.
>
> So what do you think about perf then? The amount of code that talks to
> the kernel is much smaller than that of the KVM tool.

Maybe it's outgrown the kernel repo too.  Certainly something that has
perl and python integration, a TUI, and one day hopefully a GUI, doesn't
really need the kernel sources.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Ted Ts'o]

On Mon, Nov 07, 2011 at 02:29:45PM +0200, Pekka Enberg wrote:
> So what do you think about perf then? The amount of code that talks to
> the kernel is much smaller than that of the KVM tool.

I think it's a mess, because it's never clear whether perf needs to be
upgraded when I upgrade the kernel, or vice versa.  This is why I keep
harping on the interface issues.

Fortunately it seems less likely (since perf doesn't run with
privileges) that security fixes will need to be released for perf, but
if it did, given the typical regression testing requirements that many
distributions have, and given that most distro packaging tools assume
that all binaries from a single source package come from a single
version of that source package, I predict you will hear screams from
the distro release engineers.

And by the way, there are use cases, where the guest OS kernel and
root on the guest OS are not available to the untrusted users, where
the userspace KVM program would be part of the security perimeter, and
were security releases to the KVM part of the tool might very well be
necessary, and it would be unfortunate if that forced the release of
new kernel packages each time security fixes are needed to the
kvm-tool userspace.  Might kvm-tool be more secure than qemu?  Quite
possibly, given that it's going to do less than qemu.  But please note
that I've not been arguing that kvm-tool shouldn't be done; just that
it not be included in the kernel sources.

Just as sparse is not bundled into the kernel sources, for crying out
loud!

						- Ted

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Ted,

On Mon, Nov 7, 2011 at 2:29 PM, Ted Ts'o <tytso@mit.edu> wrote:
> And the same problems will exist with kvm-tool.  What if you need to
> release a new version of kvm-tool?  Does that mean that you have to
> release a new set of kernel binaries?  It's a mess, and there's a
> reason why we don't have glibc, e2fsprogs, xfsprogs, util-linux-ng,
> etc., all packaged into the kernel sources.

If we need to release a new version, patches would go through the
-stable tree just like with any other subsystem.

On Mon, Nov 7, 2011 at 2:29 PM, Ted Ts'o <tytso@mit.edu> wrote:
> Because it's a stupid, idiotic thing to do.

The discussion is turning into whether or not linux/tools makes sense
or not. I wish you guys would have had it before perf was merged to
the tree.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Ted,

On Mon, Nov 7, 2011 at 2:29 PM, Ted Ts'o <tytso@mit.edu> wrote:
> And the same problems will exist with kvm-tool.  What if you need to
> release a new version of kvm-tool?  Does that mean that you have to
> release a new set of kernel binaries?  It's a mess, and there's a
> reason why we don't have glibc, e2fsprogs, xfsprogs, util-linux-ng,
> etc., all packaged into the kernel sources.

If we need to release a new version, patches would go through the
-stable tree just like with any other subsystem.

On Mon, Nov 7, 2011 at 2:29 PM, Ted Ts'o <tytso@mit.edu> wrote:
> Because it's a stupid, idiotic thing to do.

The discussion is turning into whether or not linux/tools makes sense
or not. I wish you guys would have had it before perf was merged to
the tree.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Avi,

On Mon, Nov 7, 2011 at 2:26 PM, Avi Kivity <avi@redhat.com> wrote:
>> tools/power was merged in just 2 versions ago, do you think that
>> merging that was a mistake?
>
> Things like tools/power may make sense, most of the code is tied to the
> kernel interfaces.  tools/kvm is 20k lines and is likely to be 40k+
> lines or more before it is generally usable.  The proportion of the code
> that talks to the kernel is quite small.

So what do you think about perf then? The amount of code that talks to
the kernel is much smaller than that of the KVM tool.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Ted Ts'o]

On Mon, Nov 07, 2011 at 01:08:50PM +0100, Gerd Hoffmann wrote:
> 
> perf *is* an exception today.
> 
> It might make sense to change that.  But IMHO it only makes sense if
> there is a really broad agreement on it and other core stuff moves into
> the kernel too.  Then you'll be able to get advantages out of it.  For
> example standardizing the process to create an initramfs (using the
> userspace tools shipped with the kernel) instead of having each distro
> creating its own way.

I wish distributions had standardized on a single initramfs, sure.
But that doesn't mean that the only way to do this is to merge
userspace code into the kernel source tree.  Everybody uses fsck,
originally from the e2fsprogs source tree, and now from util-linux-ng,
and that isn't merged into the kernel sources.

And I think would be actively *harmful* to merge util-linux-ng into
the kernel sources.  For a variety of reasons, you may want to upgrade
util-linux-ng, and not the kernel, or the kernel, and not
util-linux-ng.  If you package the two sources together, it becomes
unclear what versions of the kernel will work with which versions of
util-linux-ng, and vice versa.  Suppose you need to fix a security bug
in some program that lives in util-linux-ng.  If it was bundled inside
the kernel, a distribution would now have to release a kernel source
package.  Does that mean that it will have to ship the a new set of
kernel binaries?  Or does the distribution have to ship multiple
binary packages that derive from the differently versioned source
packages?

And the same problems will exist with kvm-tool.  What if you need to
release a new version of kvm-tool?  Does that mean that you have to
release a new set of kernel binaries?  It's a mess, and there's a
reason why we don't have glibc, e2fsprogs, xfsprogs, util-linux-ng,
etc., all packaged into the kernel sources.

Because it's a stupid, idiotic thing to do.

						- Ted

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/07/2011 12:30 PM, Sasha Levin wrote:
> On Mon, Nov 7, 2011 at 12:23 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:
> >  Hi,
> >
> >> It's not just about code, it's as much about culture and development process.
> >
> > Indeed.  The BSDs have both kernel and the base system in a single
> > repository.  There are probably good reasons for (and against) it.
> >
> > In Linux we don't have that culture.  No tool (except perf) lives in the
> > kernel repo.  I fail to see why kvm-tool is that much different from
> > udev, util-linux, iproute, filesystem tools, that it should be included.
>
> tools/power was merged in just 2 versions ago, do you think that
> merging that was a mistake?

Things like tools/power may make sense, most of the code is tied to the
kernel interfaces.  tools/kvm is 20k lines and is likely to be 40k+
lines or more before it is generally usable.  The proportion of the code
that talks to the kernel is quite small.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 2:18 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:
> tools/ lacks a separation into "kernel hacker's testing+debugging
> toolbox" and "userspace tools".  It lacks proper buildsystem integration
> for the userspace tools, there is no "make tools" and also no "make
> tools_install".  Silently dropping new stuff into tools/ and expecting
> the world magically noticing isn't going to work.

No disagreement here.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 2:18 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:
> tools/ lacks a separation into "kernel hacker's testing+debugging
> toolbox" and "userspace tools".  It lacks proper buildsystem integration
> for the userspace tools, there is no "make tools" and also no "make
> tools_install".  Silently dropping new stuff into tools/ and expecting
> the world magically noticing isn't going to work.

No disagreement here.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Gerd Hoffmann]

On 11/07/11 12:44, Pekka Enberg wrote:
> On Mon, Nov 7, 2011 at 1:02 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> Indeed I do not see any advantage, since all the interfaces they use are
>> stable anyway (sysfs, msr.ko).
>>
>> If they had gone in x86info, for example, my distro (F16, not exactly
>> conservative) would have likely picked those tools up already, but it
>> didn't.
> 
> Distributing userspace tools in the kernel tree is a relatively new
> concept so it's not at all surprising distributions don't pick them up
> as quickly. That doesn't mean it's a fundamentally flawed approach,
> though.

tools/ lacks a separation into "kernel hacker's testing+debugging
toolbox" and "userspace tools".  It lacks proper buildsystem integration
for the userspace tools, there is no "make tools" and also no "make
tools_install".  Silently dropping new stuff into tools/ and expecting
the world magically noticing isn't going to work.

cheers,
  Gerd

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Gerd Hoffmann]

On 11/07/11 12:44, Pekka Enberg wrote:
> On Mon, Nov 7, 2011 at 1:02 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> Indeed I do not see any advantage, since all the interfaces they use are
>> stable anyway (sysfs, msr.ko).
>>
>> If they had gone in x86info, for example, my distro (F16, not exactly
>> conservative) would have likely picked those tools up already, but it
>> didn't.
> 
> Distributing userspace tools in the kernel tree is a relatively new
> concept so it's not at all surprising distributions don't pick them up
> as quickly. That doesn't mean it's a fundamentally flawed approach,
> though.

tools/ lacks a separation into "kernel hacker's testing+debugging
toolbox" and "userspace tools".  It lacks proper buildsystem integration
for the userspace tools, there is no "make tools" and also no "make
tools_install".  Silently dropping new stuff into tools/ and expecting
the world magically noticing isn't going to work.

cheers,
  Gerd

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Gerd Hoffmann]

On 11/07/11 12:34, Pekka Enberg wrote:
> On Mon, 7 Nov 2011, Gerd Hoffmann wrote:
>>> It's not just about code, it's as much about culture and development
>>> process.
>>
>> Indeed.  The BSDs have both kernel and the base system in a single
>> repository.  There are probably good reasons for (and against) it.
>>
>> In Linux we don't have that culture.  No tool (except perf) lives in the
>> kernel repo.  I fail to see why kvm-tool is that much different from
>> udev, util-linux, iproute, filesystem tools, that it should be included.
> 
> You seem to think perf is an exception - I think it's going to be the
> future norm for userspace components that are very close to the kernel.

perf *is* an exception today.

It might make sense to change that.  But IMHO it only makes sense if
there is a really broad agreement on it and other core stuff moves into
the kernel too.  Then you'll be able to get advantages out of it.  For
example standardizing the process to create an initramfs (using the
userspace tools shipped with the kernel) instead of having each distro
creating its own way.

I somehow doubt we'll see such an broad agreement though.  Most people
seem to be happy with the current model.  There is a reason why the
klibc + early-userspace-in-kernel-tree project died in the end ...

cheers,
  Gerd

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Kevin Wolf]

Am 07.11.2011 12:38, schrieb Pekka Enberg:
> On Mon, 7 Nov 2011, Kevin Wolf wrote:
>> Makes it a lot less hackable for me unless you want to restrict the set
>> of potential developers to Linux kernel developers...
> 
> We're not restricting potential developers to Linux kernel folks. We're 
> making it easy for them because we believe that the KVM tool is a 
> userspace component that requires the kind of low-level knowledge Linux 
> kernel developers have.
> 
> I think you're looking at the KVM tool with your QEMU glasses on without 
> realizing that there's no point in comparing the two: we only support 
> Linux on Linux and we avoid hardware emulation as much as possible. So 
> what makes sense for QEMU, doesn't necessarily translate to the KVM tool 
> project.

I'm not comparing anything. I'm not even referring to the virtualization
functionality of it. It could be doing anything else and it wouldn't
make a difference.

For KVM tool I am not much more than a mere user. Trying it out was
tedious for me, as it is for anyone else who isn't a kernel developer.
That's all I'm saying.

Making things easier for some kernel developers but ignoring that at the
same time it makes things harder for users I consider a not so clever
move. Just wanted to point that out; feel free to ignore it, your
priorities are probably different.

Kevin

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Ingo Molnar]

* Pekka Enberg <penberg@cs.helsinki.fi> wrote:

> On Mon, 7 Nov 2011, Gerd Hoffmann wrote:
> >>It's not just about code, it's as much about culture and development process.
> >
> >Indeed.  The BSDs have both kernel and the base system in a single
> >repository.  There are probably good reasons for (and against) it.
> >
> > In Linux we don't have that culture.  No tool (except perf) lives 
> > in the kernel repo.  I fail to see why kvm-tool is that much 
> > different from udev, util-linux, iproute, filesystem tools, that 
> > it should be included.
> 
> You seem to think perf is an exception - I think it's going to be 
> the future norm for userspace components that are very close to the 
> kernel. That's in fact what Ingo was arguing for when he suggested 
> QEMU to be merged to the kernel tree.

Yep, and the answer i got from the Qemu folks when i suggested that 
merge was a polite "buzz off", along the lines of: "We don't want to 
do that, but feel free to write your own tool, leave Qemu alone."

Now that people have done exactly that some Qemu folks not only have 
changed their objection from "write your own tool" to "erm, write 
your own tool but do it the way *we* prefer you to do it" - they also 
started contributing *against* the KVM tool with predictable, once 
every 3 months objections against its upstream merge...

That's not very nice and not very constructive.

The only valid technical objection against tools/kvm/ that i can see 
would be that it's not useful enough yet for the upstream kernel 
versus other tools such as Qemu. In all fairness i think we might 
still be at that early stage of the project but it's clearly 
progressing very rapidly and i'm already using it on a daily basis 
for my own kernel testing purposes. During the Kernel Summit that's 
how i tested contemporary kernels on contemporary user-space 
remotely, without having to risk a physical reboot.

Thanks,

	Ingo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Ingo Molnar]

* Pekka Enberg <penberg@cs.helsinki.fi> wrote:

> On Mon, 7 Nov 2011, Gerd Hoffmann wrote:
> >>It's not just about code, it's as much about culture and development process.
> >
> >Indeed.  The BSDs have both kernel and the base system in a single
> >repository.  There are probably good reasons for (and against) it.
> >
> > In Linux we don't have that culture.  No tool (except perf) lives 
> > in the kernel repo.  I fail to see why kvm-tool is that much 
> > different from udev, util-linux, iproute, filesystem tools, that 
> > it should be included.
> 
> You seem to think perf is an exception - I think it's going to be 
> the future norm for userspace components that are very close to the 
> kernel. That's in fact what Ingo was arguing for when he suggested 
> QEMU to be merged to the kernel tree.

Yep, and the answer i got from the Qemu folks when i suggested that 
merge was a polite "buzz off", along the lines of: "We don't want to 
do that, but feel free to write your own tool, leave Qemu alone."

Now that people have done exactly that some Qemu folks not only have 
changed their objection from "write your own tool" to "erm, write 
your own tool but do it the way *we* prefer you to do it" - they also 
started contributing *against* the KVM tool with predictable, once 
every 3 months objections against its upstream merge...

That's not very nice and not very constructive.

The only valid technical objection against tools/kvm/ that i can see 
would be that it's not useful enough yet for the upstream kernel 
versus other tools such as Qemu. In all fairness i think we might 
still be at that early stage of the project but it's clearly 
progressing very rapidly and i'm already using it on a daily basis 
for my own kernel testing purposes. During the Kernel Summit that's 
how i tested contemporary kernels on contemporary user-space 
remotely, without having to risk a physical reboot.

Thanks,

	Ingo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 1:02 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Indeed I do not see any advantage, since all the interfaces they use are
> stable anyway (sysfs, msr.ko).
>
> If they had gone in x86info, for example, my distro (F16, not exactly
> conservative) would have likely picked those tools up already, but it
> didn't.

Distributing userspace tools in the kernel tree is a relatively new
concept so it's not at all surprising distributions don't pick them up
as quickly. That doesn't mean it's a fundamentally flawed approach,
though.

Also, I'm mostly interested in defending the KVM tool, so I'd prefer
not to argue whether or not carrying userspace code in the kernel tree
makes sense or not. The fact is that Linux is already doing it and I
think the only relevant question is whether or not the KVM tool
qualifies. I obviously think the answer is yes.

                               Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 1:02 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Indeed I do not see any advantage, since all the interfaces they use are
> stable anyway (sysfs, msr.ko).
>
> If they had gone in x86info, for example, my distro (F16, not exactly
> conservative) would have likely picked those tools up already, but it
> didn't.

Distributing userspace tools in the kernel tree is a relatively new
concept so it's not at all surprising distributions don't pick them up
as quickly. That doesn't mean it's a fundamentally flawed approach,
though.

Also, I'm mostly interested in defending the KVM tool, so I'd prefer
not to argue whether or not carrying userspace code in the kernel tree
makes sense or not. The fact is that Linux is already doing it and I
think the only relevant question is whether or not the KVM tool
qualifies. I obviously think the answer is yes.

                               Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, 7 Nov 2011, Kevin Wolf wrote:
> Makes it a lot less hackable for me unless you want to restrict the set
> of potential developers to Linux kernel developers...

We're not restricting potential developers to Linux kernel folks. We're 
making it easy for them because we believe that the KVM tool is a 
userspace component that requires the kind of low-level knowledge Linux 
kernel developers have.

I think you're looking at the KVM tool with your QEMU glasses on without 
realizing that there's no point in comparing the two: we only support 
Linux on Linux and we avoid hardware emulation as much as possible. So 
what makes sense for QEMU, doesn't necessarily translate to the KVM tool 
project.

 			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, 7 Nov 2011, Gerd Hoffmann wrote:
>> It's not just about code, it's as much about culture and development process.
>
> Indeed.  The BSDs have both kernel and the base system in a single
> repository.  There are probably good reasons for (and against) it.
>
> In Linux we don't have that culture.  No tool (except perf) lives in the
> kernel repo.  I fail to see why kvm-tool is that much different from
> udev, util-linux, iproute, filesystem tools, that it should be included.

You seem to think perf is an exception - I think it's going to be the 
future norm for userspace components that are very close to the kernel. 
That's in fact what Ingo was arguing for when he suggested QEMU to be 
merged to the kernel tree.

 			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/07/2011 11:30 AM, Sasha Levin wrote:
> >  In Linux we don't have that culture.  No tool (except perf) lives in the
> >  kernel repo.  I fail to see why kvm-tool is that much different from
> >  udev, util-linux, iproute, filesystem tools, that it should be included.
>
> tools/power was merged in just 2 versions ago, do you think that
> merging that was a mistake?

Indeed I do not see any advantage, since all the interfaces they use are 
stable anyway (sysfs, msr.ko).

If they had gone in x86info, for example, my distro (F16, not exactly 
conservative) would have likely picked those tools up already, but it 
didn't.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/07/2011 11:30 AM, Sasha Levin wrote:
> >  In Linux we don't have that culture.  No tool (except perf) lives in the
> >  kernel repo.  I fail to see why kvm-tool is that much different from
> >  udev, util-linux, iproute, filesystem tools, that it should be included.
>
> tools/power was merged in just 2 versions ago, do you think that
> merging that was a mistake?

Indeed I do not see any advantage, since all the interfaces they use are 
stable anyway (sysfs, msr.ko).

If they had gone in x86info, for example, my distro (F16, not exactly 
conservative) would have likely picked those tools up already, but it 
didn't.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Kevin Wolf]

Am 06.11.2011 19:31, schrieb Ted Ts'o:
> On Sun, Nov 06, 2011 at 11:08:10AM -0600, Anthony Liguori wrote:
>> I'm quite happy with KVM tool and hope they continue working on it.
>> My only real wish is that they wouldn't copy QEMU so much and would
>> try bolder things that are fundamentally different from QEMU.
> 
> My big wish is that they don't try to merge the KVM tool into the
> kernel code.  It's a separate userspace project, and there's no reason
> for it to be bundled with kernel code.  It just makes the kernel
> sources larger. 

In fact, the reverse is true as well: It makes kvm-tool's sources
larger. Instead on just cloning a small repository I need to clone the
whole kernel repository, even though I'm not a kernel developer and
don't intend to touch anything but tools/kvm.

Not too bad for me as I have a kernel repository lying around anyway and
I can share most of the content, but there are people who don't. Still,
having an additional 1.2 GB repository just for ~1 MB in which I'm
really interested doesn't make me too happy. And dealing with a huge
repository also means that even git becomes slower (which means, I had
to turn off some functionality for my shell prompt in this repo, as I
didn't like waiting for much more than a second or two)

Makes it a lot less hackable for me unless you want to restrict the set
of potential developers to Linux kernel developers...

Kevin

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Sasha Levin]

On Mon, Nov 7, 2011 at 12:23 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:
>  Hi,
>
>> It's not just about code, it's as much about culture and development process.
>
> Indeed.  The BSDs have both kernel and the base system in a single
> repository.  There are probably good reasons for (and against) it.
>
> In Linux we don't have that culture.  No tool (except perf) lives in the
> kernel repo.  I fail to see why kvm-tool is that much different from
> udev, util-linux, iproute, filesystem tools, that it should be included.

tools/power was merged in just 2 versions ago, do you think that
merging that was a mistake?

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Gerd Hoffmann]

  Hi,

> It's not just about code, it's as much about culture and development process.

Indeed.  The BSDs have both kernel and the base system in a single
repository.  There are probably good reasons for (and against) it.

In Linux we don't have that culture.  No tool (except perf) lives in the
kernel repo.  I fail to see why kvm-tool is that much different from
udev, util-linux, iproute, filesystem tools, that it should be included.

cheers,
  Gerd

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Gerd Hoffmann]

  Hi,

> It's not just about code, it's as much about culture and development process.

Indeed.  The BSDs have both kernel and the base system in a single
repository.  There are probably good reasons for (and against) it.

In Linux we don't have that culture.  No tool (except perf) lives in the
kernel repo.  I fail to see why kvm-tool is that much different from
udev, util-linux, iproute, filesystem tools, that it should be included.

cheers,
  Gerd

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 12:11 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:
> No support for booting from CDROM.
> No support for booting from Network.
> Thus no way to install a new guest image.

Sure. It's a pain point which we need to fix.

On Mon, Nov 7, 2011 at 12:11 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:
> Booting an existing qcow2 guest image failed, the guest started throwing
> I/O errors.  And even to try that I had to manually extract the kernel
> and initrd images from the guest.  Maybe you should check with the Xen
> guys, they have a funky 'pygrub' which sort-of automates the
> copy-kernel-from-guest-image process.

QCOW2 support is experimental. The I/O errors are caused by forced
read-only mode.

On Mon, Nov 7, 2011 at 12:11 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:
> Booting the host kernel failed too.  Standard distro kernel.  The virtio
> bits are modular, not statically compiled into the kernel.  kvm tool
> can't handle that.

I think we have some support for booting modular distro kernels too if
you tell KVM tool where to find initrd. It sucks out-of-the-box though
because nobody seems to be using it.

On Mon, Nov 7, 2011 at 12:11 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:
> You have to build your own kernel and make sure you flip the correct
> config bits, then you can boot it to a shell prompt.  Trying anything
> else just doesn't work today ...

What can I say? Patches welcome? :-)

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Gerd Hoffmann]

  Hi,

> "Usable" - I've tried kvm-tool several times and still (today) fail to
> get a standard SUSE image (with a kernel I have to compile and provide
> separately...) up and running *). Likely a user mistake, but none that
> is very obvious. At least to me.

Same here.

No support for booting from CDROM.
No support for booting from Network.
Thus no way to install a new guest image.

Booting an existing qcow2 guest image failed, the guest started throwing
I/O errors.  And even to try that I had to manually extract the kernel
and initrd images from the guest.  Maybe you should check with the Xen
guys, they have a funky 'pygrub' which sort-of automates the
copy-kernel-from-guest-image process.

Booting the host kernel failed too.  Standard distro kernel.  The virtio
bits are modular, not statically compiled into the kernel.  kvm tool
can't handle that.

You have to build your own kernel and make sure you flip the correct
config bits, then you can boot it to a shell prompt.  Trying anything
else just doesn't work today ...

cheers,
  Gerd

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Gerd Hoffmann]

  Hi,

> "Usable" - I've tried kvm-tool several times and still (today) fail to
> get a standard SUSE image (with a kernel I have to compile and provide
> separately...) up and running *). Likely a user mistake, but none that
> is very obvious. At least to me.

Same here.

No support for booting from CDROM.
No support for booting from Network.
Thus no way to install a new guest image.

Booting an existing qcow2 guest image failed, the guest started throwing
I/O errors.  And even to try that I had to manually extract the kernel
and initrd images from the guest.  Maybe you should check with the Xen
guys, they have a funky 'pygrub' which sort-of automates the
copy-kernel-from-guest-image process.

Booting the host kernel failed too.  Standard distro kernel.  The virtio
bits are modular, not statically compiled into the kernel.  kvm tool
can't handle that.

You have to build your own kernel and make sure you flip the correct
config bits, then you can boot it to a shell prompt.  Trying anything
else just doesn't work today ...

cheers,
  Gerd

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On 11/07/2011 09:45 AM, Pekka Enberg wrote:
>>> Specifications matter much more than working code.  Quirks are a fact
>>> of life but should always come second.
>>
>> To quote Linus:
>>
>>   And I have seen _lots_ of total crap work that was based on specs. It's
>> _the_ single worst way to write software, because it by definition means
>>   that the software was written to match theory, not reality.

On Mon, Nov 7, 2011 at 10:52 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> All generalizations are false.

What is that supposed to mean? You claimed we're "doing it wrong" and
I explained you why we are doing it the way we are.

Really, the way we do things in the KVM tool is not a bug, it's a feature.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On 11/07/2011 09:45 AM, Pekka Enberg wrote:
>>> Specifications matter much more than working code.  Quirks are a fact
>>> of life but should always come second.
>>
>> To quote Linus:
>>
>>   And I have seen _lots_ of total crap work that was based on specs. It's
>> _the_ single worst way to write software, because it by definition means
>>   that the software was written to match theory, not reality.

On Mon, Nov 7, 2011 at 10:52 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> All generalizations are false.

What is that supposed to mean? You claimed we're "doing it wrong" and
I explained you why we are doing it the way we are.

Really, the way we do things in the KVM tool is not a bug, it's a feature.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/07/2011 09:45 AM, Pekka Enberg wrote:
>
>> Specifications matter much more than working code.  Quirks are a fact
>> of life but should always come second.
>
> To quote Linus:
>
>    And I have seen _lots_ of total crap work that was based on specs. It's
> _the_ single worst way to write software, because it by definition means
>    that the software was written to match theory, not reality.

All generalizations are false.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/07/2011 09:45 AM, Pekka Enberg wrote:
>
>> Specifications matter much more than working code.  Quirks are a fact
>> of life but should always come second.
>
> To quote Linus:
>
>    And I have seen _lots_ of total crap work that was based on specs. It's
> _the_ single worst way to write software, because it by definition means
>    that the software was written to match theory, not reality.

All generalizations are false.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 661 bytes --]

On 11/07/2011 09:09 AM, Pekka Enberg wrote:
>> We are obviously also using specifications but as you damn well should
>> know, specifications don't matter nearly as much as working code.

On Mon, 7 Nov 2011, Paolo Bonzini wrote:
> Specifications matter much more than working code.  Quirks are a fact of life 
> but should always come second.

To quote Linus:

   And I have seen _lots_ of total crap work that was based on specs. It's
   _the_ single worst way to write software, because it by definition means
   that the software was written to match theory, not reality.

[ http://kerneltrap.org/node/5725 ]

So no, I don't agree with you at all.

 			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 661 bytes --]

On 11/07/2011 09:09 AM, Pekka Enberg wrote:
>> We are obviously also using specifications but as you damn well should
>> know, specifications don't matter nearly as much as working code.

On Mon, 7 Nov 2011, Paolo Bonzini wrote:
> Specifications matter much more than working code.  Quirks are a fact of life 
> but should always come second.

To quote Linus:

   And I have seen _lots_ of total crap work that was based on specs. It's
   _the_ single worst way to write software, because it by definition means
   that the software was written to match theory, not reality.

[ http://kerneltrap.org/node/5725 ]

So no, I don't agree with you at all.

 			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/07/2011 09:09 AM, Pekka Enberg wrote:
> We are obviously also using specifications but as you damn well should
> know, specifications don't matter nearly as much as working code.

Specifications matter much more than working code.  Quirks are a fact of 
life but should always come second.

To bring you an example from the kernel, there is a very boring list of 
"PCI quirks" and a lot of code for "PCI specs", not the other way round.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/07/2011 09:09 AM, Pekka Enberg wrote:
> We are obviously also using specifications but as you damn well should
> know, specifications don't matter nearly as much as working code.

Specifications matter much more than working code.  Quirks are a fact of 
life but should always come second.

To bring you an example from the kernel, there is a very boring list of 
"PCI quirks" and a lot of code for "PCI specs", not the other way round.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 10:00 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> (BTW, I'm also convinced like Ted that not having a defined perf ABI might
> have made sense in the beginning, but it has now devolved into bad software
> engineering practice).

I'm not a perf maintainer so I don't know what the situation with wrt.
ABI breakage is. Your or Ted's comments don't match my assumptions or
experience, though.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 10:00 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> (BTW, I'm also convinced like Ted that not having a defined perf ABI might
> have made sense in the beginning, but it has now devolved into bad software
> engineering practice).

I'm not a perf maintainer so I don't know what the situation with wrt.
ABI breakage is. Your or Ted's comments don't match my assumptions or
experience, though.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 10:00 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> No, having the source code in Linux kernel tree is perfectly useless for the
> exceptional case, and forces you to go through extra hoops to build only one
> component.  Small hoops such as adding "-- tools/kvm" to "git bisect start"
> perhaps, but still hoops that aren't traded for a practical advantage.  You
> keep saying "oh things have been so much better" because "it's so close to
> the kernel" and "it worked so great for perf", but you haven't brought any
> practical example that we can stare at in admiration.

The _practical example_ is the working software in tools/kvm!

>> I have no idea why you're trying to convince me that it doesn't matter.
>
> I'm not trying to convince you that it doesn't matter, I'm trying to
> convince you that it doesn't *make sense*.
>
>> It's a hypervisor that implements virtio drivers, serial
>> emulation, and mini-BIOS.
>
> ... all of which have a spec against which you should be working.  Save
> perhaps for the mini-BIOS, if you develop against the kernel source rather
> than the spec you're doing it *wrong*.  Very wrong.  But you've been told
> this many times already.

I have zero interest in arguing with you about something you have no
practical experience on. I've tried both out-of-tree and in-tree
development for the KVM tool and I can tell you the latter is much
more productive environment.

We are obviously also using specifications but as you damn well should
know, specifications don't matter nearly as much as working code.
That's why it's important to have easy access to both.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 10:00 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> No, having the source code in Linux kernel tree is perfectly useless for the
> exceptional case, and forces you to go through extra hoops to build only one
> component.  Small hoops such as adding "-- tools/kvm" to "git bisect start"
> perhaps, but still hoops that aren't traded for a practical advantage.  You
> keep saying "oh things have been so much better" because "it's so close to
> the kernel" and "it worked so great for perf", but you haven't brought any
> practical example that we can stare at in admiration.

The _practical example_ is the working software in tools/kvm!

>> I have no idea why you're trying to convince me that it doesn't matter.
>
> I'm not trying to convince you that it doesn't matter, I'm trying to
> convince you that it doesn't *make sense*.
>
>> It's a hypervisor that implements virtio drivers, serial
>> emulation, and mini-BIOS.
>
> ... all of which have a spec against which you should be working.  Save
> perhaps for the mini-BIOS, if you develop against the kernel source rather
> than the spec you're doing it *wrong*.  Very wrong.  But you've been told
> this many times already.

I have zero interest in arguing with you about something you have no
practical experience on. I've tried both out-of-tree and in-tree
development for the KVM tool and I can tell you the latter is much
more productive environment.

We are obviously also using specifications but as you damn well should
know, specifications don't matter nearly as much as working code.
That's why it's important to have easy access to both.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/06/2011 09:17 PM, Pekka Enberg wrote:
> >  No.  I want to try new tool/old kernel and old tool/new kernel (kernel can
> >  be either guest or host, depending on the nature of the bug), and then
> >  bisect just one.  (*) And that's the exceptional case, and only KVM tool
> >  developers really should have the need to do that.
>
> Exactly - having the source code in Linux kernel tree covers the
> "exceptional case" where we're unsure which part of the equation broke
> things (which are btw the nasties issues we've had so far).

No, having the source code in Linux kernel tree is perfectly useless for 
the exceptional case, and forces you to go through extra hoops to build 
only one component.  Small hoops such as adding "-- tools/kvm" to "git 
bisect start" perhaps, but still hoops that aren't traded for a 
practical advantage.  You keep saying "oh things have been so much 
better" because "it's so close to the kernel" and "it worked so great 
for perf", but you haven't brought any practical example that we can 
stare at in admiration.

(BTW, I'm also convinced like Ted that not having a defined perf ABI 
might have made sense in the beginning, but it has now devolved into bad 
software engineering practice).

> I have no idea why you're trying to convince me that it doesn't matter.

I'm not trying to convince you that it doesn't matter, I'm trying to 
convince you that it doesn't *make sense*.

> It's a hypervisor that implements virtio drivers, serial
> emulation, and mini-BIOS.

... all of which have a spec against which you should be working.  Save 
perhaps for the mini-BIOS, if you develop against the kernel source 
rather than the spec you're doing it *wrong*.  Very wrong.  But you've 
been told this many times already.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/06/2011 09:17 PM, Pekka Enberg wrote:
> >  No.  I want to try new tool/old kernel and old tool/new kernel (kernel can
> >  be either guest or host, depending on the nature of the bug), and then
> >  bisect just one.  (*) And that's the exceptional case, and only KVM tool
> >  developers really should have the need to do that.
>
> Exactly - having the source code in Linux kernel tree covers the
> "exceptional case" where we're unsure which part of the equation broke
> things (which are btw the nasties issues we've had so far).

No, having the source code in Linux kernel tree is perfectly useless for 
the exceptional case, and forces you to go through extra hoops to build 
only one component.  Small hoops such as adding "-- tools/kvm" to "git 
bisect start" perhaps, but still hoops that aren't traded for a 
practical advantage.  You keep saying "oh things have been so much 
better" because "it's so close to the kernel" and "it worked so great 
for perf", but you haven't brought any practical example that we can 
stare at in admiration.

(BTW, I'm also convinced like Ted that not having a defined perf ABI 
might have made sense in the beginning, but it has now devolved into bad 
software engineering practice).

> I have no idea why you're trying to convince me that it doesn't matter.

I'm not trying to convince you that it doesn't matter, I'm trying to 
convince you that it doesn't *make sense*.

> It's a hypervisor that implements virtio drivers, serial
> emulation, and mini-BIOS.

... all of which have a spec against which you should be working.  Save 
perhaps for the mini-BIOS, if you develop against the kernel source 
rather than the spec you're doing it *wrong*.  Very wrong.  But you've 
been told this many times already.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 12:08 AM, Frank Ch. Eigler <fche@redhat.com> wrote:
>> [...]  We don't want to be different, we want to make the barrier of
>> entry low.
>
> When has the barrier of entry into the kernel ever been "low"
> for anyone not already working in the kernel?

What's your point? Working on the KVM tool requires knowledge of the
Linux kernel.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Mon, Nov 7, 2011 at 12:08 AM, Frank Ch. Eigler <fche@redhat.com> wrote:
>> [...]  We don't want to be different, we want to make the barrier of
>> entry low.
>
> When has the barrier of entry into the kernel ever been "low"
> for anyone not already working in the kernel?

What's your point? Working on the KVM tool requires knowledge of the
Linux kernel.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, 6 Nov 2011, Ted Ts'o wrote:
> The only excuse I can see is a hope to make random changes to the
> kernel and userspace tools without having to worry about compatibility
> problems, which is an argument I've seen with perf (that you have to
> use the same version of perf as the kernel version, which to me is bad
> software engineering).  And that's why I pointed out that you can't do
> that with KVM, since we have out-of-tree userspace users, namely
> qemu-kvm.

I've never heard ABI incompatibility used as an argument for perf. Ingo?

As for the KVM tool, merging has never been about being able to do ABI 
incompatible changes and never will be. I'm still surprised you even 
brought this up because I've always been one to _complain_ about people 
breaking the ABI - not actually breaking it (at least on purpose).

 			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Anthony Liguori]

On 11/06/2011 12:09 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 7:08 PM, Anthony Liguori<anthony@codemonkey.ws>  wrote:
>> I'm quite happy with KVM tool and hope they continue working on it.  My only
>> real wish is that they wouldn't copy QEMU so much and would try bolder
>> things that are fundamentally different from QEMU.
>
> Hey, right now our only source of crazy ideas is Ingo and I think he's
> actually a pretty conservative guy when it comes to technology. Avi
> has expressed some crazy ideas in the past but they require switching
> away from C and that's not something we're interested in doing. ;-)

Just a couple random suggestions:

- Drop SDL/VNC.  Make a proper Cairo GUI with a full blown GTK interface.  Don't 
rely on virt-manager for this.  Not that I have anything against virt-manager 
but there are many layers between you and the end GUI if you go that route.

- Sandbox the device model from day #1.  The size of the Linux kernel interface 
is pretty huge and as a hypervisor, it's the biggest place for improvement from 
a security perspective.  We're going to do sandboxing in QEMU, but it's going to 
be difficult.  It would be much easier for you given where you're at.

Regards,

Anthony Liguori

>
>                          Pekka
>

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Frank Ch. Eigler]

$	<CAOJsxLFCjkAK7Lw4M15G44k11zrcF7tnu9yMbiQYDBNZr+83tg@mail.gmail.com>
From: fche@redhat.com (Frank Ch. Eigler)
Date: Sun, 06 Nov 2011 17:08:48 -0500
In-Reply-To: <CAOJsxLFCjkAK7Lw4M15G44k11zrcF7tnu9yMbiQYDBNZr+83tg@mail.gmail.com> (Pekka Enberg's message of "Sun, 6 Nov 2011 20:05:45 +0200")
Message-ID: <y0mhb2g6gzz.fsf@fche.csb>
User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.4 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii


Pekka Enberg <penberg@kernel.org> writes:

> [...]  We don't want to be different, we want to make the barrier of
> entry low.

When has the barrier of entry into the kernel ever been "low"
for anyone not already working in the kernel?

- FChE

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Frank Ch. Eigler]

$	<CAOJsxLFCjkAK7Lw4M15G44k11zrcF7tnu9yMbiQYDBNZr+83tg@mail.gmail.com>
From: fche@redhat.com (Frank Ch. Eigler)
Date: Sun, 06 Nov 2011 17:08:48 -0500
In-Reply-To: <CAOJsxLFCjkAK7Lw4M15G44k11zrcF7tnu9yMbiQYDBNZr+83tg@mail.gmail.com> (Pekka Enberg's message of "Sun, 6 Nov 2011 20:05:45 +0200")
Message-ID: <y0mhb2g6gzz.fsf@fche.csb>
User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.4 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii


Pekka Enberg <penberg@kernel.org> writes:

> [...]  We don't want to be different, we want to make the barrier of
> entry low.

When has the barrier of entry into the kernel ever been "low"
for anyone not already working in the kernel?

- FChE

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 10:01 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Nothing, but I'm just giving you *strong* hints that a submodule or a merged
> tool is the wrong solution, and the histories of kernel and tool should be
> kept separate.

And btw, I don't really understand what you're trying to accomplish
with this line of reasoning. We've tried both separate and shared
repository and the latter is much better from development point of
view.

This is not some random userspace project that uses the kernel system
calls. It's a hypervisor that implements virtio drivers, serial
emulation, and mini-BIOS. It's very close to the kernel which is why
it's such a good fit with the kernel tree.

I'd actually be willing to argue that from purely technical point of
view, KVM tool makes much more sense to have in the kernel tree than
perf does.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 10:01 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Nothing, but I'm just giving you *strong* hints that a submodule or a merged
> tool is the wrong solution, and the histories of kernel and tool should be
> kept separate.

And btw, I don't really understand what you're trying to accomplish
with this line of reasoning. We've tried both separate and shared
repository and the latter is much better from development point of
view.

This is not some random userspace project that uses the kernel system
calls. It's a hypervisor that implements virtio drivers, serial
emulation, and mini-BIOS. It's very close to the kernel which is why
it's such a good fit with the kernel tree.

I'd actually be willing to argue that from purely technical point of
view, KVM tool makes much more sense to have in the kernel tree than
perf does.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 10:01 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> If you're bisecting breakage that can be in the guest kernel or the
>> KVM tool, you'd want to build both.
>
> No.  I want to try new tool/old kernel and old tool/new kernel (kernel can
> be either guest or host, depending on the nature of the bug), and then
> bisect just one.  (*) And that's the exceptional case, and only KVM tool
> developers really should have the need to do that.

Exactly - having the source code in Linux kernel tree covers the
"exceptional case" where we're unsure which part of the equation broke
things (which are btw the nasties issues we've had so far). I have no
idea why you're trying to convince me that it doesn't matter. You can
bisect only one of the components in isolation just fine.

On Sun, Nov 6, 2011 at 10:01 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> What would prevent you from using a newer KVM tool with an older kernel?
>
> Nothing, but I'm just giving you *strong* hints that a submodule or a merged
> tool is the wrong solution, and the histories of kernel and tool should be
> kept separate.
>
> More clearly: for its supposedly intended usage, namely testing development
> kernels in a *guest*, KVM tool will generally not run on the exact *host*
> kernel that is in the tree it lives with.  Almost never, in fact.  Unlike
> perf, if you want to test multiple guest kernels you should never need to
> rebuild KVM tool!
>
> This is the main argument as to whether or not to merge the tool.  Would the
> integration of the *build* make sense or not?  Assume you adapt the ktest
> script to make both the KVM tool and the kernel, and test the latter using
> the former.  Your host kernel never changes, and yet you introduce a new
> variable in your testing.  That complicates things, it doesn't simplify
> them.

I don't understand what trying to say. There's no requirement to build
the KVM tool if you're bisecting a guest kernel.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 10:01 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> If you're bisecting breakage that can be in the guest kernel or the
>> KVM tool, you'd want to build both.
>
> No.  I want to try new tool/old kernel and old tool/new kernel (kernel can
> be either guest or host, depending on the nature of the bug), and then
> bisect just one.  (*) And that's the exceptional case, and only KVM tool
> developers really should have the need to do that.

Exactly - having the source code in Linux kernel tree covers the
"exceptional case" where we're unsure which part of the equation broke
things (which are btw the nasties issues we've had so far). I have no
idea why you're trying to convince me that it doesn't matter. You can
bisect only one of the components in isolation just fine.

On Sun, Nov 6, 2011 at 10:01 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> What would prevent you from using a newer KVM tool with an older kernel?
>
> Nothing, but I'm just giving you *strong* hints that a submodule or a merged
> tool is the wrong solution, and the histories of kernel and tool should be
> kept separate.
>
> More clearly: for its supposedly intended usage, namely testing development
> kernels in a *guest*, KVM tool will generally not run on the exact *host*
> kernel that is in the tree it lives with.  Almost never, in fact.  Unlike
> perf, if you want to test multiple guest kernels you should never need to
> rebuild KVM tool!
>
> This is the main argument as to whether or not to merge the tool.  Would the
> integration of the *build* make sense or not?  Assume you adapt the ktest
> script to make both the KVM tool and the kernel, and test the latter using
> the former.  Your host kernel never changes, and yet you introduce a new
> variable in your testing.  That complicates things, it doesn't simplify
> them.

I don't understand what trying to say. There's no requirement to build
the KVM tool if you're bisecting a guest kernel.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/06/2011 08:17 PM, Pekka Enberg wrote:
>> >  But I'm pretty certain that, when testing 3.2 with KVM tool in a couple of
>> >  years, I want all the shining new features you added in this time; I don't
>> >  want the old end-2011 code.  Same if I'm bisecting kernels, I don't want to
>> >  build KVM tool once per bisection cycle, do I?
>
> If you're bisecting breakage that can be in the guest kernel or the
> KVM tool, you'd want to build both.

No.  I want to try new tool/old kernel and old tool/new kernel (kernel 
can be either guest or host, depending on the nature of the bug), and 
then bisect just one.  (*) And that's the exceptional case, and only KVM 
tool developers really should have the need to do that.

   (*) Not coincidentially, that's what git bisect does when HEAD is
       a merge of two unrelated histories.

> What would prevent you from using a newer KVM tool with an older kernel?

Nothing, but I'm just giving you *strong* hints that a submodule or a 
merged tool is the wrong solution, and the histories of kernel and tool 
should be kept separate.

More clearly: for its supposedly intended usage, namely testing 
development kernels in a *guest*, KVM tool will generally not run on the 
exact *host* kernel that is in the tree it lives with.  Almost never, in 
fact.  Unlike perf, if you want to test multiple guest kernels you 
should never need to rebuild KVM tool!

This is the main argument as to whether or not to merge the tool.  Would 
the integration of the *build* make sense or not?  Assume you adapt the 
ktest script to make both the KVM tool and the kernel, and test the 
latter using the former.  Your host kernel never changes, and yet you 
introduce a new variable in your testing.  That complicates things, it 
doesn't simplify them.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/06/2011 08:17 PM, Pekka Enberg wrote:
>> >  But I'm pretty certain that, when testing 3.2 with KVM tool in a couple of
>> >  years, I want all the shining new features you added in this time; I don't
>> >  want the old end-2011 code.  Same if I'm bisecting kernels, I don't want to
>> >  build KVM tool once per bisection cycle, do I?
>
> If you're bisecting breakage that can be in the guest kernel or the
> KVM tool, you'd want to build both.

No.  I want to try new tool/old kernel and old tool/new kernel (kernel 
can be either guest or host, depending on the nature of the bug), and 
then bisect just one.  (*) And that's the exceptional case, and only KVM 
tool developers really should have the need to do that.

   (*) Not coincidentially, that's what git bisect does when HEAD is
       a merge of two unrelated histories.

> What would prevent you from using a newer KVM tool with an older kernel?

Nothing, but I'm just giving you *strong* hints that a submodule or a 
merged tool is the wrong solution, and the histories of kernel and tool 
should be kept separate.

More clearly: for its supposedly intended usage, namely testing 
development kernels in a *guest*, KVM tool will generally not run on the 
exact *host* kernel that is in the tree it lives with.  Almost never, in 
fact.  Unlike perf, if you want to test multiple guest kernels you 
should never need to rebuild KVM tool!

This is the main argument as to whether or not to merge the tool.  Would 
the integration of the *build* make sense or not?  Assume you adapt the 
ktest script to make both the KVM tool and the kernel, and test the 
latter using the former.  Your host kernel never changes, and yet you 
introduce a new variable in your testing.  That complicates things, it 
doesn't simplify them.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 9:14 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> GStreamer (V4L), RTSAdmin (LIO target), sg3_utils, trousers all are out of
> tree, and nobody of their authors is even thinking of doing all this
> brouhaha to get merged into Linus's tree.

We'd be the first subsystem to use the download script thing Alex suggested.

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 9:14 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> GStreamer (V4L), RTSAdmin (LIO target), sg3_utils, trousers all are out of
> tree, and nobody of their authors is even thinking of doing all this
> brouhaha to get merged into Linus's tree.

We'd be the first subsystem to use the download script thing Alex suggested.

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 9:11 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> I really don't see the point in doing that. We want to be part of
>> regular kernel history and release cycle.
>
> But I'm pretty certain that, when testing 3.2 with KVM tool in a couple of
> years, I want all the shining new features you added in this time; I don't
> want the old end-2011 code.  Same if I'm bisecting kernels, I don't want to
> build KVM tool once per bisection cycle, do I?

If you're bisecting breakage that can be in the guest kernel or the
KVM tool, you'd want to build both.

What would prevent you from using a newer KVM tool with an older kernel?

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/06/2011 07:05 PM, Pekka Enberg wrote:
>> I mean, seriously, git makes it so easy to have a separate tree that
>> >  it almost doesn't make sense not to have one. You're constantly
>> >  working in separate trees yourself because every one of your
>> >  branches is separate. Keeping in sync with the kernel release cycles
>> >  (which I don't think makes any sense for you) should be easy enough
>> >  too by merely releasing in sync with the kernel tree...
> We'd be the only subsystem doing that!

GStreamer (V4L), RTSAdmin (LIO target), sg3_utils, trousers all are out 
of tree, and nobody of their authors is even thinking of doing all this 
brouhaha to get merged into Linus's tree.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/06/2011 07:05 PM, Pekka Enberg wrote:
>> I mean, seriously, git makes it so easy to have a separate tree that
>> >  it almost doesn't make sense not to have one. You're constantly
>> >  working in separate trees yourself because every one of your
>> >  branches is separate. Keeping in sync with the kernel release cycles
>> >  (which I don't think makes any sense for you) should be easy enough
>> >  too by merely releasing in sync with the kernel tree...
> We'd be the only subsystem doing that!

GStreamer (V4L), RTSAdmin (LIO target), sg3_utils, trousers all are out 
of tree, and nobody of their authors is even thinking of doing all this 
brouhaha to get merged into Linus's tree.

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/06/2011 06:28 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 7:15 PM, Alexander Graf<agraf@suse.de>  wrote:
>>> The difference here is that although I feel Alex's script is a
>>> pointless project, I'm in no way opposed to merging it in the tree if
>>> people use it and it solves their problem. Some people seem to be
>>> violently opposed to merging the KVM tool and I'm having difficult
>>> time understanding why that is.
>>
>> It's a matter of size and scope. Write a shell script that clones, builds and
>> executes KVM Tool and throw it in testing/tools/ and I'll happily ack it!
>
> That's pretty much what git submodule would do, isn't it?

Absolutely not.  It would always fetch HEAD from the KVM tool repo.  A 
submodule ties each supermodule commit to a particular submodule commit.

> I really don't see the point in doing that. We want to be part of
> regular kernel history and release cycle.

But I'm pretty certain that, when testing 3.2 with KVM tool in a couple 
of years, I want all the shining new features you added in this time; I 
don't want the old end-2011 code.  Same if I'm bisecting kernels, I 
don't want to build KVM tool once per bisection cycle, do I?

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Paolo Bonzini]

On 11/06/2011 06:28 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 7:15 PM, Alexander Graf<agraf@suse.de>  wrote:
>>> The difference here is that although I feel Alex's script is a
>>> pointless project, I'm in no way opposed to merging it in the tree if
>>> people use it and it solves their problem. Some people seem to be
>>> violently opposed to merging the KVM tool and I'm having difficult
>>> time understanding why that is.
>>
>> It's a matter of size and scope. Write a shell script that clones, builds and
>> executes KVM Tool and throw it in testing/tools/ and I'll happily ack it!
>
> That's pretty much what git submodule would do, isn't it?

Absolutely not.  It would always fetch HEAD from the KVM tool repo.  A 
submodule ties each supermodule commit to a particular submodule commit.

> I really don't see the point in doing that. We want to be part of
> regular kernel history and release cycle.

But I'm pretty certain that, when testing 3.2 with KVM tool in a couple 
of years, I want all the shining new features you added in this time; I 
don't want the old end-2011 code.  Same if I'm bisecting kernels, I 
don't want to build KVM tool once per bisection cycle, do I?

Paolo

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 7:08 PM, Anthony Liguori <anthony@codemonkey.ws> wrote:
> I'm quite happy with KVM tool and hope they continue working on it.  My only
> real wish is that they wouldn't copy QEMU so much and would try bolder
> things that are fundamentally different from QEMU.

Hey, right now our only source of crazy ideas is Ingo and I think he's
actually a pretty conservative guy when it comes to technology. Avi
has expressed some crazy ideas in the past but they require switching
away from C and that's not something we're interested in doing. ;-)

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 7:30 PM, Alexander Graf <agraf@suse.de> wrote:
>> That's pretty much what git submodule would do, isn't it?
>>
>> I really don't see the point in doing that. We want to be part of
>> regular kernel history and release cycle. We want people to be able to
>> see what's going on in our tree to keep us honest and we want to make
>> the barrier of entry as low as possible.
>>
>> It's not just about code, it's as much about culture and development process.
>
> So you're saying that projects that are not living in the kernel tree aren't worthwhile?

Yeah, that's exactly what I'm saying...

> Or are you only trying to bump your oloh stats?

That too!

On Sun, Nov 6, 2011 at 7:30 PM, Alexander Graf <agraf@suse.de> wrote:
> I mean, seriously, git makes it so easy to have a separate tree that
> it almost doesn't make sense not to have one. You're constantly
> working in separate trees yourself because every one of your
> branches is separate. Keeping in sync with the kernel release cycles
> (which I don't think makes any sense for you) should be easy enough
> too by merely releasing in sync with the kernel tree...

We'd be the only subsystem doing that! Why on earth do you think we
want to be the first ones to do that? We don't want to be different,
we want to make the barrier of entry low.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 7:30 PM, Alexander Graf <agraf@suse.de> wrote:
>> That's pretty much what git submodule would do, isn't it?
>>
>> I really don't see the point in doing that. We want to be part of
>> regular kernel history and release cycle. We want people to be able to
>> see what's going on in our tree to keep us honest and we want to make
>> the barrier of entry as low as possible.
>>
>> It's not just about code, it's as much about culture and development process.
>
> So you're saying that projects that are not living in the kernel tree aren't worthwhile?

Yeah, that's exactly what I'm saying...

> Or are you only trying to bump your oloh stats?

That too!

On Sun, Nov 6, 2011 at 7:30 PM, Alexander Graf <agraf@suse.de> wrote:
> I mean, seriously, git makes it so easy to have a separate tree that
> it almost doesn't make sense not to have one. You're constantly
> working in separate trees yourself because every one of your
> branches is separate. Keeping in sync with the kernel release cycles
> (which I don't think makes any sense for you) should be easy enough
> too by merely releasing in sync with the kernel tree...

We'd be the only subsystem doing that! Why on earth do you think we
want to be the first ones to do that? We don't want to be different,
we want to make the barrier of entry low.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, 6 Nov 2011, Jan Kiszka wrote:
> Doesn't help here (with a disk image).
>
> Also, both dependencies make no sense to me as we boot from disk, not
> from net, and the console is on ttyS0.

It's only VIRTIO_NET and the guest is not actually stuck, it just takes a 
while to boot:

[    1.866614] Installing 9P2000 support
[    1.868991] Registering the dns_resolver key type
[    1.878084] registered taskstats version 1
[   13.927367] Root-NFS: no NFS server address
[   13.929500] VFS: Unable to mount root fs via NFS, trying floppy.
[   13.939177] VFS: Mounted root (9p filesystem) on device 0:12.
[   13.941522] devtmpfs: mounted
[   13.943317] Freeing unused kernel memory: 684k freed
Mounting...
Starting '/bin/sh'...
sh-4.2#

I'm CC'ing Sasha and Asias.

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, 6 Nov 2011, Jan Kiszka wrote:
> Doesn't help here (with a disk image).
>
> Also, both dependencies make no sense to me as we boot from disk, not
> from net, and the console is on ttyS0.

It's only VIRTIO_NET and the guest is not actually stuck, it just takes a 
while to boot:

[    1.866614] Installing 9P2000 support
[    1.868991] Registering the dns_resolver key type
[    1.878084] registered taskstats version 1
[   13.927367] Root-NFS: no NFS server address
[   13.929500] VFS: Unable to mount root fs via NFS, trying floppy.
[   13.939177] VFS: Mounted root (9p filesystem) on device 0:12.
[   13.941522] devtmpfs: mounted
[   13.943317] Freeing unused kernel memory: 684k freed
Mounting...
Starting '/bin/sh'...
sh-4.2#

I'm CC'ing Sasha and Asias.

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 06.11.2011, at 09:28, Pekka Enberg wrote:

> On Sun, Nov 6, 2011 at 7:15 PM, Alexander Graf <agraf@suse.de> wrote:
>>> The difference here is that although I feel Alex's script is a
>>> pointless project, I'm in no way opposed to merging it in the tree if
>>> people use it and it solves their problem. Some people seem to be
>>> violently opposed to merging the KVM tool and I'm having difficult
>>> time understanding why that is.
>> 
>> It's a matter of size and scope. Write a shell script that clones, builds and
>> executes KVM Tool and throw it in testing/tools/ and I'll happily ack it!
> 
> That's pretty much what git submodule would do, isn't it?
> 
> I really don't see the point in doing that. We want to be part of
> regular kernel history and release cycle. We want people to be able to
> see what's going on in our tree to keep us honest and we want to make
> the barrier of entry as low as possible.
> 
> It's not just about code, it's as much about culture and development process.

So you're saying that projects that are not living in the kernel tree aren't worthwhile? Or are you only trying to bump your oloh stats?

I mean, seriously, git makes it so easy to have a separate tree that it almost doesn't make sense not to have one. You're constantly working in separate trees yourself because every one of your branches is separate. Keeping in sync with the kernel release cycles (which I don't think makes any sense for you) should be easy enough too by merely releasing in sync with the kernel tree...


Alex

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 06.11.2011, at 09:28, Pekka Enberg wrote:

> On Sun, Nov 6, 2011 at 7:15 PM, Alexander Graf <agraf@suse.de> wrote:
>>> The difference here is that although I feel Alex's script is a
>>> pointless project, I'm in no way opposed to merging it in the tree if
>>> people use it and it solves their problem. Some people seem to be
>>> violently opposed to merging the KVM tool and I'm having difficult
>>> time understanding why that is.
>> 
>> It's a matter of size and scope. Write a shell script that clones, builds and
>> executes KVM Tool and throw it in testing/tools/ and I'll happily ack it!
> 
> That's pretty much what git submodule would do, isn't it?
> 
> I really don't see the point in doing that. We want to be part of
> regular kernel history and release cycle. We want people to be able to
> see what's going on in our tree to keep us honest and we want to make
> the barrier of entry as low as possible.
> 
> It's not just about code, it's as much about culture and development process.

So you're saying that projects that are not living in the kernel tree aren't worthwhile? Or are you only trying to bump your oloh stats?

I mean, seriously, git makes it so easy to have a separate tree that it almost doesn't make sense not to have one. You're constantly working in separate trees yourself because every one of your branches is separate. Keeping in sync with the kernel release cycles (which I don't think makes any sense for you) should be easy enough too by merely releasing in sync with the kernel tree...


Alex

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 7:15 PM, Alexander Graf <agraf@suse.de> wrote:
>> The difference here is that although I feel Alex's script is a
>> pointless project, I'm in no way opposed to merging it in the tree if
>> people use it and it solves their problem. Some people seem to be
>> violently opposed to merging the KVM tool and I'm having difficult
>> time understanding why that is.
>
> It's a matter of size and scope. Write a shell script that clones, builds and
> executes KVM Tool and throw it in testing/tools/ and I'll happily ack it!

That's pretty much what git submodule would do, isn't it?

I really don't see the point in doing that. We want to be part of
regular kernel history and release cycle. We want people to be able to
see what's going on in our tree to keep us honest and we want to make
the barrier of entry as low as possible.

It's not just about code, it's as much about culture and development process.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 7:15 PM, Alexander Graf <agraf@suse.de> wrote:
>> The difference here is that although I feel Alex's script is a
>> pointless project, I'm in no way opposed to merging it in the tree if
>> people use it and it solves their problem. Some people seem to be
>> violently opposed to merging the KVM tool and I'm having difficult
>> time understanding why that is.
>
> It's a matter of size and scope. Write a shell script that clones, builds and
> executes KVM Tool and throw it in testing/tools/ and I'll happily ack it!

That's pretty much what git submodule would do, isn't it?

I really don't see the point in doing that. We want to be part of
regular kernel history and release cycle. We want people to be able to
see what's going on in our tree to keep us honest and we want to make
the barrier of entry as low as possible.

It's not just about code, it's as much about culture and development process.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

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On 2011-11-06 18:11, Pekka Enberg wrote:
> On Sun, 6 Nov 2011, Jan Kiszka wrote:
>>> Can you please share your kernel .config with me and I'll take a look
>>> at it. We now have a "make kvmconfig" makefile target for enabling all
>>> the necessary config options for guest kernels. I don't think any of
>>> us developers are using SUSE so it can surely be a KVM tool bug as
>>> well.
>>
>> Attached.
> 
> It hang here as well. I ran
> 
>   make kvmconfig
> 
> on your .config and it works. It's basically these two:
> 
> @@ -1478,7 +1478,7 @@
>  CONFIG_NETPOLL=y
>  # CONFIG_NETPOLL_TRAP is not set
>  CONFIG_NET_POLL_CONTROLLER=y
> -CONFIG_VIRTIO_NET=m
> +CONFIG_VIRTIO_NET=y
>  # CONFIG_VMXNET3 is not set
>  # CONFIG_ISDN is not set
>  # CONFIG_PHONE is not set
> @@ -1690,7 +1690,7 @@
>  # CONFIG_SERIAL_PCH_UART is not set
>  # CONFIG_SERIAL_XILINX_PS_UART is not set
>  CONFIG_HVC_DRIVER=y
> -CONFIG_VIRTIO_CONSOLE=m
> +CONFIG_VIRTIO_CONSOLE=y
>  CONFIG_IPMI_HANDLER=m
>  # CONFIG_IPMI_PANIC_EVENT is not set
>  CONFIG_IPMI_DEVICE_INTERFACE=m
> 
>             Pekka

Doesn't help here (with a disk image).

Also, both dependencies make no sense to me as we boot from disk, not
from net, and the console is on ttyS0.

Jan


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Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

[-- Attachment #1: Type: text/plain, Size: 1272 bytes --]

On 2011-11-06 18:11, Pekka Enberg wrote:
> On Sun, 6 Nov 2011, Jan Kiszka wrote:
>>> Can you please share your kernel .config with me and I'll take a look
>>> at it. We now have a "make kvmconfig" makefile target for enabling all
>>> the necessary config options for guest kernels. I don't think any of
>>> us developers are using SUSE so it can surely be a KVM tool bug as
>>> well.
>>
>> Attached.
> 
> It hang here as well. I ran
> 
>   make kvmconfig
> 
> on your .config and it works. It's basically these two:
> 
> @@ -1478,7 +1478,7 @@
>  CONFIG_NETPOLL=y
>  # CONFIG_NETPOLL_TRAP is not set
>  CONFIG_NET_POLL_CONTROLLER=y
> -CONFIG_VIRTIO_NET=m
> +CONFIG_VIRTIO_NET=y
>  # CONFIG_VMXNET3 is not set
>  # CONFIG_ISDN is not set
>  # CONFIG_PHONE is not set
> @@ -1690,7 +1690,7 @@
>  # CONFIG_SERIAL_PCH_UART is not set
>  # CONFIG_SERIAL_XILINX_PS_UART is not set
>  CONFIG_HVC_DRIVER=y
> -CONFIG_VIRTIO_CONSOLE=m
> +CONFIG_VIRTIO_CONSOLE=y
>  CONFIG_IPMI_HANDLER=m
>  # CONFIG_IPMI_PANIC_EVENT is not set
>  CONFIG_IPMI_DEVICE_INTERFACE=m
> 
>             Pekka

Doesn't help here (with a disk image).

Also, both dependencies make no sense to me as we boot from disk, not
from net, and the console is on ttyS0.

Jan


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Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 06.11.2011, at 05:06, Pekka Enberg wrote:

> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
>> You say that kvm-tool's scope is broader than Alex's script, therefore
>> the latter is pointless.
> 
> I'm saying that Alex's script is pointless because it's not attempting
> to fix the real issues. For example, we're trying to make make it as
> easy as possible to setup a guest and to be able to access guest data
> from the host. Alex's script is essentially just a simplified QEMU
> "front end" for kernel developers.
> 
> That's why I feel it's a pointless thing to do.

It's a script tailored to what Linus told me he wanted to see. I merely wanted to prove the point that what he wanted can be achieved without thousands and thousands of lines of code by reusing what is already there. IMHO less code is usually a good thing.

In fact, why don't you just provide a script in tools/testing/ that fetches KVM Tool from a git tree somewhere else and compiles it? It could easily live outside the kernel tree - you can even grab our awesome "fetch all Linux headers" script from QEMU so you can keep in sync with KVM header files.

At that point, both front ends would live in separate trees, could evolve however they like and everyone's happy, because KVM Tools would still be easy to use for people who want it by executing said shell script.

> 
> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
>> You accept that qemu's scope is broader than kvm-tool (and is a
>> superset).  That is why many people think kvm-tool is pointless.
> 
> Sure. I think it's mostly people that are interested in non-Linux
> virtualization that think the KVM tool is a pointless project.
> However, some people (including myself) think the KVM tool is a more
> usable and hackable tool than QEMU for Linux virtualization.

Sure. That's taste. If I think that tcsh is a better shell than bash do I pull it into the kernel tree just so "it lies there"? It definitely does use kernel interfaces too, so I can make up just as many reasons as you to pull it in.

> The difference here is that although I feel Alex's script is a
> pointless project, I'm in no way opposed to merging it in the tree if
> people use it and it solves their problem. Some people seem to be
> violently opposed to merging the KVM tool and I'm having difficult
> time understanding why that is.

It's a matter of size and scope. Write a shell script that clones, builds and executes KVM Tool and throw it in testing/tools/ and I'll happily ack it!


Alex

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On 06.11.2011, at 05:06, Pekka Enberg wrote:

> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
>> You say that kvm-tool's scope is broader than Alex's script, therefore
>> the latter is pointless.
> 
> I'm saying that Alex's script is pointless because it's not attempting
> to fix the real issues. For example, we're trying to make make it as
> easy as possible to setup a guest and to be able to access guest data
> from the host. Alex's script is essentially just a simplified QEMU
> "front end" for kernel developers.
> 
> That's why I feel it's a pointless thing to do.

It's a script tailored to what Linus told me he wanted to see. I merely wanted to prove the point that what he wanted can be achieved without thousands and thousands of lines of code by reusing what is already there. IMHO less code is usually a good thing.

In fact, why don't you just provide a script in tools/testing/ that fetches KVM Tool from a git tree somewhere else and compiles it? It could easily live outside the kernel tree - you can even grab our awesome "fetch all Linux headers" script from QEMU so you can keep in sync with KVM header files.

At that point, both front ends would live in separate trees, could evolve however they like and everyone's happy, because KVM Tools would still be easy to use for people who want it by executing said shell script.

> 
> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
>> You accept that qemu's scope is broader than kvm-tool (and is a
>> superset).  That is why many people think kvm-tool is pointless.
> 
> Sure. I think it's mostly people that are interested in non-Linux
> virtualization that think the KVM tool is a pointless project.
> However, some people (including myself) think the KVM tool is a more
> usable and hackable tool than QEMU for Linux virtualization.

Sure. That's taste. If I think that tcsh is a better shell than bash do I pull it into the kernel tree just so "it lies there"? It definitely does use kernel interfaces too, so I can make up just as many reasons as you to pull it in.

> The difference here is that although I feel Alex's script is a
> pointless project, I'm in no way opposed to merging it in the tree if
> people use it and it solves their problem. Some people seem to be
> violently opposed to merging the KVM tool and I'm having difficult
> time understanding why that is.

It's a matter of size and scope. Write a shell script that clones, builds and executes KVM Tool and throw it in testing/tools/ and I'll happily ack it!


Alex

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, 6 Nov 2011, Jan Kiszka wrote:
>> Can you please share your kernel .config with me and I'll take a look
>> at it. We now have a "make kvmconfig" makefile target for enabling all
>> the necessary config options for guest kernels. I don't think any of
>> us developers are using SUSE so it can surely be a KVM tool bug as
>> well.
>
> Attached.

It hang here as well. I ran

   make kvmconfig

on your .config and it works. It's basically these two:

@@ -1478,7 +1478,7 @@
  CONFIG_NETPOLL=y
  # CONFIG_NETPOLL_TRAP is not set
  CONFIG_NET_POLL_CONTROLLER=y
-CONFIG_VIRTIO_NET=m
+CONFIG_VIRTIO_NET=y
  # CONFIG_VMXNET3 is not set
  # CONFIG_ISDN is not set
  # CONFIG_PHONE is not set
@@ -1690,7 +1690,7 @@
  # CONFIG_SERIAL_PCH_UART is not set
  # CONFIG_SERIAL_XILINX_PS_UART is not set
  CONFIG_HVC_DRIVER=y
-CONFIG_VIRTIO_CONSOLE=m
+CONFIG_VIRTIO_CONSOLE=y
  CONFIG_IPMI_HANDLER=m
  # CONFIG_IPMI_PANIC_EVENT is not set
  CONFIG_IPMI_DEVICE_INTERFACE=m

 			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, 6 Nov 2011, Jan Kiszka wrote:
>> Can you please share your kernel .config with me and I'll take a look
>> at it. We now have a "make kvmconfig" makefile target for enabling all
>> the necessary config options for guest kernels. I don't think any of
>> us developers are using SUSE so it can surely be a KVM tool bug as
>> well.
>
> Attached.

It hang here as well. I ran

   make kvmconfig

on your .config and it works. It's basically these two:

@@ -1478,7 +1478,7 @@
  CONFIG_NETPOLL=y
  # CONFIG_NETPOLL_TRAP is not set
  CONFIG_NET_POLL_CONTROLLER=y
-CONFIG_VIRTIO_NET=m
+CONFIG_VIRTIO_NET=y
  # CONFIG_VMXNET3 is not set
  # CONFIG_ISDN is not set
  # CONFIG_PHONE is not set
@@ -1690,7 +1690,7 @@
  # CONFIG_SERIAL_PCH_UART is not set
  # CONFIG_SERIAL_XILINX_PS_UART is not set
  CONFIG_HVC_DRIVER=y
-CONFIG_VIRTIO_CONSOLE=m
+CONFIG_VIRTIO_CONSOLE=y
  CONFIG_IPMI_HANDLER=m
  # CONFIG_IPMI_PANIC_EVENT is not set
  CONFIG_IPMI_DEVICE_INTERFACE=m

 			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Anthony Liguori]

On 11/06/2011 07:06 AM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity<avi@redhat.com>  wrote:
>> You say that kvm-tool's scope is broader than Alex's script, therefore
>> the latter is pointless.
>
> I'm saying that Alex's script is pointless because it's not attempting
> to fix the real issues. For example, we're trying to make make it as
> easy as possible to setup a guest and to be able to access guest data
> from the host. Alex's script is essentially just a simplified QEMU
> "front end" for kernel developers.
>
> That's why I feel it's a pointless thing to do.
>
> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity<avi@redhat.com>  wrote:
>> You accept that qemu's scope is broader than kvm-tool (and is a
>> superset).  That is why many people think kvm-tool is pointless.
>
> Sure. I think it's mostly people that are interested in non-Linux
> virtualization that think the KVM tool is a pointless project.
> However, some people (including myself) think the KVM tool is a more
> usable and hackable tool than QEMU for Linux virtualization.

There are literally dozens of mini operating systems that exist for exactly the 
same reason that you describe above.  They are smaller and easier to hack on 
than something like Linux.

Regards,

Anthony Liguori

>
> The difference here is that although I feel Alex's script is a
> pointless project, I'm in no way opposed to merging it in the tree if
> people use it and it solves their problem. Some people seem to be
> violently opposed to merging the KVM tool and I'm having difficult
> time understanding why that is.
>
>                          Pekka
>

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

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On 06.11.2011, at 05:11, Pekka Enberg wrote:

> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
>> Alex's script, though, is just a few dozen lines.  kvm-tool is a 20K
>> patch - in fact 2X as large as kvm when it was first merged.  And it's
>> main feature seems to be that "it is not qemu".
> 
> I think I've mentioned many times that I find the QEMU source terribly
> difficult to read and hack on. So if you mean "not qemu" from that
> point of view, sure, I think it's a very important point. The command
> line interface is also "not qemu" for a very good reason too.

That's a matter of taste. In fact, I like the QEMU source code for most parts and there was a whole talk around it on LinuxCon where people agreed that it was really easy to hack away with to prototype new hardware:

  https://events.linuxfoundation.org/events/linuxcon-europe/waskiewicz

As for all matters concerning taste, I don't think we would ever get to a common ground here :).


Alex


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Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Anthony Liguori]

On 11/06/2011 10:50 AM, Avi Kivity wrote:
> On 11/06/2011 06:35 PM, Pekka Enberg wrote:
>>>> The difference here is that although I feel Alex's script is a
>>>> pointless project, I'm in no way opposed to merging it in the tree if
>>>> people use it and it solves their problem. Some people seem to be
>>>> violently opposed to merging the KVM tool and I'm having difficult
>>>> time understanding why that is.
>>>
>>> One of the reasons is that if it is merge, anyone with a #include
>>> <linux/foo.h>  will line up for the next merge window, wanting in.  The
>>> other is that anything in the Linux source tree might gain an unfair
>>> advantage over out-of-tree projects (at least that's how I read Jan's
>>> comment).
>>
>> Well, having gone through the process of getting something included so
>> far, I'm not at all worried that there's going to be a huge queue of
>> "#include<linux/foo.h>" projects if we get in...
>>
>> What kind of unfair advantage are you referring to? I've specifically
>> said that the only way for KVM tool to become a reference
>> implementation would be that the KVM maintainers take the tool through
>> their tree. As that's not going to happen, I don't see what the
>> problem would be.
>
> I'm not personally worried about it either (though in fact a *minimal*
> reference implementation might not be a bad idea).  There's the risk of
> getting informed in-depth press reviews ("Linux KVM Takes A Step Back
>  From Running Windows Guests"), or of unfairly drawing developers away
> from competing projects.

I don't think that's really a concern.  Competition is a good thing.  QEMU is a 
large code base that a lot of people rely upon.  It's hard to take big risks in 
a project like QEMU because the consequences are too high.

OTOH, a project like KVM tool can take a lot of risks.  They've attempted a very 
different command line syntax and they've put a lot of work into making 
virtio-9p a main part of the interface.

If it turns out that these things end up working out well for them, then it 
becomes something we can copy in QEMU.  If not, then we didn't go through the 
train wreck of totally changing CLI syntax only to find it was the wrong syntax.

I'm quite happy with KVM tool and hope they continue working on it.  My only 
real wish is that they wouldn't copy QEMU so much and would try bolder things 
that are fundamentally different from QEMU.

Regards,

Anthony Liguori

>

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 06:35 PM, Pekka Enberg wrote:
> >> The difference here is that although I feel Alex's script is a
> >> pointless project, I'm in no way opposed to merging it in the tree if
> >> people use it and it solves their problem. Some people seem to be
> >> violently opposed to merging the KVM tool and I'm having difficult
> >> time understanding why that is.
> >
> > One of the reasons is that if it is merge, anyone with a #include
> > <linux/foo.h> will line up for the next merge window, wanting in.  The
> > other is that anything in the Linux source tree might gain an unfair
> > advantage over out-of-tree projects (at least that's how I read Jan's
> > comment).
>
> Well, having gone through the process of getting something included so
> far, I'm not at all worried that there's going to be a huge queue of
> "#include <linux/foo.h>" projects if we get in...
>
> What kind of unfair advantage are you referring to? I've specifically
> said that the only way for KVM tool to become a reference
> implementation would be that the KVM maintainers take the tool through
> their tree. As that's not going to happen, I don't see what the
> problem would be.

I'm not personally worried about it either (though in fact a *minimal*
reference implementation might not be a bad idea).  There's the risk of
getting informed in-depth press reviews ("Linux KVM Takes A Step Back
>From Running Windows Guests"), or of unfairly drawing developers away
from competing projects.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

[-- Attachment #1.1: Type: text/plain, Size: 1517 bytes --]

On 2011-11-06 17:30, Pekka Enberg wrote:
> Hi Jan,
> 
> On Sun, Nov 6, 2011 at 6:19 PM, Jan Kiszka <jan.kiszka@web.de> wrote:
>> "Usable" - I've tried kvm-tool several times and still (today) fail to
>> get a standard SUSE image (with a kernel I have to compile and provide
>> separately...) up and running *). Likely a user mistake, but none that
>> is very obvious. At least to me.
>>
>> In contrast, you can throw arbitrary Linux distros in various forms at
>> QEMU, and it will catch and run them. For me, already this is more usable.
>>
>> *) kvm run -m 1000 -d OpenSuse11-4_64.img arch/x86/boot/bzImage \
>>        -p root=/dev/vda2
>> ...
>> [    1.772791] mousedev: PS/2 mouse device common for all mice
>> [    1.774603] cpuidle: using governor ladder
>> [    1.775490] cpuidle: using governor menu
>> [    1.776865] input: AT Raw Set 2 keyboard as
>> /devices/platform/i8042/serio0/input/input0
>> [    1.778609] TCP cubic registered
>> [    1.779456] Installing 9P2000 support
>> [    1.782390] Registering the dns_resolver key type
>> [    1.794323] registered taskstats version 1
>>
>> ...and here the boot just stops, guest apparently waits for something
> 
> Can you please share your kernel .config with me and I'll take a look
> at it. We now have a "make kvmconfig" makefile target for enabling all
> the necessary config options for guest kernels. I don't think any of
> us developers are using SUSE so it can surely be a KVM tool bug as
> well.

Attached.

Jan

[-- Attachment #1.2: .config.bz2 --]
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Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

[-- Attachment #1.1: Type: text/plain, Size: 1517 bytes --]

On 2011-11-06 17:30, Pekka Enberg wrote:
> Hi Jan,
> 
> On Sun, Nov 6, 2011 at 6:19 PM, Jan Kiszka <jan.kiszka@web.de> wrote:
>> "Usable" - I've tried kvm-tool several times and still (today) fail to
>> get a standard SUSE image (with a kernel I have to compile and provide
>> separately...) up and running *). Likely a user mistake, but none that
>> is very obvious. At least to me.
>>
>> In contrast, you can throw arbitrary Linux distros in various forms at
>> QEMU, and it will catch and run them. For me, already this is more usable.
>>
>> *) kvm run -m 1000 -d OpenSuse11-4_64.img arch/x86/boot/bzImage \
>>        -p root=/dev/vda2
>> ...
>> [    1.772791] mousedev: PS/2 mouse device common for all mice
>> [    1.774603] cpuidle: using governor ladder
>> [    1.775490] cpuidle: using governor menu
>> [    1.776865] input: AT Raw Set 2 keyboard as
>> /devices/platform/i8042/serio0/input/input0
>> [    1.778609] TCP cubic registered
>> [    1.779456] Installing 9P2000 support
>> [    1.782390] Registering the dns_resolver key type
>> [    1.794323] registered taskstats version 1
>>
>> ...and here the boot just stops, guest apparently waits for something
> 
> Can you please share your kernel .config with me and I'll take a look
> at it. We now have a "make kvmconfig" makefile target for enabling all
> the necessary config options for guest kernels. I don't think any of
> us developers are using SUSE so it can surely be a KVM tool bug as
> well.

Attached.

Jan

[-- Attachment #1.2: .config.bz2 --]
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Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 6:19 PM, Jan Kiszka <jan.kiszka@web.de> wrote:
> In contrast, you can throw arbitrary Linux distros in various forms at
> QEMU, and it will catch and run them. For me, already this is more usable.

Yes, I completely agree that this is an unfortunate limitation in the
KVM tool. We definitely need to support booting to images which have
virtio drivers enabled.

                         Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 6:19 PM, Jan Kiszka <jan.kiszka@web.de> wrote:
> In contrast, you can throw arbitrary Linux distros in various forms at
> QEMU, and it will catch and run them. For me, already this is more usable.

Yes, I completely agree that this is an unfortunate limitation in the
KVM tool. We definitely need to support booting to images which have
virtio drivers enabled.

                         Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Avi,

On Sun, Nov 6, 2011 at 5:56 PM, Avi Kivity <avi@redhat.com> wrote:
> On 11/06/2011 03:06 PM, Pekka Enberg wrote:
>> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
>> > You say that kvm-tool's scope is broader than Alex's script, therefore
>> > the latter is pointless.
>>
>> I'm saying that Alex's script is pointless because it's not attempting
>> to fix the real issues. For example, we're trying to make make it as
>> easy as possible to setup a guest and to be able to access guest data
>> from the host.
>
> Have you tried virt-install/virt-manager?

No, I don't use virtio-manager. I know a lot of people do which is why
someone is working on KVM tool libvirt integration.

>> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
>> > You accept that qemu's scope is broader than kvm-tool (and is a
>> > superset).  That is why many people think kvm-tool is pointless.
>>
>> Sure. I think it's mostly people that are interested in non-Linux
>> virtualization that think the KVM tool is a pointless project.
>> However, some people (including myself) think the KVM tool is a more
>> usable and hackable tool than QEMU for Linux virtualization.
>
> More hackable, certainly, as any 20kloc project will be compared to a
> 700+kloc project with a long history.  More usable, I really doubt
> this.  You take it for granted that people want to run their /boot
> kernels in a guest, but in fact only kernel developers (and testers)
> want this.  The majority want the real guest kernel.

Our inability to boot ISO images, for example, is a usability
limitation, sure. I'm hoping to fix that at some point.

>> The difference here is that although I feel Alex's script is a
>> pointless project, I'm in no way opposed to merging it in the tree if
>> people use it and it solves their problem. Some people seem to be
>> violently opposed to merging the KVM tool and I'm having difficult
>> time understanding why that is.
>
> One of the reasons is that if it is merge, anyone with a #include
> <linux/foo.h> will line up for the next merge window, wanting in.  The
> other is that anything in the Linux source tree might gain an unfair
> advantage over out-of-tree projects (at least that's how I read Jan's
> comment).

Well, having gone through the process of getting something included so
far, I'm not at all worried that there's going to be a huge queue of
"#include <linux/foo.h>" projects if we get in...

What kind of unfair advantage are you referring to? I've specifically
said that the only way for KVM tool to become a reference
implementation would be that the KVM maintainers take the tool through
their tree. As that's not going to happen, I don't see what the
problem would be.

                                 Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Avi,

On Sun, Nov 6, 2011 at 5:56 PM, Avi Kivity <avi@redhat.com> wrote:
> On 11/06/2011 03:06 PM, Pekka Enberg wrote:
>> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
>> > You say that kvm-tool's scope is broader than Alex's script, therefore
>> > the latter is pointless.
>>
>> I'm saying that Alex's script is pointless because it's not attempting
>> to fix the real issues. For example, we're trying to make make it as
>> easy as possible to setup a guest and to be able to access guest data
>> from the host.
>
> Have you tried virt-install/virt-manager?

No, I don't use virtio-manager. I know a lot of people do which is why
someone is working on KVM tool libvirt integration.

>> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
>> > You accept that qemu's scope is broader than kvm-tool (and is a
>> > superset).  That is why many people think kvm-tool is pointless.
>>
>> Sure. I think it's mostly people that are interested in non-Linux
>> virtualization that think the KVM tool is a pointless project.
>> However, some people (including myself) think the KVM tool is a more
>> usable and hackable tool than QEMU for Linux virtualization.
>
> More hackable, certainly, as any 20kloc project will be compared to a
> 700+kloc project with a long history.  More usable, I really doubt
> this.  You take it for granted that people want to run their /boot
> kernels in a guest, but in fact only kernel developers (and testers)
> want this.  The majority want the real guest kernel.

Our inability to boot ISO images, for example, is a usability
limitation, sure. I'm hoping to fix that at some point.

>> The difference here is that although I feel Alex's script is a
>> pointless project, I'm in no way opposed to merging it in the tree if
>> people use it and it solves their problem. Some people seem to be
>> violently opposed to merging the KVM tool and I'm having difficult
>> time understanding why that is.
>
> One of the reasons is that if it is merge, anyone with a #include
> <linux/foo.h> will line up for the next merge window, wanting in.  The
> other is that anything in the Linux source tree might gain an unfair
> advantage over out-of-tree projects (at least that's how I read Jan's
> comment).

Well, having gone through the process of getting something included so
far, I'm not at all worried that there's going to be a huge queue of
"#include <linux/foo.h>" projects if we get in...

What kind of unfair advantage are you referring to? I've specifically
said that the only way for KVM tool to become a reference
implementation would be that the KVM maintainers take the tool through
their tree. As that's not going to happen, I don't see what the
problem would be.

                                 Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Jan,

On Sun, Nov 6, 2011 at 6:19 PM, Jan Kiszka <jan.kiszka@web.de> wrote:
> "Usable" - I've tried kvm-tool several times and still (today) fail to
> get a standard SUSE image (with a kernel I have to compile and provide
> separately...) up and running *). Likely a user mistake, but none that
> is very obvious. At least to me.
>
> In contrast, you can throw arbitrary Linux distros in various forms at
> QEMU, and it will catch and run them. For me, already this is more usable.
>
> *) kvm run -m 1000 -d OpenSuse11-4_64.img arch/x86/boot/bzImage \
>        -p root=/dev/vda2
> ...
> [    1.772791] mousedev: PS/2 mouse device common for all mice
> [    1.774603] cpuidle: using governor ladder
> [    1.775490] cpuidle: using governor menu
> [    1.776865] input: AT Raw Set 2 keyboard as
> /devices/platform/i8042/serio0/input/input0
> [    1.778609] TCP cubic registered
> [    1.779456] Installing 9P2000 support
> [    1.782390] Registering the dns_resolver key type
> [    1.794323] registered taskstats version 1
>
> ...and here the boot just stops, guest apparently waits for something

Can you please share your kernel .config with me and I'll take a look
at it. We now have a "make kvmconfig" makefile target for enabling all
the necessary config options for guest kernels. I don't think any of
us developers are using SUSE so it can surely be a KVM tool bug as
well.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Jan,

On Sun, Nov 6, 2011 at 6:19 PM, Jan Kiszka <jan.kiszka@web.de> wrote:
> "Usable" - I've tried kvm-tool several times and still (today) fail to
> get a standard SUSE image (with a kernel I have to compile and provide
> separately...) up and running *). Likely a user mistake, but none that
> is very obvious. At least to me.
>
> In contrast, you can throw arbitrary Linux distros in various forms at
> QEMU, and it will catch and run them. For me, already this is more usable.
>
> *) kvm run -m 1000 -d OpenSuse11-4_64.img arch/x86/boot/bzImage \
>        -p root=/dev/vda2
> ...
> [    1.772791] mousedev: PS/2 mouse device common for all mice
> [    1.774603] cpuidle: using governor ladder
> [    1.775490] cpuidle: using governor menu
> [    1.776865] input: AT Raw Set 2 keyboard as
> /devices/platform/i8042/serio0/input/input0
> [    1.778609] TCP cubic registered
> [    1.779456] Installing 9P2000 support
> [    1.782390] Registering the dns_resolver key type
> [    1.794323] registered taskstats version 1
>
> ...and here the boot just stops, guest apparently waits for something

Can you please share your kernel .config with me and I'll take a look
at it. We now have a "make kvmconfig" makefile target for enabling all
the necessary config options for guest kernels. I don't think any of
us developers are using SUSE so it can surely be a KVM tool bug as
well.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Jan Kiszka]

[-- Attachment #1: Type: text/plain, Size: 1528 bytes --]

On 2011-11-06 14:06, Pekka Enberg wrote:
> Sure. I think it's mostly people that are interested in non-Linux
> virtualization that think the KVM tool is a pointless project.
> However, some people (including myself) think the KVM tool is a more
> usable and hackable tool than QEMU for Linux virtualization.

"Hackable" is relative. I'm surly not saying QEMU has nicer code than
kvm-tool, rather the contrary. But if it were that bad, we would not
have hundreds of contributors, just in the very recent history.

"Usable" - I've tried kvm-tool several times and still (today) fail to
get a standard SUSE image (with a kernel I have to compile and provide
separately...) up and running *). Likely a user mistake, but none that
is very obvious. At least to me.

In contrast, you can throw arbitrary Linux distros in various forms at
QEMU, and it will catch and run them. For me, already this is more usable.

Jan

*) kvm run -m 1000 -d OpenSuse11-4_64.img arch/x86/boot/bzImage \
	-p root=/dev/vda2
...
[    1.772791] mousedev: PS/2 mouse device common for all mice
[    1.774603] cpuidle: using governor ladder
[    1.775490] cpuidle: using governor menu
[    1.776865] input: AT Raw Set 2 keyboard as
/devices/platform/i8042/serio0/input/input0
[    1.778609] TCP cubic registered
[    1.779456] Installing 9P2000 support
[    1.782390] Registering the dns_resolver key type
[    1.794323] registered taskstats version 1

...and here the boot just stops, guest apparently waits for something


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 262 bytes --]

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 03:06 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> > You say that kvm-tool's scope is broader than Alex's script, therefore
> > the latter is pointless.
>
> I'm saying that Alex's script is pointless because it's not attempting
> to fix the real issues. For example, we're trying to make make it as
> easy as possible to setup a guest and to be able to access guest data
> from the host.

Have you tried virt-install/virt-manager?

> Alex's script is essentially just a simplified QEMU
> "front end" for kernel developers.

AFAIR it was based off a random Linus remark.

> That's why I feel it's a pointless thing to do.
>
> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> > You accept that qemu's scope is broader than kvm-tool (and is a
> > superset).  That is why many people think kvm-tool is pointless.
>
> Sure. I think it's mostly people that are interested in non-Linux
> virtualization that think the KVM tool is a pointless project.
> However, some people (including myself) think the KVM tool is a more
> usable and hackable tool than QEMU for Linux virtualization.

More hackable, certainly, as any 20kloc project will be compared to a
700+kloc project with a long history.  More usable, I really doubt
this.  You take it for granted that people want to run their /boot
kernels in a guest, but in fact only kernel developers (and testers)
want this.  The majority want the real guest kernel.

> The difference here is that although I feel Alex's script is a
> pointless project, I'm in no way opposed to merging it in the tree if
> people use it and it solves their problem. Some people seem to be
> violently opposed to merging the KVM tool and I'm having difficult
> time understanding why that is.

One of the reasons is that if it is merge, anyone with a #include
<linux/foo.h> will line up for the next merge window, wanting in.  The
other is that anything in the Linux source tree might gain an unfair
advantage over out-of-tree projects (at least that's how I read Jan's
comment).

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 03:06 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> > You say that kvm-tool's scope is broader than Alex's script, therefore
> > the latter is pointless.
>
> I'm saying that Alex's script is pointless because it's not attempting
> to fix the real issues. For example, we're trying to make make it as
> easy as possible to setup a guest and to be able to access guest data
> from the host.

Have you tried virt-install/virt-manager?

> Alex's script is essentially just a simplified QEMU
> "front end" for kernel developers.

AFAIR it was based off a random Linus remark.

> That's why I feel it's a pointless thing to do.
>
> On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> > You accept that qemu's scope is broader than kvm-tool (and is a
> > superset).  That is why many people think kvm-tool is pointless.
>
> Sure. I think it's mostly people that are interested in non-Linux
> virtualization that think the KVM tool is a pointless project.
> However, some people (including myself) think the KVM tool is a more
> usable and hackable tool than QEMU for Linux virtualization.

More hackable, certainly, as any 20kloc project will be compared to a
700+kloc project with a long history.  More usable, I really doubt
this.  You take it for granted that people want to run their /boot
kernels in a guest, but in fact only kernel developers (and testers)
want this.  The majority want the real guest kernel.

> The difference here is that although I feel Alex's script is a
> pointless project, I'm in no way opposed to merging it in the tree if
> people use it and it solves their problem. Some people seem to be
> violently opposed to merging the KVM tool and I'm having difficult
> time understanding why that is.

One of the reasons is that if it is merge, anyone with a #include
<linux/foo.h> will line up for the next merge window, wanting in.  The
other is that anything in the Linux source tree might gain an unfair
advantage over out-of-tree projects (at least that's how I read Jan's
comment).

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> Alex's script, though, is just a few dozen lines.  kvm-tool is a 20K
> patch - in fact 2X as large as kvm when it was first merged.  And it's
> main feature seems to be that "it is not qemu".

I think I've mentioned many times that I find the QEMU source terribly
difficult to read and hack on. So if you mean "not qemu" from that
point of view, sure, I think it's a very important point. The command
line interface is also "not qemu" for a very good reason too.

As for virtio drivers and such, we're actually following QEMU's
example very closely. I guess we're going to diverge a bit for better
guest isolation but fundamentally I don't see why we'd want to be
totally different from QEMU on that level.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> Alex's script, though, is just a few dozen lines.  kvm-tool is a 20K
> patch - in fact 2X as large as kvm when it was first merged.  And it's
> main feature seems to be that "it is not qemu".

I think I've mentioned many times that I find the QEMU source terribly
difficult to read and hack on. So if you mean "not qemu" from that
point of view, sure, I think it's a very important point. The command
line interface is also "not qemu" for a very good reason too.

As for virtio drivers and such, we're actually following QEMU's
example very closely. I guess we're going to diverge a bit for better
guest isolation but fundamentally I don't see why we'd want to be
totally different from QEMU on that level.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> You say that kvm-tool's scope is broader than Alex's script, therefore
> the latter is pointless.

I'm saying that Alex's script is pointless because it's not attempting
to fix the real issues. For example, we're trying to make make it as
easy as possible to setup a guest and to be able to access guest data
from the host. Alex's script is essentially just a simplified QEMU
"front end" for kernel developers.

That's why I feel it's a pointless thing to do.

On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> You accept that qemu's scope is broader than kvm-tool (and is a
> superset).  That is why many people think kvm-tool is pointless.

Sure. I think it's mostly people that are interested in non-Linux
virtualization that think the KVM tool is a pointless project.
However, some people (including myself) think the KVM tool is a more
usable and hackable tool than QEMU for Linux virtualization.

The difference here is that although I feel Alex's script is a
pointless project, I'm in no way opposed to merging it in the tree if
people use it and it solves their problem. Some people seem to be
violently opposed to merging the KVM tool and I'm having difficult
time understanding why that is.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> You say that kvm-tool's scope is broader than Alex's script, therefore
> the latter is pointless.

I'm saying that Alex's script is pointless because it's not attempting
to fix the real issues. For example, we're trying to make make it as
easy as possible to setup a guest and to be able to access guest data
from the host. Alex's script is essentially just a simplified QEMU
"front end" for kernel developers.

That's why I feel it's a pointless thing to do.

On Sun, Nov 6, 2011 at 2:43 PM, Avi Kivity <avi@redhat.com> wrote:
> You accept that qemu's scope is broader than kvm-tool (and is a
> superset).  That is why many people think kvm-tool is pointless.

Sure. I think it's mostly people that are interested in non-Linux
virtualization that think the KVM tool is a pointless project.
However, some people (including myself) think the KVM tool is a more
usable and hackable tool than QEMU for Linux virtualization.

The difference here is that although I feel Alex's script is a
pointless project, I'm in no way opposed to merging it in the tree if
people use it and it solves their problem. Some people seem to be
violently opposed to merging the KVM tool and I'm having difficult
time understanding why that is.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 02:32 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 2:27 PM, Avi Kivity <avi@redhat.com> wrote:
> > But from your description, you're trying to solve just another narrow
> > problem:
> >
> > "The end game for me is to replace QEMU/VirtualBox for Linux on Linux
> > virtualization for my day to day purposes. "
> >
> > We rarely merge a subsystem to solve one person's problem (esp. when it
> > is defined as "replace another freely available project", even if you
> > dislike its command line syntax).
>
> I really don't understand your point. Other people are using the KVM
> tool for other purposes. For example, the (crazy) simulation guys are
> using the tool to launch even more guests on a single host and Ingo
> seems to be using the tool to test kernels.
>
> I'm not suggesting we should merge the tool because of my particular
> use case. I'm simply saying the problem I personally want to solve
> with the KVM tool is broader than what Alexander's script is doing.
> That's why I feel it's a pointless project.

We're going in circles, but I'll try again.

You say that kvm-tool's scope is broader than Alex's script, therefore
the latter is pointless.
You accept that qemu's scope is broader than kvm-tool (and is a
superset).  That is why many people think kvm-tool is pointless.

Alex's script, though, is just a few dozen lines.  kvm-tool is a 20K
patch - in fact 2X as large as kvm when it was first merged.  And it's
main feature seems to be that "it is not qemu".

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 02:32 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 2:27 PM, Avi Kivity <avi@redhat.com> wrote:
> > But from your description, you're trying to solve just another narrow
> > problem:
> >
> > "The end game for me is to replace QEMU/VirtualBox for Linux on Linux
> > virtualization for my day to day purposes. "
> >
> > We rarely merge a subsystem to solve one person's problem (esp. when it
> > is defined as "replace another freely available project", even if you
> > dislike its command line syntax).
>
> I really don't understand your point. Other people are using the KVM
> tool for other purposes. For example, the (crazy) simulation guys are
> using the tool to launch even more guests on a single host and Ingo
> seems to be using the tool to test kernels.
>
> I'm not suggesting we should merge the tool because of my particular
> use case. I'm simply saying the problem I personally want to solve
> with the KVM tool is broader than what Alexander's script is doing.
> That's why I feel it's a pointless project.

We're going in circles, but I'll try again.

You say that kvm-tool's scope is broader than Alex's script, therefore
the latter is pointless.
You accept that qemu's scope is broader than kvm-tool (and is a
superset).  That is why many people think kvm-tool is pointless.

Alex's script, though, is just a few dozen lines.  kvm-tool is a 20K
patch - in fact 2X as large as kvm when it was first merged.  And it's
main feature seems to be that "it is not qemu".

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 2:27 PM, Avi Kivity <avi@redhat.com> wrote:
> But from your description, you're trying to solve just another narrow
> problem:
>
> "The end game for me is to replace QEMU/VirtualBox for Linux on Linux
> virtualization for my day to day purposes. "
>
> We rarely merge a subsystem to solve one person's problem (esp. when it
> is defined as "replace another freely available project", even if you
> dislike its command line syntax).

I really don't understand your point. Other people are using the KVM
tool for other purposes. For example, the (crazy) simulation guys are
using the tool to launch even more guests on a single host and Ingo
seems to be using the tool to test kernels.

I'm not suggesting we should merge the tool because of my particular
use case. I'm simply saying the problem I personally want to solve
with the KVM tool is broader than what Alexander's script is doing.
That's why I feel it's a pointless project.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 2:27 PM, Avi Kivity <avi@redhat.com> wrote:
> But from your description, you're trying to solve just another narrow
> problem:
>
> "The end game for me is to replace QEMU/VirtualBox for Linux on Linux
> virtualization for my day to day purposes. "
>
> We rarely merge a subsystem to solve one person's problem (esp. when it
> is defined as "replace another freely available project", even if you
> dislike its command line syntax).

I really don't understand your point. Other people are using the KVM
tool for other purposes. For example, the (crazy) simulation guys are
using the tool to launch even more guests on a single host and Ingo
seems to be using the tool to test kernels.

I'm not suggesting we should merge the tool because of my particular
use case. I'm simply saying the problem I personally want to solve
with the KVM tool is broader than what Alexander's script is doing.
That's why I feel it's a pointless project.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 1:50 PM, Avi Kivity <avi@redhat.com> wrote:
> So far, kvm-tool capabilities are a subset of qemu's.  Does it add
> anything beyond a different command-line?

I think "different command line" is a big thing which is why we've
spent so much time on it. But if you mean other end user features, no,
we don't add anything new on the table right now. I think our
userspace networking implementation is better than QEMU's slirp but
that's purely technical thing.

I also don't think we should add new features for their own sake.
Linux virtualization isn't a terribly difficult thing to do thanks to
KVM and virtio drivers. I think most of the big ticket items will be
doing things like improving guest isolation and making guests more
accessible to the host.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 1:50 PM, Avi Kivity <avi@redhat.com> wrote:
> So far, kvm-tool capabilities are a subset of qemu's.  Does it add
> anything beyond a different command-line?

I think "different command line" is a big thing which is why we've
spent so much time on it. But if you mean other end user features, no,
we don't add anything new on the table right now. I think our
userspace networking implementation is better than QEMU's slirp but
that's purely technical thing.

I also don't think we should add new features for their own sake.
Linux virtualization isn't a terribly difficult thing to do thanks to
KVM and virtio drivers. I think most of the big ticket items will be
doing things like improving guest isolation and making guests more
accessible to the host.

                                Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 02:14 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 1:50 PM, Avi Kivity <avi@redhat.com> wrote:
> >> People seem to think the KVM tool is only about solving a specific
> >> problem to kernel developers. That's certainly never been my goal as I
> >> do lots of userspace programming as well. The end game for me is to
> >> replace QEMU/VirtualBox for Linux on Linux virtualization for my day to
> >> day purposes.
> >
> > Maybe it should be in tools/pekka then.  Usually subsystems that want to
> > be merged into Linux have broaded audiences though.
>
> I think you completely missed my point.
>
> I'm simply saying that KVM tool was never about solving a narrow
> problem Alexander's script is trying to solve. That's why I feel it's
> such a pointless exercise.

But from your description, you're trying to solve just another narrow
problem:

"The end game for me is to replace QEMU/VirtualBox for Linux on Linux
virtualization for my day to day purposes. "

We rarely merge a subsystem to solve one person's problem (esp. when it
is defined as "replace another freely available project", even if you
dislike its command line syntax).

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 02:14 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 1:50 PM, Avi Kivity <avi@redhat.com> wrote:
> >> People seem to think the KVM tool is only about solving a specific
> >> problem to kernel developers. That's certainly never been my goal as I
> >> do lots of userspace programming as well. The end game for me is to
> >> replace QEMU/VirtualBox for Linux on Linux virtualization for my day to
> >> day purposes.
> >
> > Maybe it should be in tools/pekka then.  Usually subsystems that want to
> > be merged into Linux have broaded audiences though.
>
> I think you completely missed my point.
>
> I'm simply saying that KVM tool was never about solving a narrow
> problem Alexander's script is trying to solve. That's why I feel it's
> such a pointless exercise.

But from your description, you're trying to solve just another narrow
problem:

"The end game for me is to replace QEMU/VirtualBox for Linux on Linux
virtualization for my day to day purposes. "

We rarely merge a subsystem to solve one person's problem (esp. when it
is defined as "replace another freely available project", even if you
dislike its command line syntax).

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 1:50 PM, Avi Kivity <avi@redhat.com> wrote:
>> People seem to think the KVM tool is only about solving a specific
>> problem to kernel developers. That's certainly never been my goal as I
>> do lots of userspace programming as well. The end game for me is to
>> replace QEMU/VirtualBox for Linux on Linux virtualization for my day to
>> day purposes.
>
> Maybe it should be in tools/pekka then.  Usually subsystems that want to
> be merged into Linux have broaded audiences though.

I think you completely missed my point.

I'm simply saying that KVM tool was never about solving a narrow
problem Alexander's script is trying to solve. That's why I feel it's
such a pointless exercise.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 1:50 PM, Avi Kivity <avi@redhat.com> wrote:
>> People seem to think the KVM tool is only about solving a specific
>> problem to kernel developers. That's certainly never been my goal as I
>> do lots of userspace programming as well. The end game for me is to
>> replace QEMU/VirtualBox for Linux on Linux virtualization for my day to
>> day purposes.
>
> Maybe it should be in tools/pekka then.  Usually subsystems that want to
> be merged into Linux have broaded audiences though.

I think you completely missed my point.

I'm simply saying that KVM tool was never about solving a narrow
problem Alexander's script is trying to solve. That's why I feel it's
such a pointless exercise.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 01:08 PM, Pekka Enberg wrote:
> On Sun, 2011-11-06 at 12:23 +0200, Avi Kivity wrote:
> > In most installations, qemu is driven by other programs, so any changes
> > to the command line would be invisible, except insofar as they break things.
> > 
> > For the occasional direct user of qemu, something like 'qemu-kvm -m 1G
> > /images/blah.img' is enough to boot an image.  This script doesn't help
> > in any way.
> > 
> > This script is for kernel developers who don't want to bother with
> > setting up a disk image (which, btw, many are still required to do - I'm
> > guessing most kernel developers who use qemu are cross-arch).  It has
> > limited scope and works mostly by hiding qemu features.  As such it
> > doesn't belong in qemu.
>
> I'm certainly not against merging the script if people are actually
> using it and it solves their problem.
>
> I personally find the whole exercise pointless because it's not
> attempting to solve any of the fundamental issues QEMU command line
> interface

There are no "fundamental qemu command line issues".  It's hairy, yes,
and verbose, but using "fundamental" to describe a choice between one
arcane set command line options and another is a bit of overstatement. 
Most users will use a GUI anyway.

>  has nor does it try to make Linux on Linux virtualization
> simpler and more integrated.

So far, kvm-tool capabilities are a subset of qemu's.  Does it add
anything beyond a different command-line?

> People seem to think the KVM tool is only about solving a specific
> problem to kernel developers. That's certainly never been my goal as I
> do lots of userspace programming as well. The end game for me is to
> replace QEMU/VirtualBox for Linux on Linux virtualization for my day to
> day purposes.

Maybe it should be in tools/pekka then.  Usually subsystems that want to
be merged into Linux have broaded audiences though.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 01:08 PM, Pekka Enberg wrote:
> On Sun, 2011-11-06 at 12:23 +0200, Avi Kivity wrote:
> > In most installations, qemu is driven by other programs, so any changes
> > to the command line would be invisible, except insofar as they break things.
> > 
> > For the occasional direct user of qemu, something like 'qemu-kvm -m 1G
> > /images/blah.img' is enough to boot an image.  This script doesn't help
> > in any way.
> > 
> > This script is for kernel developers who don't want to bother with
> > setting up a disk image (which, btw, many are still required to do - I'm
> > guessing most kernel developers who use qemu are cross-arch).  It has
> > limited scope and works mostly by hiding qemu features.  As such it
> > doesn't belong in qemu.
>
> I'm certainly not against merging the script if people are actually
> using it and it solves their problem.
>
> I personally find the whole exercise pointless because it's not
> attempting to solve any of the fundamental issues QEMU command line
> interface

There are no "fundamental qemu command line issues".  It's hairy, yes,
and verbose, but using "fundamental" to describe a choice between one
arcane set command line options and another is a bit of overstatement. 
Most users will use a GUI anyway.

>  has nor does it try to make Linux on Linux virtualization
> simpler and more integrated.

So far, kvm-tool capabilities are a subset of qemu's.  Does it add
anything beyond a different command-line?

> People seem to think the KVM tool is only about solving a specific
> problem to kernel developers. That's certainly never been my goal as I
> do lots of userspace programming as well. The end game for me is to
> replace QEMU/VirtualBox for Linux on Linux virtualization for my day to
> day purposes.

Maybe it should be in tools/pekka then.  Usually subsystems that want to
be merged into Linux have broaded audiences though.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Avi,

On Sun, 2011-11-06 at 12:23 +0200, Avi Kivity wrote:
> > If this is a serious attempt in making QEMU command line suck less on
> > Linux, I think it makes sense to do this properly instead of adding a
> > niche script to the kernel tree that's simply going to bit rot over
> > time.
> 
> You misunderstand.  This is an attempt to address the requirements of a
> niche population, kernel developers and testers, not to improve the qemu
> command line.  For the majority of qemu installations, this script is
> useless.

Right.

On Sun, 2011-11-06 at 12:23 +0200, Avi Kivity wrote:
> In most installations, qemu is driven by other programs, so any changes
> to the command line would be invisible, except insofar as they break things.
> 
> For the occasional direct user of qemu, something like 'qemu-kvm -m 1G
> /images/blah.img' is enough to boot an image.  This script doesn't help
> in any way.
> 
> This script is for kernel developers who don't want to bother with
> setting up a disk image (which, btw, many are still required to do - I'm
> guessing most kernel developers who use qemu are cross-arch).  It has
> limited scope and works mostly by hiding qemu features.  As such it
> doesn't belong in qemu.

I'm certainly not against merging the script if people are actually
using it and it solves their problem.

I personally find the whole exercise pointless because it's not
attempting to solve any of the fundamental issues QEMU command line
interface has nor does it try to make Linux on Linux virtualization
simpler and more integrated.

People seem to think the KVM tool is only about solving a specific
problem to kernel developers. That's certainly never been my goal as I
do lots of userspace programming as well. The end game for me is to
replace QEMU/VirtualBox for Linux on Linux virtualization for my day to
day purposes.

			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Avi,

On Sun, 2011-11-06 at 12:23 +0200, Avi Kivity wrote:
> > If this is a serious attempt in making QEMU command line suck less on
> > Linux, I think it makes sense to do this properly instead of adding a
> > niche script to the kernel tree that's simply going to bit rot over
> > time.
> 
> You misunderstand.  This is an attempt to address the requirements of a
> niche population, kernel developers and testers, not to improve the qemu
> command line.  For the majority of qemu installations, this script is
> useless.

Right.

On Sun, 2011-11-06 at 12:23 +0200, Avi Kivity wrote:
> In most installations, qemu is driven by other programs, so any changes
> to the command line would be invisible, except insofar as they break things.
> 
> For the occasional direct user of qemu, something like 'qemu-kvm -m 1G
> /images/blah.img' is enough to boot an image.  This script doesn't help
> in any way.
> 
> This script is for kernel developers who don't want to bother with
> setting up a disk image (which, btw, many are still required to do - I'm
> guessing most kernel developers who use qemu are cross-arch).  It has
> limited scope and works mostly by hiding qemu features.  As such it
> doesn't belong in qemu.

I'm certainly not against merging the script if people are actually
using it and it solves their problem.

I personally find the whole exercise pointless because it's not
attempting to solve any of the fundamental issues QEMU command line
interface has nor does it try to make Linux on Linux virtualization
simpler and more integrated.

People seem to think the KVM tool is only about solving a specific
problem to kernel developers. That's certainly never been my goal as I
do lots of userspace programming as well. The end game for me is to
replace QEMU/VirtualBox for Linux on Linux virtualization for my day to
day purposes.

			Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 12:12 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 12:07 PM, Avi Kivity <avi@redhat.com> wrote:
> >> I'm happy to see some real competition for the KVM tool in usability. ;-)
> >>
> >> That said, while the script looks really useful for developers,
> >> wouldn't it make more sense to put it in QEMU to make sure it's kept
> >> up-to-date and distributions can pick it up too? (And yes, I realize
> >> the irony here.)
> >
> > Why would distributions want it?  It's only useful for kernel developers.
>
> It's useful for kernel testers too.

Well, they usually have a kernel with them.

> If this is a serious attempt in making QEMU command line suck less on
> Linux, I think it makes sense to do this properly instead of adding a
> niche script to the kernel tree that's simply going to bit rot over
> time.

You misunderstand.  This is an attempt to address the requirements of a
niche population, kernel developers and testers, not to improve the qemu
command line.  For the majority of qemu installations, this script is
useless.

In most installations, qemu is driven by other programs, so any changes
to the command line would be invisible, except insofar as they break things.

For the occasional direct user of qemu, something like 'qemu-kvm -m 1G
/images/blah.img' is enough to boot an image.  This script doesn't help
in any way.

This script is for kernel developers who don't want to bother with
setting up a disk image (which, btw, many are still required to do - I'm
guessing most kernel developers who use qemu are cross-arch).  It has
limited scope and works mostly by hiding qemu features.  As such it
doesn't belong in qemu.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 12:12 PM, Pekka Enberg wrote:
> On Sun, Nov 6, 2011 at 12:07 PM, Avi Kivity <avi@redhat.com> wrote:
> >> I'm happy to see some real competition for the KVM tool in usability. ;-)
> >>
> >> That said, while the script looks really useful for developers,
> >> wouldn't it make more sense to put it in QEMU to make sure it's kept
> >> up-to-date and distributions can pick it up too? (And yes, I realize
> >> the irony here.)
> >
> > Why would distributions want it?  It's only useful for kernel developers.
>
> It's useful for kernel testers too.

Well, they usually have a kernel with them.

> If this is a serious attempt in making QEMU command line suck less on
> Linux, I think it makes sense to do this properly instead of adding a
> niche script to the kernel tree that's simply going to bit rot over
> time.

You misunderstand.  This is an attempt to address the requirements of a
niche population, kernel developers and testers, not to improve the qemu
command line.  For the majority of qemu installations, this script is
useless.

In most installations, qemu is driven by other programs, so any changes
to the command line would be invisible, except insofar as they break things.

For the occasional direct user of qemu, something like 'qemu-kvm -m 1G
/images/blah.img' is enough to boot an image.  This script doesn't help
in any way.

This script is for kernel developers who don't want to bother with
setting up a disk image (which, btw, many are still required to do - I'm
guessing most kernel developers who use qemu are cross-arch).  It has
limited scope and works mostly by hiding qemu features.  As such it
doesn't belong in qemu.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 12:07 PM, Avi Kivity <avi@redhat.com> wrote:
>> I'm happy to see some real competition for the KVM tool in usability. ;-)
>>
>> That said, while the script looks really useful for developers,
>> wouldn't it make more sense to put it in QEMU to make sure it's kept
>> up-to-date and distributions can pick it up too? (And yes, I realize
>> the irony here.)
>
> Why would distributions want it?  It's only useful for kernel developers.

It's useful for kernel testers too.

If this is a serious attempt in making QEMU command line suck less on
Linux, I think it makes sense to do this properly instead of adding a
niche script to the kernel tree that's simply going to bit rot over
time.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

On Sun, Nov 6, 2011 at 12:07 PM, Avi Kivity <avi@redhat.com> wrote:
>> I'm happy to see some real competition for the KVM tool in usability. ;-)
>>
>> That said, while the script looks really useful for developers,
>> wouldn't it make more sense to put it in QEMU to make sure it's kept
>> up-to-date and distributions can pick it up too? (And yes, I realize
>> the irony here.)
>
> Why would distributions want it?  It's only useful for kernel developers.

It's useful for kernel testers too.

If this is a serious attempt in making QEMU command line suck less on
Linux, I think it makes sense to do this properly instead of adding a
niche script to the kernel tree that's simply going to bit rot over
time.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 12:04 PM, Pekka Enberg wrote:
> Hi Alexander,
>
> On Sun, Nov 6, 2011 at 3:35 AM, Alexander Graf <agraf@suse.de> wrote:
> > On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> > would be doing and what he expects from it. Basically he wants a
> > small and simple tool he and other developers can run to try out and
> > see if the kernel they just built actually works.
> >
> > Fortunately, QEMU can do that today already! The only piece that was
> > missing was the "simple" piece of the equation, so here is a script
> > that wraps around QEMU and executes a kernel you just built.
>
> I'm happy to see some real competition for the KVM tool in usability. ;-)
>
> That said, while the script looks really useful for developers,
> wouldn't it make more sense to put it in QEMU to make sure it's kept
> up-to-date and distributions can pick it up too? (And yes, I realize
> the irony here.)

Why would distributions want it?  It's only useful for kernel developers.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Avi Kivity]

On 11/06/2011 12:04 PM, Pekka Enberg wrote:
> Hi Alexander,
>
> On Sun, Nov 6, 2011 at 3:35 AM, Alexander Graf <agraf@suse.de> wrote:
> > On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> > would be doing and what he expects from it. Basically he wants a
> > small and simple tool he and other developers can run to try out and
> > see if the kernel they just built actually works.
> >
> > Fortunately, QEMU can do that today already! The only piece that was
> > missing was the "simple" piece of the equation, so here is a script
> > that wraps around QEMU and executes a kernel you just built.
>
> I'm happy to see some real competition for the KVM tool in usability. ;-)
>
> That said, while the script looks really useful for developers,
> wouldn't it make more sense to put it in QEMU to make sure it's kept
> up-to-date and distributions can pick it up too? (And yes, I realize
> the irony here.)

Why would distributions want it?  It's only useful for kernel developers.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Alexander,

On Sun, Nov 6, 2011 at 3:35 AM, Alexander Graf <agraf@suse.de> wrote:
> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> would be doing and what he expects from it. Basically he wants a
> small and simple tool he and other developers can run to try out and
> see if the kernel they just built actually works.
>
> Fortunately, QEMU can do that today already! The only piece that was
> missing was the "simple" piece of the equation, so here is a script
> that wraps around QEMU and executes a kernel you just built.

I'm happy to see some real competition for the KVM tool in usability. ;-)

That said, while the script looks really useful for developers,
wouldn't it make more sense to put it in QEMU to make sure it's kept
up-to-date and distributions can pick it up too? (And yes, I realize
the irony here.)

                        Pekka

Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Pekka Enberg]

Hi Alexander,

On Sun, Nov 6, 2011 at 3:35 AM, Alexander Graf <agraf@suse.de> wrote:
> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> would be doing and what he expects from it. Basically he wants a
> small and simple tool he and other developers can run to try out and
> see if the kernel they just built actually works.
>
> Fortunately, QEMU can do that today already! The only piece that was
> missing was the "simple" piece of the equation, so here is a script
> that wraps around QEMU and executes a kernel you just built.

I'm happy to see some real competition for the KVM tool in usability. ;-)

That said, while the script looks really useful for developers,
wouldn't it make more sense to put it in QEMU to make sure it's kept
up-to-date and distributions can pick it up too? (And yes, I realize
the irony here.)

                        Pekka

[PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
would be doing and what he expects from it. Basically he wants a
small and simple tool he and other developers can run to try out and
see if the kernel they just built actually works.

Fortunately, QEMU can do that today already! The only piece that was
missing was the "simple" piece of the equation, so here is a script
that wraps around QEMU and executes a kernel you just built.

If you do have KVM around and are not cross-compiling, it will use
KVM. But if you don't, you can still fall back to emulation mode and
at least check if your kernel still does what you expect. I only
implemented support for s390x and ppc there, but it's easily extensible
to more platforms, as QEMU can emulate (and virtualize) pretty much
any platform out there.

If you don't have qemu installed, please do so before using this script. Your
distro should provide a package for it (might even call it "kvm"). If not,
just compile it from source - it's not hard!

To quickly get going, just execute the following as user:

    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash

This will drop you into a shell on your rootfs.

Happy hacking!

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - fix naming of QEMU
  - use grep -q for has_config
  - support multiple -a args
  - spawn gdb on execution
  - pass through qemu options
  - dont use qemu-system-x86_64 on i386
  - add funny sentence to startup text
  - more helpful error messages

v2 -> v3:

  - move to tools/testing
  - fix running: message

  ( sorry for sending this version so late - I got caught up in
    random other stuff )

---
 tools/testing/run-qemu/run-qemu.sh |  338 ++++++++++++++++++++++++++++++++++++
 1 files changed, 338 insertions(+), 0 deletions(-)
 create mode 100755 tools/testing/run-qemu/run-qemu.sh

diff --git a/tools/testing/run-qemu/run-qemu.sh b/tools/testing/run-qemu/run-qemu.sh
new file mode 100755
index 0000000..70f194f
--- /dev/null
+++ b/tools/testing/run-qemu/run-qemu.sh
@@ -0,0 +1,338 @@
+#!/bin/bash
+#
+# QEMU Launcher
+#
+# This script enables simple use of the KVM and QEMU tool stack for
+# easy kernel testing. It allows to pass either a host directory to
+# the guest or a disk image. Example usage:
+#
+# Run the host root fs inside a VM:
+#
+# $ ./scripts/run-qemu.sh -r /
+#
+# Run the same with SDL:
+#
+# $ ./scripts/run-qemu.sh -r / --sdl
+# 
+# Or with a PPC build:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r /
+# 
+# PPC with a mac99 model by passing options to QEMU:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+#
+
+USE_SDL=
+USE_VNC=
+USE_GDB=1
+KERNEL_BIN=arch/x86/boot/bzImage
+MON_STDIO=
+KERNEL_APPEND2=
+SERIAL=ttyS0
+SERIAL_KCONFIG=SERIAL_8250
+BASENAME=$(basename "$0")
+
+function usage() {
+	echo "
+$BASENAME allows you to execute a virtual machine with the Linux kernel
+that you just built. To only execute a simple VM, you can just run it
+on your root fs with \"-r / -a init=/bin/bash\"
+
+	-a, --append parameters
+		Append the given parameters to the kernel command line.
+
+	-d, --disk image
+		Add the image file as disk into the VM.
+
+	-D, --no-gdb
+		Don't run an xterm with gdb attached to the guest.
+
+	-r, --root directory
+		Use the specified directory as root directory inside the guest.
+
+	-s, --sdl
+		Enable SDL graphical output.
+
+	-S, --smp cpus
+		Set number of virtual CPUs.
+
+	-v, --vnc
+		Enable VNC graphical output.
+
+Examples:
+
+	Run the host root fs inside a VM:
+	$ ./scripts/run-qemu.sh -r /
+
+	Run the same with SDL:
+	$ ./scripts/run-qemu.sh -r / --sdl
+	
+	Or with a PPC build:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r /
+	
+	PPC with a mac99 model by passing options to QEMU:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+"
+}
+
+function require_config() {
+	if [ "$(grep CONFIG_$1=y .config)" ]; then
+		return
+	fi
+
+	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
+	exit 1
+}
+
+function has_config() {
+	grep -q "CONFIG_$1=y" .config
+}
+
+function drive_if() {
+	if has_config VIRTIO_BLK; then
+		echo virtio
+	elif has_config ATA_PIIX; then
+		echo ide
+	else
+		echo "\
+Your kernel must have either VIRTIO_BLK or ATA_PIIX
+enabled for block device assignment" >&2
+		exit 1
+	fi
+}
+
+GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
+	-n "$(basename \"$0\")" -- "$@"`
+
+if [ $? != 0 ]; then
+	echo "Terminating..." >&2
+	exit 1
+fi
+
+eval set -- "$GETOPT"
+
+while true; do
+	case "$1" in
+	-a|--append)
+		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
+		shift
+		;;
+	-d|--disk)
+		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
+			file=$2,if=$(drive_if),cache=unsafe"
+		USE_DISK=1
+		shift
+		;;
+	-D|--no-gdb)
+		USE_GDB=
+		;;
+	-h|--help)
+		usage
+		exit 0
+		;;
+	-r|--root)
+		ROOTFS="$2"
+		shift
+		;;
+	-s|--sdl)
+		USE_SDL=1
+		;;
+	-S|--smp)
+		SMP="$2"
+		shift
+		;;
+	-v|--vnc)
+		USE_VNC=1
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		echo "Could not parse option: $1" >&2
+		exit 1
+		;;
+	esac
+	shift
+done
+
+if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
+	echo "\
+Error: Please specify at least -r or -d with a target \
+FS to run off of" >&2
+	exit 1
+fi
+
+# Try to find the KVM accelerated QEMU binary
+
+[ "$ARCH" ] || ARCH=$(uname -m)
+case $ARCH in
+x86_64)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	# QEMU's own build system calls it qemu-system-x86_64
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
+	;;
+i*86)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# i386 version of QEMU
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
+	;;
+s390*)
+	KERNEL_BIN=arch/s390/boot/image
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
+	;;
+ppc*)
+	KERNEL_BIN=vmlinux
+
+	IS_64BIT=
+	has_config PPC64 && IS_64BIT=64
+	if has_config PPC_85xx; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
+	elif has_config PPC_PSERIES; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
+		SERIAL=hvc0
+		SERIAL_KCONFIG=HVC_CONSOLE
+	elif has_config PPC_PMAC; then
+		has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
+		SERIAL_KCONFIG=SERIAL_PMACZILOG
+	else
+		echo "Unknown PPC board" >&2
+		exit 1
+	fi
+
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
+	;;
+esac
+
+if [ ! -e "$QEMU_BIN" ]; then
+	echo "\
+Could not find a usable QEMU binary. Please install one from \
+your distro or from source code using:
+
+  $ git clone git://git.qemu.org/qemu.git
+  $ cd qemu
+  $ ./configure
+  $ make -j
+  $ sudo make install
+" >&2
+	exit 1
+fi
+
+# The binaries without kvm in their name can be too old to support KVM, so
+# check for that before the user gets confused
+if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
+     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
+	echo "Your QEMU binary is too old, please update to at least 0.15." >&2
+	exit 1
+fi
+QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
+
+# We need to check some .config variables to make sure we actually work
+# on the respective kernel.
+if [ ! -e .config ]; then
+	echo "\
+Please run this script on a fully compiled and configured
+Linux kernel build directory" >&2
+	exit 1
+fi
+
+if [ ! -e "$KERNEL_BIN" ]; then
+	echo "Could not find kernel binary: $KERNEL_BIN" >&2
+	exit 1
+fi
+
+QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
+
+if [ "$USE_SDL" ]; then
+	# SDL is the default, so nothing to do
+	:
+elif [ "$USE_VNC" ]; then
+	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
+else
+	# When emulating a serial console, tell the kernel to use it as well
+	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
+	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
+	MON_STDIO=1
+	require_config "$SERIAL_KCONFIG"
+fi
+
+if [ "$ROOTFS" ]; then
+	# Using rootfs with 9p
+	require_config "NET_9P_VIRTIO"
+	KERNEL_APPEND="$KERNEL_APPEND \
+root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
+
+#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
+
+
+	QEMU_OPTIONS="$QEMU_OPTIONS \
+-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
+-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
+fi
+
+[ "$SMP" ] || SMP=1
+
+# User append args come last
+KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
+
+############### Execution #################
+
+QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
+
+echo "
+	################# Linux QEMU launcher #################
+
+This script executes your currently built Linux kernel using QEMU. If KVM is
+available, it will also use KVM for fast virtualization of your guest.
+
+The intent is to make it very easy to run your kernel. If you need to do more
+advanced things, such as passing through real devices, please use QEMU command
+line options and add them to the $BASENAME command line using --.
+
+This tool is for simplicity, not world dominating functionality coverage.
+(just a hobby, won't be big and professional like libvirt)
+
+"
+
+if [ "$MON_STDIO" ]; then
+	echo "\
+### Your guest is bound to the current foreground shell. To quit the guest, ###
+### please use Ctrl-A x                                                     ###
+"
+fi
+
+echo -n "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\" "
+for i in "$@"; do
+	echo -n "\"$i\" "
+done
+echo
+echo
+
+GDB_PID=
+if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
+	# Run a gdb console in parallel to the kernel
+
+	# XXX find out if port is in use
+	PORT=$(( $$ + 1024 ))
+	xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
+	GDB_PID=$!
+	QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
+fi
+
+$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
+wait $GDB_PID &>/dev/null
+
-- 
1.6.0.2

[PATCH] KVM: Add wrapper script around QEMU to test kernels

[Alexander Graf]

On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
would be doing and what he expects from it. Basically he wants a
small and simple tool he and other developers can run to try out and
see if the kernel they just built actually works.

Fortunately, QEMU can do that today already! The only piece that was
missing was the "simple" piece of the equation, so here is a script
that wraps around QEMU and executes a kernel you just built.

If you do have KVM around and are not cross-compiling, it will use
KVM. But if you don't, you can still fall back to emulation mode and
at least check if your kernel still does what you expect. I only
implemented support for s390x and ppc there, but it's easily extensible
to more platforms, as QEMU can emulate (and virtualize) pretty much
any platform out there.

If you don't have qemu installed, please do so before using this script. Your
distro should provide a package for it (might even call it "kvm"). If not,
just compile it from source - it's not hard!

To quickly get going, just execute the following as user:

    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash

This will drop you into a shell on your rootfs.

Happy hacking!

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - fix naming of QEMU
  - use grep -q for has_config
  - support multiple -a args
  - spawn gdb on execution
  - pass through qemu options
  - dont use qemu-system-x86_64 on i386
  - add funny sentence to startup text
  - more helpful error messages

v2 -> v3:

  - move to tools/testing
  - fix running: message

  ( sorry for sending this version so late - I got caught up in
    random other stuff )

---
 tools/testing/run-qemu/run-qemu.sh |  338 ++++++++++++++++++++++++++++++++++++
 1 files changed, 338 insertions(+), 0 deletions(-)
 create mode 100755 tools/testing/run-qemu/run-qemu.sh

diff --git a/tools/testing/run-qemu/run-qemu.sh b/tools/testing/run-qemu/run-qemu.sh
new file mode 100755
index 0000000..70f194f
--- /dev/null
+++ b/tools/testing/run-qemu/run-qemu.sh
@@ -0,0 +1,338 @@
+#!/bin/bash
+#
+# QEMU Launcher
+#
+# This script enables simple use of the KVM and QEMU tool stack for
+# easy kernel testing. It allows to pass either a host directory to
+# the guest or a disk image. Example usage:
+#
+# Run the host root fs inside a VM:
+#
+# $ ./scripts/run-qemu.sh -r /
+#
+# Run the same with SDL:
+#
+# $ ./scripts/run-qemu.sh -r / --sdl
+# 
+# Or with a PPC build:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r /
+# 
+# PPC with a mac99 model by passing options to QEMU:
+#
+# $ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+#
+
+USE_SDL=
+USE_VNC=
+USE_GDB=1
+KERNEL_BIN=arch/x86/boot/bzImage
+MON_STDIO=
+KERNEL_APPEND2=
+SERIAL=ttyS0
+SERIAL_KCONFIG=SERIAL_8250
+BASENAME=$(basename "$0")
+
+function usage() {
+	echo "
+$BASENAME allows you to execute a virtual machine with the Linux kernel
+that you just built. To only execute a simple VM, you can just run it
+on your root fs with \"-r / -a init=/bin/bash\"
+
+	-a, --append parameters
+		Append the given parameters to the kernel command line.
+
+	-d, --disk image
+		Add the image file as disk into the VM.
+
+	-D, --no-gdb
+		Don't run an xterm with gdb attached to the guest.
+
+	-r, --root directory
+		Use the specified directory as root directory inside the guest.
+
+	-s, --sdl
+		Enable SDL graphical output.
+
+	-S, --smp cpus
+		Set number of virtual CPUs.
+
+	-v, --vnc
+		Enable VNC graphical output.
+
+Examples:
+
+	Run the host root fs inside a VM:
+	$ ./scripts/run-qemu.sh -r /
+
+	Run the same with SDL:
+	$ ./scripts/run-qemu.sh -r / --sdl
+	
+	Or with a PPC build:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r /
+	
+	PPC with a mac99 model by passing options to QEMU:
+	$ ARCH=ppc ./scripts/run-qemu.sh -r / -- -M mac99
+"
+}
+
+function require_config() {
+	if [ "$(grep CONFIG_$1=y .config)" ]; then
+		return
+	fi
+
+	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
+	exit 1
+}
+
+function has_config() {
+	grep -q "CONFIG_$1=y" .config
+}
+
+function drive_if() {
+	if has_config VIRTIO_BLK; then
+		echo virtio
+	elif has_config ATA_PIIX; then
+		echo ide
+	else
+		echo "\
+Your kernel must have either VIRTIO_BLK or ATA_PIIX
+enabled for block device assignment" >&2
+		exit 1
+	fi
+}
+
+GETOPT=`getopt -o a:d:Dhr:sS:v --long append,disk:,no-gdb,help,root:,sdl,smp:,vnc \
+	-n "$(basename \"$0\")" -- "$@"`
+
+if [ $? != 0 ]; then
+	echo "Terminating..." >&2
+	exit 1
+fi
+
+eval set -- "$GETOPT"
+
+while true; do
+	case "$1" in
+	-a|--append)
+		KERNEL_APPEND2="$KERNEL_APPEND2 $KERNEL_APPEND2"
+		shift
+		;;
+	-d|--disk)
+		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
+			file=$2,if=$(drive_if),cache=unsafe"
+		USE_DISK=1
+		shift
+		;;
+	-D|--no-gdb)
+		USE_GDB=
+		;;
+	-h|--help)
+		usage
+		exit 0
+		;;
+	-r|--root)
+		ROOTFS="$2"
+		shift
+		;;
+	-s|--sdl)
+		USE_SDL=1
+		;;
+	-S|--smp)
+		SMP="$2"
+		shift
+		;;
+	-v|--vnc)
+		USE_VNC=1
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		echo "Could not parse option: $1" >&2
+		exit 1
+		;;
+	esac
+	shift
+done
+
+if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
+	echo "\
+Error: Please specify at least -r or -d with a target \
+FS to run off of" >&2
+	exit 1
+fi
+
+# Try to find the KVM accelerated QEMU binary
+
+[ "$ARCH" ] || ARCH=$(uname -m)
+case $ARCH in
+x86_64)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	# QEMU's own build system calls it qemu-system-x86_64
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
+	;;
+i*86)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# i386 version of QEMU
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
+	;;
+s390*)
+	KERNEL_BIN=arch/s390/boot/image
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
+	;;
+ppc*)
+	KERNEL_BIN=vmlinux
+
+	IS_64BIT=
+	has_config PPC64 && IS_64BIT=64
+	if has_config PPC_85xx; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
+	elif has_config PPC_PSERIES; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
+		SERIAL=hvc0
+		SERIAL_KCONFIG=HVC_CONSOLE
+	elif has_config PPC_PMAC; then
+		has_config SERIAL_PMACZILOG_TTYS || SERIAL=ttyPZ0
+		SERIAL_KCONFIG=SERIAL_PMACZILOG
+	else
+		echo "Unknown PPC board" >&2
+		exit 1
+	fi
+
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
+	;;
+esac
+
+if [ ! -e "$QEMU_BIN" ]; then
+	echo "\
+Could not find a usable QEMU binary. Please install one from \
+your distro or from source code using:
+
+  $ git clone git://git.qemu.org/qemu.git
+  $ cd qemu
+  $ ./configure
+  $ make -j
+  $ sudo make install
+" >&2
+	exit 1
+fi
+
+# The binaries without kvm in their name can be too old to support KVM, so
+# check for that before the user gets confused
+if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
+     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
+	echo "Your QEMU binary is too old, please update to at least 0.15." >&2
+	exit 1
+fi
+QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
+
+# We need to check some .config variables to make sure we actually work
+# on the respective kernel.
+if [ ! -e .config ]; then
+	echo "\
+Please run this script on a fully compiled and configured
+Linux kernel build directory" >&2
+	exit 1
+fi
+
+if [ ! -e "$KERNEL_BIN" ]; then
+	echo "Could not find kernel binary: $KERNEL_BIN" >&2
+	exit 1
+fi
+
+QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
+
+if [ "$USE_SDL" ]; then
+	# SDL is the default, so nothing to do
+	:
+elif [ "$USE_VNC" ]; then
+	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
+else
+	# When emulating a serial console, tell the kernel to use it as well
+	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
+	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
+	MON_STDIO=1
+	require_config "$SERIAL_KCONFIG"
+fi
+
+if [ "$ROOTFS" ]; then
+	# Using rootfs with 9p
+	require_config "NET_9P_VIRTIO"
+	KERNEL_APPEND="$KERNEL_APPEND \
+root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
+
+#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
+
+
+	QEMU_OPTIONS="$QEMU_OPTIONS \
+-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
+-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
+fi
+
+[ "$SMP" ] || SMP=1
+
+# User append args come last
+KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
+
+############### Execution #################
+
+QEMU_OPTIONS="$QEMU_OPTIONS -smp $SMP"
+
+echo "
+	################# Linux QEMU launcher #################
+
+This script executes your currently built Linux kernel using QEMU. If KVM is
+available, it will also use KVM for fast virtualization of your guest.
+
+The intent is to make it very easy to run your kernel. If you need to do more
+advanced things, such as passing through real devices, please use QEMU command
+line options and add them to the $BASENAME command line using --.
+
+This tool is for simplicity, not world dominating functionality coverage.
+(just a hobby, won't be big and professional like libvirt)
+
+"
+
+if [ "$MON_STDIO" ]; then
+	echo "\
+### Your guest is bound to the current foreground shell. To quit the guest, ###
+### please use Ctrl-A x                                                     ###
+"
+fi
+
+echo -n "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\" "
+for i in "$@"; do
+	echo -n "\"$i\" "
+done
+echo
+echo
+
+GDB_PID=
+if [ "$USE_GDB" -a "$DISPLAY" -a -x "$(which xterm)" -a -e "$(which gdb)" ]; then
+	# Run a gdb console in parallel to the kernel
+
+	# XXX find out if port is in use
+	PORT=$(( $$ + 1024 ))
+	xterm -T "$BASENAME" -e "sleep 2; gdb vmlinux -ex 'target remote localhost:$PORT' -ex c" &
+	GDB_PID=$!
+	QEMU_OPTIONS="$QEMU_OPTIONS -gdb tcp::$PORT"
+fi
+
+$QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND" "$@"
+wait $GDB_PID &>/dev/null
+
-- 
1.6.0.2

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Alexander Graf]

On 24.08.2011, at 20:44, Américo Wang wrote:

> On Thu, Aug 25, 2011 at 4:35 AM, Alexander Graf <agraf@suse.de> wrote:
>> 
>> On 24.08.2011, at 00:31, Américo Wang wrote:
>> 
>>> On Wed, Aug 24, 2011 at 1:19 PM, Pekka Enberg <penberg@kernel.org> wrote:
>>>> 
>>>> It's nice to see such an honest attempt at improving QEMU usability, Alexander!
>>>> 
>>>> One comment: in my experience, having shell scripts under
>>>> Documentation reduces the likelihood that people actually discover
>>>> them so you might want to consider putting it under scripts or tools.
>>>> 
>>> 
>>> I was going to give the same suggestion, +1 for tools/ directory.
>> 
>> Well, scripts/ is a flat directory where I can just throw in the script. Tools however is split by tool and creating a full new directory for only a single script sounds a bit like overkill to me. I'll move it to scripts/ for now :)
> 
> How about the directory tools/testing/ ?
> 
> scripts/ is mainly for the tools/utilities we use to build kernel or
> do kernel dev,
> it is not so suitable for your script IMHO.

Good idea! I talked to Steven about it as well and completely forgot your email pointing me to the same directory. I guess that one does fit it pretty well.


Alex

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Alexander Graf]

On 24.08.2011, at 20:44, Américo Wang wrote:

> On Thu, Aug 25, 2011 at 4:35 AM, Alexander Graf <agraf@suse.de> wrote:
>> 
>> On 24.08.2011, at 00:31, Américo Wang wrote:
>> 
>>> On Wed, Aug 24, 2011 at 1:19 PM, Pekka Enberg <penberg@kernel.org> wrote:
>>>> 
>>>> It's nice to see such an honest attempt at improving QEMU usability, Alexander!
>>>> 
>>>> One comment: in my experience, having shell scripts under
>>>> Documentation reduces the likelihood that people actually discover
>>>> them so you might want to consider putting it under scripts or tools.
>>>> 
>>> 
>>> I was going to give the same suggestion, +1 for tools/ directory.
>> 
>> Well, scripts/ is a flat directory where I can just throw in the script. Tools however is split by tool and creating a full new directory for only a single script sounds a bit like overkill to me. I'll move it to scripts/ for now :)
> 
> How about the directory tools/testing/ ?
> 
> scripts/ is mainly for the tools/utilities we use to build kernel or
> do kernel dev,
> it is not so suitable for your script IMHO.

Good idea! I talked to Steven about it as well and completely forgot your email pointing me to the same directory. I guess that one does fit it pretty well.


Alex

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Américo Wang]

On Thu, Aug 25, 2011 at 4:35 AM, Alexander Graf <agraf@suse.de> wrote:
>
> On 24.08.2011, at 00:31, Américo Wang wrote:
>
>> On Wed, Aug 24, 2011 at 1:19 PM, Pekka Enberg <penberg@kernel.org> wrote:
>>>
>>> It's nice to see such an honest attempt at improving QEMU usability, Alexander!
>>>
>>> One comment: in my experience, having shell scripts under
>>> Documentation reduces the likelihood that people actually discover
>>> them so you might want to consider putting it under scripts or tools.
>>>
>>
>> I was going to give the same suggestion, +1 for tools/ directory.
>
> Well, scripts/ is a flat directory where I can just throw in the script. Tools however is split by tool and creating a full new directory for only a single script sounds a bit like overkill to me. I'll move it to scripts/ for now :)

How about the directory tools/testing/ ?

scripts/ is mainly for the tools/utilities we use to build kernel or
do kernel dev,
it is not so suitable for your script IMHO.

Thanks.

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Américo Wang]

On Thu, Aug 25, 2011 at 4:35 AM, Alexander Graf <agraf@suse.de> wrote:
>
> On 24.08.2011, at 00:31, Américo Wang wrote:
>
>> On Wed, Aug 24, 2011 at 1:19 PM, Pekka Enberg <penberg@kernel.org> wrote:
>>>
>>> It's nice to see such an honest attempt at improving QEMU usability, Alexander!
>>>
>>> One comment: in my experience, having shell scripts under
>>> Documentation reduces the likelihood that people actually discover
>>> them so you might want to consider putting it under scripts or tools.
>>>
>>
>> I was going to give the same suggestion, +1 for tools/ directory.
>
> Well, scripts/ is a flat directory where I can just throw in the script. Tools however is split by tool and creating a full new directory for only a single script sounds a bit like overkill to me. I'll move it to scripts/ for now :)

How about the directory tools/testing/ ?

scripts/ is mainly for the tools/utilities we use to build kernel or
do kernel dev,
it is not so suitable for your script IMHO.

Thanks.

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Alexander Graf]

On 24.08.2011, at 04:16, Jan Kiszka wrote:

> On 2011-08-24 10:25, Avi Kivity wrote:
>> On 08/24/2011 01:16 AM, Alexander Graf wrote:
>>> +"
>>> +echo "\
>>> +Your guest is bound to the current foreground shell. To quit the guest,
>>> +please use Ctrl-A x"
>>> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\"
>>> -smp $SMP"
>>> +echo
>>> +
>>> +exec $QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND -smp $SMP"
>> 
>> Would be nice to support launching gdb in a separate terminal with
>> vmlinux already loaded, and already attached to qemu.
> 
> + loading a python script into gdb to pull in module symbols. There are
> a few implementations floating around (including my own one).

I'll leave that part to you then :). I haven't figured out a nice way how to get modules into the VM for now anyways.

> It would also be nice if one could append QEMU (note the capitalization
> BTW) options to the script, maybe everything after a '--' separator.

Good point :)


Alex

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Alexander Graf]

On 24.08.2011, at 04:16, Jan Kiszka wrote:

> On 2011-08-24 10:25, Avi Kivity wrote:
>> On 08/24/2011 01:16 AM, Alexander Graf wrote:
>>> +"
>>> +echo "\
>>> +Your guest is bound to the current foreground shell. To quit the guest,
>>> +please use Ctrl-A x"
>>> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\"
>>> -smp $SMP"
>>> +echo
>>> +
>>> +exec $QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND -smp $SMP"
>> 
>> Would be nice to support launching gdb in a separate terminal with
>> vmlinux already loaded, and already attached to qemu.
> 
> + loading a python script into gdb to pull in module symbols. There are
> a few implementations floating around (including my own one).

I'll leave that part to you then :). I haven't figured out a nice way how to get modules into the VM for now anyways.

> It would also be nice if one could append QEMU (note the capitalization
> BTW) options to the script, maybe everything after a '--' separator.

Good point :)


Alex

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Alexander Graf]

On 24.08.2011, at 00:31, Américo Wang wrote:

> On Wed, Aug 24, 2011 at 1:19 PM, Pekka Enberg <penberg@kernel.org> wrote:
>> 
>> It's nice to see such an honest attempt at improving QEMU usability, Alexander!
>> 
>> One comment: in my experience, having shell scripts under
>> Documentation reduces the likelihood that people actually discover
>> them so you might want to consider putting it under scripts or tools.
>> 
> 
> I was going to give the same suggestion, +1 for tools/ directory.

Well, scripts/ is a flat directory where I can just throw in the script. Tools however is split by tool and creating a full new directory for only a single script sounds a bit like overkill to me. I'll move it to scripts/ for now :)


Alex

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Alexander Graf]

On 24.08.2011, at 00:31, Américo Wang wrote:

> On Wed, Aug 24, 2011 at 1:19 PM, Pekka Enberg <penberg@kernel.org> wrote:
>> 
>> It's nice to see such an honest attempt at improving QEMU usability, Alexander!
>> 
>> One comment: in my experience, having shell scripts under
>> Documentation reduces the likelihood that people actually discover
>> them so you might want to consider putting it under scripts or tools.
>> 
> 
> I was going to give the same suggestion, +1 for tools/ directory.

Well, scripts/ is a flat directory where I can just throw in the script. Tools however is split by tool and creating a full new directory for only a single script sounds a bit like overkill to me. I'll move it to scripts/ for now :)


Alex

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Avi Kivity]

On 08/24/2011 08:40 PM, Blue Swirl wrote:
> >  +
> >  +       # Qemu's own build system calls it qemu-system-x86_64
> >  +       [ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
>
> If you run qemu-system-x86_64 on an i386 host, will it use kvm at all?

I think it will, and that's actually a bug, since kvm doesn't support 
virtualizing long mode on a 32-bit host.


-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Jan Kiszka]

On 2011-08-24 10:25, Avi Kivity wrote:
> On 08/24/2011 01:16 AM, Alexander Graf wrote:
>> +"
>> +echo "\
>> +Your guest is bound to the current foreground shell. To quit the guest,
>> +please use Ctrl-A x"
>> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\"
>> -smp $SMP"
>> +echo
>> +
>> +exec $QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND -smp $SMP"
> 
> Would be nice to support launching gdb in a separate terminal with
> vmlinux already loaded, and already attached to qemu.

+ loading a python script into gdb to pull in module symbols. There are
a few implementations floating around (including my own one).

It would also be nice if one could append QEMU (note the capitalization
BTW) options to the script, maybe everything after a '--' separator.

Jan

-- 
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Avi Kivity]

On 08/24/2011 01:16 AM, Alexander Graf wrote:
> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> would be doing and what he expects from it. Basically he wants a
> small and simple tool he and other developers can run to try out and
> see if the kernel they just built actually works.
>
> Fortunately, Qemu can do that today already! The only piece that was
> missing was the "simple" piece of the equation, so here is a script
> that wraps around Qemu and executes a kernel you just built.
>
> If you do have KVM around and are not cross-compiling, it will use
> KVM. But if you don't, you can still fall back to emulation mode and
> at least check if your kernel still does what you expect. I only
> implemented support for s390x and ppc there, but it's easily extensible
> to more platforms, as Qemu can emulate (and virtualize) pretty much
> any platform out there.
>
> If you don't have qemu installed, please do so before using this script. Your
> distro should provide a package for it (might even call it "kvm"). If not,
> just compile it from source - it's not hard!
>
> To quickly get going, just execute the following as user:
>
>      $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>
> This will drop you into a shell on your rootfs.
>
> Happy hacking!
>
> +
> +function has_config() {
> +	grep "CONFIG_$1=y" .config
> +}

grep -q ?

> +	case "$1" in
> +	-a|--append)
> +		KERNEL_APPEND2="$2"

Might want to append to KERNEL_APPEND2, so you could have multiple -a args.

> +echo "
> +	################# Linux Qemu launcher #################
> +
> +This script executes your currently built Linux kernel using Qemu. If KVM is
> +available, it will also use KVM for fast virtualization of your guest.
> +
> +The intent is to make it very easy to run your kernel. If you need to do more
> +advanced things, such as passing through real devices, please take the command
> +line shown below and modify it to your needs. This tool is for simplicity, not
> +world dominating functionality coverage.

Device assignment could be useful for driver developers, yes.

> +"
> +echo "\
> +Your guest is bound to the current foreground shell. To quit the guest,
> +please use Ctrl-A x"
> +echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\" -smp $SMP"
> +echo
> +
> +exec $QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND -smp $SMP"

Would be nice to support launching gdb in a separate terminal with 
vmlinux already loaded, and already attached to qemu.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Américo Wang]

On Wed, Aug 24, 2011 at 1:19 PM, Pekka Enberg <penberg@kernel.org> wrote:
>
> It's nice to see such an honest attempt at improving QEMU usability, Alexander!
>
> One comment: in my experience, having shell scripts under
> Documentation reduces the likelihood that people actually discover
> them so you might want to consider putting it under scripts or tools.
>

I was going to give the same suggestion, +1 for tools/ directory.

Thanks!

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Américo Wang]

On Wed, Aug 24, 2011 at 1:19 PM, Pekka Enberg <penberg@kernel.org> wrote:
>
> It's nice to see such an honest attempt at improving QEMU usability, Alexander!
>
> One comment: in my experience, having shell scripts under
> Documentation reduces the likelihood that people actually discover
> them so you might want to consider putting it under scripts or tools.
>

I was going to give the same suggestion, +1 for tools/ directory.

Thanks!

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Pekka Enberg]

On Wed, Aug 24, 2011 at 1:16 AM, Alexander Graf <agraf@suse.de> wrote:
> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> would be doing and what he expects from it. Basically he wants a
> small and simple tool he and other developers can run to try out and
> see if the kernel they just built actually works.
>
> Fortunately, Qemu can do that today already! The only piece that was
> missing was the "simple" piece of the equation, so here is a script
> that wraps around Qemu and executes a kernel you just built.
>
> If you do have KVM around and are not cross-compiling, it will use
> KVM. But if you don't, you can still fall back to emulation mode and
> at least check if your kernel still does what you expect. I only
> implemented support for s390x and ppc there, but it's easily extensible
> to more platforms, as Qemu can emulate (and virtualize) pretty much
> any platform out there.
>
> If you don't have qemu installed, please do so before using this script. Your
> distro should provide a package for it (might even call it "kvm"). If not,
> just compile it from source - it's not hard!
>
> To quickly get going, just execute the following as user:
>
>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>
> This will drop you into a shell on your rootfs.
>
> Happy hacking!

It's nice to see such an honest attempt at improving QEMU usability, Alexander!

One comment: in my experience, having shell scripts under
Documentation reduces the likelihood that people actually discover
them so you might want to consider putting it under scripts or tools.

                        Pekka

Re: [PATCH] KVM: Add wrapper script around Qemu to test kernels

[Pekka Enberg]

On Wed, Aug 24, 2011 at 1:16 AM, Alexander Graf <agraf@suse.de> wrote:
> On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
> would be doing and what he expects from it. Basically he wants a
> small and simple tool he and other developers can run to try out and
> see if the kernel they just built actually works.
>
> Fortunately, Qemu can do that today already! The only piece that was
> missing was the "simple" piece of the equation, so here is a script
> that wraps around Qemu and executes a kernel you just built.
>
> If you do have KVM around and are not cross-compiling, it will use
> KVM. But if you don't, you can still fall back to emulation mode and
> at least check if your kernel still does what you expect. I only
> implemented support for s390x and ppc there, but it's easily extensible
> to more platforms, as Qemu can emulate (and virtualize) pretty much
> any platform out there.
>
> If you don't have qemu installed, please do so before using this script. Your
> distro should provide a package for it (might even call it "kvm"). If not,
> just compile it from source - it's not hard!
>
> To quickly get going, just execute the following as user:
>
>    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>
> This will drop you into a shell on your rootfs.
>
> Happy hacking!

It's nice to see such an honest attempt at improving QEMU usability, Alexander!

One comment: in my experience, having shell scripts under
Documentation reduces the likelihood that people actually discover
them so you might want to consider putting it under scripts or tools.

                        Pekka

[PATCH] KVM: Add wrapper script around Qemu to test kernels

[Alexander Graf]

On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
would be doing and what he expects from it. Basically he wants a
small and simple tool he and other developers can run to try out and
see if the kernel they just built actually works.

Fortunately, Qemu can do that today already! The only piece that was
missing was the "simple" piece of the equation, so here is a script
that wraps around Qemu and executes a kernel you just built.

If you do have KVM around and are not cross-compiling, it will use
KVM. But if you don't, you can still fall back to emulation mode and
at least check if your kernel still does what you expect. I only
implemented support for s390x and ppc there, but it's easily extensible
to more platforms, as Qemu can emulate (and virtualize) pretty much
any platform out there.

If you don't have qemu installed, please do so before using this script. Your
distro should provide a package for it (might even call it "kvm"). If not,
just compile it from source - it's not hard!

To quickly get going, just execute the following as user:

    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash

This will drop you into a shell on your rootfs.

Happy hacking!

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 Documentation/run-qemu.sh |  284 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 284 insertions(+), 0 deletions(-)
 create mode 100755 Documentation/run-qemu.sh

diff --git a/Documentation/run-qemu.sh b/Documentation/run-qemu.sh
new file mode 100755
index 0000000..0bac924
--- /dev/null
+++ b/Documentation/run-qemu.sh
@@ -0,0 +1,284 @@
+#!/bin/bash
+#
+# QEMU Launcher
+#
+# This script enables simple use of the KVM and Qemu tool stack for
+# easy kernel testing. It allows to pass either a host directory to
+# the guest or a disk image. Example usage:
+#
+# Run the host root fs inside a VM:
+#
+# $ ./Documentation/run-qemu.sh -r /
+#
+# Run the same with SDL:
+#
+# $ ./Documentation/run-qemu.sh -r / --sdl
+# 
+# Or with a PPC build:
+#
+# $ ARCH=ppc ./Documentation/run-qemu.sh -r /
+# 
+#
+
+USE_SDL=
+USE_VNC=
+KERNEL_BIN=arch/x86/boot/bzImage
+MON_STDIO=
+KERNEL_APPEND2=
+SERIAL=ttyS0
+SERIAL_KCONFIG=SERIAL_8250
+
+function usage() {
+	echo "
+Run-Qemu allows you to execute a virtual machine with the Linux kernel
+that you just built. To only execute a simple VM, you can just run it
+on your root fs with \"-r / -a init=/bin/bash\"
+
+	-a, --append parameters
+		Append the given parameters to the kernel command line
+
+	-d, --disk image
+		Add the image file as disk into the VM
+
+	-r, --root directory
+		Use the specified directory as root directory inside the guest.
+
+	-s, --sdl
+		Enable SDL graphical output.
+
+	-S, --smp cpus
+		Set number of virtual CPUs
+
+	-v, --vnc
+		Enable VNC graphical output.
+
+Examples:
+
+	Run the host root fs inside a VM:
+	$ ./Documentation/run-qemu.sh -r /
+
+	Run the same with SDL:
+	$ ./Documentation/run-qemu.sh -r / --sdl
+	
+	Or with a PPC build:
+	$ ARCH=ppc ./Documentation/run-qemu.sh -r /
+"
+}
+
+function require_config() {
+	if [ "$(grep CONFIG_$1=y .config)" ]; then
+		return
+	fi
+
+	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
+	exit 1
+}
+
+function has_config() {
+	grep "CONFIG_$1=y" .config
+}
+
+function drive_if() {
+	if [ "$(has_config VIRTIO_BLK)" ]; then
+		echo virtio
+	elif [ "$(has_config ATA_PIIX)" ]; then
+		echo ide
+	else
+		echo "\
+Your kernel must have either VIRTIO_BLK or ATA_PIIX
+enabled for block device assignment" >&2
+		exit 1
+	fi
+}
+
+GETOPT=`getopt -o a:d:hr:sS:v --long append,disk:,help,root:,sdl,smp:,vnc \
+	-n "$(basename \"$0\")" -- "$@"`
+
+if [ $? != 0 ]; then
+	echo "Terminating..." >&2
+	exit 1
+fi
+
+eval set -- "$GETOPT"
+
+while true; do
+	case "$1" in
+	-a|--append)
+		KERNEL_APPEND2="$2"
+		shift 2
+		;;
+	-d|--disk)
+		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
+			file=$2,if=$(drive_if),cache=unsafe"
+		USE_DISK=1
+		shift 2
+		;;
+	-h|--help)
+		usage
+		exit 0
+		;;
+	-r|--root)
+		ROOTFS="$2"
+		shift 2
+		;;
+	-s|--sdl)
+		USE_SDL=1
+		shift
+		;;
+	-S|--smp)
+		SMP="$2"
+		shift 2
+		;;
+	-v|--vnc)
+		USE_VNC=1
+		shift
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		echo "Could not parse option: $1" >&2
+		exit 1
+		;;
+	esac
+done
+
+if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
+	echo "\
+Error: Please specify at least -r or -d with a target \
+FS to run off of" >&2
+	exit 1
+fi
+
+# Try to find the KVM accelerated Qemu binary
+
+[ "$ARCH" ] || ARCH=$(uname -m)
+case $ARCH in
+i*86|x86_64)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	# Qemu's own build system calls it qemu-system-x86_64
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
+
+	# i386 version of Qemu
+	if [ ! "$(has_config X86_64)" ]; then
+		[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
+	fi
+	;;
+s390*)
+	KERNEL_BIN=arch/s390/boot/image
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
+	;;
+ppc*)
+	KERNEL_BIN=vmlinux
+
+	IS_64BIT=
+	[ "$(has_config PPC64)" ] && IS_64BIT=64
+	if [ "$(has_config PPC_85xx)" ]; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
+	elif [ "$(has_config PPC_PSERIES)" ]; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
+		SERIAL=hvc0
+		SERIAL_KCONFIG=HVC_CONSOLE
+	elif [ "$(has_config PPC_PMAC)" ]; then
+		[ "$(has_config SERIAL_PMACZILOG_TTYS)" ] || SERIAL=ttyPZ0
+		SERIAL_KCONFIG=SERIAL_PMACZILOG
+	else
+		echo "Unknown PPC board" >&2
+		exit 1
+	fi
+
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
+	;;
+esac
+
+if [ ! "$QEMU_BIN" ]; then
+	echo "\
+Could not find a usable Qemu binary. Please install one from \
+your distro or from source code." >&2
+	exit 1
+fi
+
+# The binaries without kvm in their name can be too old to support KVM, so
+# check for that before the user gets confused
+if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
+     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
+	echo "Your Qemu binary is too old, please update to at least 0.15." >&2
+	exit 1
+fi
+QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
+
+# We need to check some .config variables to make sure we actually work
+# on the respective kernel.
+if [ ! -e .config ]; then
+	echo "\
+Please run this script on a fully compiled and configured
+Linux kernel build directory" >&2
+	exit 1
+fi
+
+if [ ! -e "$KERNEL_BIN" ]; then
+	echo "Could not find kernel binary: $KERNEL_BIN" >&2
+	exit 1
+fi
+
+QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
+
+if [ "$USE_SDL" ]; then
+	# SDL is the default, so nothing to do
+	:
+elif [ "$USE_VNC" ]; then
+	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
+else
+	# When emulating a serial console, tell the kernel to use it as well
+	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
+	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
+	MON_STDIO=1
+	require_config "$SERIAL_KCONFIG"
+fi
+
+if [ "$ROOTFS" ]; then
+	# Using rootfs with 9p
+	require_config "NET_9P_VIRTIO"
+	KERNEL_APPEND="$KERNEL_APPEND \
+root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
+
+#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
+
+
+	QEMU_OPTIONS="$QEMU_OPTIONS \
+-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
+-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
+fi
+
+[ "$SMP" ] || SMP=1
+
+# User append args come last
+KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
+
+############### Execution #################
+
+echo "
+	################# Linux Qemu launcher #################
+
+This script executes your currently built Linux kernel using Qemu. If KVM is
+available, it will also use KVM for fast virtualization of your guest.
+
+The intent is to make it very easy to run your kernel. If you need to do more
+advanced things, such as passing through real devices, please take the command
+line shown below and modify it to your needs. This tool is for simplicity, not
+world dominating functionality coverage.
+"
+echo "\
+Your guest is bound to the current foreground shell. To quit the guest,
+please use Ctrl-A x"
+echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\" -smp $SMP"
+echo
+
+exec $QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND -smp $SMP"
-- 
1.6.0.2

[PATCH] KVM: Add wrapper script around Qemu to test kernels

[Alexander Graf]

On LinuxCon I had a nice chat with Linus on what he thinks kvm-tool
would be doing and what he expects from it. Basically he wants a
small and simple tool he and other developers can run to try out and
see if the kernel they just built actually works.

Fortunately, Qemu can do that today already! The only piece that was
missing was the "simple" piece of the equation, so here is a script
that wraps around Qemu and executes a kernel you just built.

If you do have KVM around and are not cross-compiling, it will use
KVM. But if you don't, you can still fall back to emulation mode and
at least check if your kernel still does what you expect. I only
implemented support for s390x and ppc there, but it's easily extensible
to more platforms, as Qemu can emulate (and virtualize) pretty much
any platform out there.

If you don't have qemu installed, please do so before using this script. Your
distro should provide a package for it (might even call it "kvm"). If not,
just compile it from source - it's not hard!

To quickly get going, just execute the following as user:

    $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash

This will drop you into a shell on your rootfs.

Happy hacking!

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 Documentation/run-qemu.sh |  284 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 284 insertions(+), 0 deletions(-)
 create mode 100755 Documentation/run-qemu.sh

diff --git a/Documentation/run-qemu.sh b/Documentation/run-qemu.sh
new file mode 100755
index 0000000..0bac924
--- /dev/null
+++ b/Documentation/run-qemu.sh
@@ -0,0 +1,284 @@
+#!/bin/bash
+#
+# QEMU Launcher
+#
+# This script enables simple use of the KVM and Qemu tool stack for
+# easy kernel testing. It allows to pass either a host directory to
+# the guest or a disk image. Example usage:
+#
+# Run the host root fs inside a VM:
+#
+# $ ./Documentation/run-qemu.sh -r /
+#
+# Run the same with SDL:
+#
+# $ ./Documentation/run-qemu.sh -r / --sdl
+# 
+# Or with a PPC build:
+#
+# $ ARCH=ppc ./Documentation/run-qemu.sh -r /
+# 
+#
+
+USE_SDL=
+USE_VNC=
+KERNEL_BIN=arch/x86/boot/bzImage
+MON_STDIO=
+KERNEL_APPEND2=
+SERIAL=ttyS0
+SERIAL_KCONFIG=SERIAL_8250
+
+function usage() {
+	echo "
+Run-Qemu allows you to execute a virtual machine with the Linux kernel
+that you just built. To only execute a simple VM, you can just run it
+on your root fs with \"-r / -a init=/bin/bash\"
+
+	-a, --append parameters
+		Append the given parameters to the kernel command line
+
+	-d, --disk image
+		Add the image file as disk into the VM
+
+	-r, --root directory
+		Use the specified directory as root directory inside the guest.
+
+	-s, --sdl
+		Enable SDL graphical output.
+
+	-S, --smp cpus
+		Set number of virtual CPUs
+
+	-v, --vnc
+		Enable VNC graphical output.
+
+Examples:
+
+	Run the host root fs inside a VM:
+	$ ./Documentation/run-qemu.sh -r /
+
+	Run the same with SDL:
+	$ ./Documentation/run-qemu.sh -r / --sdl
+	
+	Or with a PPC build:
+	$ ARCH=ppc ./Documentation/run-qemu.sh -r /
+"
+}
+
+function require_config() {
+	if [ "$(grep CONFIG_$1=y .config)" ]; then
+		return
+	fi
+
+	echo "You need to enable CONFIG_$1 for run-qemu to work properly"
+	exit 1
+}
+
+function has_config() {
+	grep "CONFIG_$1=y" .config
+}
+
+function drive_if() {
+	if [ "$(has_config VIRTIO_BLK)" ]; then
+		echo virtio
+	elif [ "$(has_config ATA_PIIX)" ]; then
+		echo ide
+	else
+		echo "\
+Your kernel must have either VIRTIO_BLK or ATA_PIIX
+enabled for block device assignment" >&2
+		exit 1
+	fi
+}
+
+GETOPT=`getopt -o a:d:hr:sS:v --long append,disk:,help,root:,sdl,smp:,vnc \
+	-n "$(basename \"$0\")" -- "$@"`
+
+if [ $? != 0 ]; then
+	echo "Terminating..." >&2
+	exit 1
+fi
+
+eval set -- "$GETOPT"
+
+while true; do
+	case "$1" in
+	-a|--append)
+		KERNEL_APPEND2="$2"
+		shift 2
+		;;
+	-d|--disk)
+		QEMU_OPTIONS="$QEMU_OPTIONS -drive \
+			file=$2,if=$(drive_if),cache=unsafe"
+		USE_DISK=1
+		shift 2
+		;;
+	-h|--help)
+		usage
+		exit 0
+		;;
+	-r|--root)
+		ROOTFS="$2"
+		shift 2
+		;;
+	-s|--sdl)
+		USE_SDL=1
+		shift
+		;;
+	-S|--smp)
+		SMP="$2"
+		shift 2
+		;;
+	-v|--vnc)
+		USE_VNC=1
+		shift
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		echo "Could not parse option: $1" >&2
+		exit 1
+		;;
+	esac
+done
+
+if [ ! "$ROOTFS" -a ! "$USE_DISK" ]; then
+	echo "\
+Error: Please specify at least -r or -d with a target \
+FS to run off of" >&2
+	exit 1
+fi
+
+# Try to find the KVM accelerated Qemu binary
+
+[ "$ARCH" ] || ARCH=$(uname -m)
+case $ARCH in
+i*86|x86_64)
+	KERNEL_BIN=arch/x86/boot/bzImage
+	# SUSE and Red Hat call the binary qemu-kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-kvm 2>/dev/null)
+
+	# Debian and Gentoo call it kvm
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which kvm 2>/dev/null)
+
+	# Qemu's own build system calls it qemu-system-x86_64
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-x86_64 2>/dev/null)
+
+	# i386 version of Qemu
+	if [ ! "$(has_config X86_64)" ]; then
+		[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu 2>/dev/null)
+	fi
+	;;
+s390*)
+	KERNEL_BIN=arch/s390/boot/image
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-s390x 2>/dev/null)
+	;;
+ppc*)
+	KERNEL_BIN=vmlinux
+
+	IS_64BIT=
+	[ "$(has_config PPC64)" ] && IS_64BIT=64
+	if [ "$(has_config PPC_85xx)" ]; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M mpc8544ds"
+	elif [ "$(has_config PPC_PSERIES)" ]; then
+		QEMU_OPTIONS="$QEMU_OPTIONS -M pseries"
+		SERIAL=hvc0
+		SERIAL_KCONFIG=HVC_CONSOLE
+	elif [ "$(has_config PPC_PMAC)" ]; then
+		[ "$(has_config SERIAL_PMACZILOG_TTYS)" ] || SERIAL=ttyPZ0
+		SERIAL_KCONFIG=SERIAL_PMACZILOG
+	else
+		echo "Unknown PPC board" >&2
+		exit 1
+	fi
+
+	[ "$QEMU_BIN" ] || QEMU_BIN=$(which qemu-system-ppc${IS_64BIT} 2>/dev/null)
+	;;
+esac
+
+if [ ! "$QEMU_BIN" ]; then
+	echo "\
+Could not find a usable Qemu binary. Please install one from \
+your distro or from source code." >&2
+	exit 1
+fi
+
+# The binaries without kvm in their name can be too old to support KVM, so
+# check for that before the user gets confused
+if [ ! "$(echo $QEMU_BIN | grep kvm)" -a \
+     ! "$($QEMU_BIN --help | egrep '^-machine')" ]; then
+	echo "Your Qemu binary is too old, please update to at least 0.15." >&2
+	exit 1
+fi
+QEMU_OPTIONS="$QEMU_OPTIONS -machine accel=kvm:tcg"
+
+# We need to check some .config variables to make sure we actually work
+# on the respective kernel.
+if [ ! -e .config ]; then
+	echo "\
+Please run this script on a fully compiled and configured
+Linux kernel build directory" >&2
+	exit 1
+fi
+
+if [ ! -e "$KERNEL_BIN" ]; then
+	echo "Could not find kernel binary: $KERNEL_BIN" >&2
+	exit 1
+fi
+
+QEMU_OPTIONS="$QEMU_OPTIONS -kernel $KERNEL_BIN"
+
+if [ "$USE_SDL" ]; then
+	# SDL is the default, so nothing to do
+	:
+elif [ "$USE_VNC" ]; then
+	QEMU_OPTIONS="$QEMU_OPTIONS -vnc :5"
+else
+	# When emulating a serial console, tell the kernel to use it as well
+	QEMU_OPTIONS="$QEMU_OPTIONS -nographic"
+	KERNEL_APPEND="$KERNEL_APPEND console=$SERIAL earlyprintk=serial"
+	MON_STDIO=1
+	require_config "$SERIAL_KCONFIG"
+fi
+
+if [ "$ROOTFS" ]; then
+	# Using rootfs with 9p
+	require_config "NET_9P_VIRTIO"
+	KERNEL_APPEND="$KERNEL_APPEND \
+root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p"
+
+#Usage: -virtfs fstype,path=/share_path/,security_model=[mapped|passthrough|none],mount_tag=tag.
+
+
+	QEMU_OPTIONS="$QEMU_OPTIONS \
+-virtfs local,id=root,path=$ROOTFS,mount_tag=root,security_model=passthrough \
+-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root"
+fi
+
+[ "$SMP" ] || SMP=1
+
+# User append args come last
+KERNEL_APPEND="$KERNEL_APPEND $KERNEL_APPEND2"
+
+############### Execution #################
+
+echo "
+	################# Linux Qemu launcher #################
+
+This script executes your currently built Linux kernel using Qemu. If KVM is
+available, it will also use KVM for fast virtualization of your guest.
+
+The intent is to make it very easy to run your kernel. If you need to do more
+advanced things, such as passing through real devices, please take the command
+line shown below and modify it to your needs. This tool is for simplicity, not
+world dominating functionality coverage.
+"
+echo "\
+Your guest is bound to the current foreground shell. To quit the guest,
+please use Ctrl-A x"
+echo "  Executing: $QEMU_BIN $QEMU_OPTIONS -append \"$KERNEL_APPEND\" -smp $SMP"
+echo
+
+exec $QEMU_BIN $QEMU_OPTIONS -append "$KERNEL_APPEND -smp $SMP"
-- 
1.6.0.2