[PATCH for-5.1 0/4] Document virt and a few other Arm boards

[PATCH for-5.1 0/4] Document virt and a few other Arm boards

[Peter Maydell]

This series adds some documentation to the system manual for
previously undocumented Arm board types.

The first 3 patches are very minimalist documentation of the
canon-a1000, collie and gumstix board families.  The info was
obtained by looking at source code comments, a brief scan of what
kinds of devices the code was creating, and sometimes the cover
letter for the patch series that added the board. The level
of documentation here doesn't seem fantastically useful but
on the other hand it's no worse than that we have for some
existing boards (eg cheetah) and it would be nice to eventually
get to complete coverage of all the arm board types. But
I figured some feedback on whether this level of documentation
was worth doing was worthwhile before I tried to add it for
any of the other board types.

Finally, patch 4 is more meaty: it documents the "virt" board
(which was a pretty embarrassing omission from the docs given
that it is the standard board type that we recommend for
Arm guests these days). I have attempted to fold in the info
on the board from https://wiki.qemu.org/Documentation/Platforms/ARM
where appropriate.

Peter Maydell (4):
  docs/system: Briefly document canon-a1100 board
  docs/system: Briefly document collie board
  docs/system: Briefly document gumstix boards
  docs/system: Document the arm virt board

 docs/system/arm/collie.rst  |  16 ++++
 docs/system/arm/digic.rst   |  11 +++
 docs/system/arm/gumstix.rst |  21 +++++
 docs/system/arm/virt.rst    | 157 ++++++++++++++++++++++++++++++++++++
 docs/system/target-arm.rst  |   4 +
 MAINTAINERS                 |   4 +
 6 files changed, 213 insertions(+)
 create mode 100644 docs/system/arm/collie.rst
 create mode 100644 docs/system/arm/digic.rst
 create mode 100644 docs/system/arm/gumstix.rst
 create mode 100644 docs/system/arm/virt.rst

-- 
2.20.1

[PATCH for-5.1 1/4] docs/system: Briefly document canon-a1100 board

[Peter Maydell]

Add skeletal documentation of the canon-a1100 board.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 docs/system/arm/digic.rst  | 11 +++++++++++
 docs/system/target-arm.rst |  1 +
 MAINTAINERS                |  1 +
 3 files changed, 13 insertions(+)
 create mode 100644 docs/system/arm/digic.rst

diff --git a/docs/system/arm/digic.rst b/docs/system/arm/digic.rst
new file mode 100644
index 00000000000..2b3520ff5e1
--- /dev/null
+++ b/docs/system/arm/digic.rst
@@ -0,0 +1,11 @@
+Canon A1100 (``canon-a1100``)
+=============================
+
+This machine is a model of the Canon PowerShot A1100 camera, which
+uses the DIGIC SoC. This model is based on reverse engineering efforts
+by the contributors to the `CHDK <http://chdk.wikia.com/>`_ and
+`Magic Lantern <http://www.magiclantern.fm/>`_ projects.
+
+The emulation is incomplete. In particular it can't be used
+to run the original camera firmware, but it can successfully run
+an experimental version of the `barebox bootloader <http://www.barebox.org/>`_.
diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
index 1bd477a2936..8fa51a22817 100644
--- a/docs/system/target-arm.rst
+++ b/docs/system/target-arm.rst
@@ -82,6 +82,7 @@ undocumented; you can get a complete list by running
    arm/versatile
    arm/vexpress
    arm/aspeed
+   arm/digic
    arm/musicpal
    arm/nseries
    arm/orangepi
diff --git a/MAINTAINERS b/MAINTAINERS
index fe8139f3675..0f578040b99 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -634,6 +634,7 @@ F: include/hw/arm/digic.h
 F: hw/*/digic*
 F: include/hw/*/digic*
 F: tests/acceptance/machine_arm_canona1100.py
+F: docs/system/arm/digic.rst
 
 Goldfish RTC
 M: Anup Patel <anup.patel@wdc.com>
-- 
2.20.1

Re: [PATCH for-5.1 1/4] docs/system: Briefly document canon-a1100 board

[Philippe Mathieu-Daudé]

On 7/13/20 7:57 PM, Peter Maydell wrote:
> Add skeletal documentation of the canon-a1100 board.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  docs/system/arm/digic.rst  | 11 +++++++++++
>  docs/system/target-arm.rst |  1 +
>  MAINTAINERS                |  1 +
>  3 files changed, 13 insertions(+)
>  create mode 100644 docs/system/arm/digic.rst
> 
> diff --git a/docs/system/arm/digic.rst b/docs/system/arm/digic.rst
> new file mode 100644
> index 00000000000..2b3520ff5e1
> --- /dev/null
> +++ b/docs/system/arm/digic.rst
> @@ -0,0 +1,11 @@
> +Canon A1100 (``canon-a1100``)
> +=============================
> +
> +This machine is a model of the Canon PowerShot A1100 camera, which
> +uses the DIGIC SoC. This model is based on reverse engineering efforts
> +by the contributors to the `CHDK <http://chdk.wikia.com/>`_ and
> +`Magic Lantern <http://www.magiclantern.fm/>`_ projects.
> +
> +The emulation is incomplete. In particular it can't be used
> +to run the original camera firmware, but it can successfully run
> +an experimental version of the `barebox bootloader <http://www.barebox.org/>`_.
> diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
> index 1bd477a2936..8fa51a22817 100644
> --- a/docs/system/target-arm.rst
> +++ b/docs/system/target-arm.rst
> @@ -82,6 +82,7 @@ undocumented; you can get a complete list by running
>     arm/versatile
>     arm/vexpress
>     arm/aspeed
> +   arm/digic
>     arm/musicpal
>     arm/nseries
>     arm/orangepi
> diff --git a/MAINTAINERS b/MAINTAINERS
> index fe8139f3675..0f578040b99 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -634,6 +634,7 @@ F: include/hw/arm/digic.h
>  F: hw/*/digic*
>  F: include/hw/*/digic*
>  F: tests/acceptance/machine_arm_canona1100.py
> +F: docs/system/arm/digic.rst
>  
>  Goldfish RTC
>  M: Anup Patel <anup.patel@wdc.com>
> 

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Re: [PATCH for-5.1 1/4] docs/system: Briefly document canon-a1100 board

[Alex Bennée]

Peter Maydell <peter.maydell@linaro.org> writes:

> Add skeletal documentation of the canon-a1100 board.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

[PATCH for-5.1 2/4] docs/system: Briefly document collie board

[Peter Maydell]

Add skeletal documentation of the collie board.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 docs/system/arm/collie.rst | 16 ++++++++++++++++
 docs/system/target-arm.rst |  1 +
 MAINTAINERS                |  1 +
 3 files changed, 18 insertions(+)
 create mode 100644 docs/system/arm/collie.rst

diff --git a/docs/system/arm/collie.rst b/docs/system/arm/collie.rst
new file mode 100644
index 00000000000..9f8dbcad25d
--- /dev/null
+++ b/docs/system/arm/collie.rst
@@ -0,0 +1,16 @@
+Sharp Zaurus SL-5500 (``collie``)
+=================================
+
+This machine is a model of the Sharp Zaurus SL-5500, which is
+based on the StrongARM SA1110.
+
+Implemented devices:
+
+ * Flash
+ * Interrupt controller
+ * Timer
+ * RTC
+ * GPIO
+ * Peripheral Pin Controller (PPC)
+ * UARTs
+ * Synchronous Serial Ports (SSP)
diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
index 8fa51a22817..376c18f0b17 100644
--- a/docs/system/target-arm.rst
+++ b/docs/system/target-arm.rst
@@ -88,6 +88,7 @@ undocumented; you can get a complete list by running
    arm/orangepi
    arm/palm
    arm/xscale
+   arm/collie
    arm/sx1
    arm/stellaris
 
diff --git a/MAINTAINERS b/MAINTAINERS
index 0f578040b99..048b2d41729 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -845,6 +845,7 @@ L: qemu-arm@nongnu.org
 S: Odd Fixes
 F: hw/arm/collie.c
 F: hw/arm/strongarm*
+F: docs/system/arm/collie.rst
 
 Stellaris
 M: Peter Maydell <peter.maydell@linaro.org>
-- 
2.20.1

Re: [PATCH for-5.1 2/4] docs/system: Briefly document collie board

[Philippe Mathieu-Daudé]

On 7/13/20 7:57 PM, Peter Maydell wrote:
> Add skeletal documentation of the collie board.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  docs/system/arm/collie.rst | 16 ++++++++++++++++
>  docs/system/target-arm.rst |  1 +
>  MAINTAINERS                |  1 +
>  3 files changed, 18 insertions(+)
>  create mode 100644 docs/system/arm/collie.rst
> 
> diff --git a/docs/system/arm/collie.rst b/docs/system/arm/collie.rst
> new file mode 100644
> index 00000000000..9f8dbcad25d
> --- /dev/null
> +++ b/docs/system/arm/collie.rst
> @@ -0,0 +1,16 @@
> +Sharp Zaurus SL-5500 (``collie``)
> +=================================
> +
> +This machine is a model of the Sharp Zaurus SL-5500, which is
> +based on the StrongARM SA1110.
> +
> +Implemented devices:
> +
> + * Flash

Maybe "NOR flash".

Regardless:
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> + * Interrupt controller
> + * Timer
> + * RTC
> + * GPIO
> + * Peripheral Pin Controller (PPC)
> + * UARTs
> + * Synchronous Serial Ports (SSP)
> diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
> index 8fa51a22817..376c18f0b17 100644
> --- a/docs/system/target-arm.rst
> +++ b/docs/system/target-arm.rst
> @@ -88,6 +88,7 @@ undocumented; you can get a complete list by running
>     arm/orangepi
>     arm/palm
>     arm/xscale
> +   arm/collie
>     arm/sx1
>     arm/stellaris
>  
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0f578040b99..048b2d41729 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -845,6 +845,7 @@ L: qemu-arm@nongnu.org
>  S: Odd Fixes
>  F: hw/arm/collie.c
>  F: hw/arm/strongarm*
> +F: docs/system/arm/collie.rst
>  
>  Stellaris
>  M: Peter Maydell <peter.maydell@linaro.org>
> 

Re: [PATCH for-5.1 2/4] docs/system: Briefly document collie board

[Alex Bennée]

Peter Maydell <peter.maydell@linaro.org> writes:

> Add skeletal documentation of the collie board.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  docs/system/arm/collie.rst | 16 ++++++++++++++++
>  docs/system/target-arm.rst |  1 +
>  MAINTAINERS                |  1 +
>  3 files changed, 18 insertions(+)
>  create mode 100644 docs/system/arm/collie.rst
>
> diff --git a/docs/system/arm/collie.rst b/docs/system/arm/collie.rst
> new file mode 100644
> index 00000000000..9f8dbcad25d
> --- /dev/null
> +++ b/docs/system/arm/collie.rst
> @@ -0,0 +1,16 @@
> +Sharp Zaurus SL-5500 (``collie``)
> +=================================
> +
> +This machine is a model of the Sharp Zaurus SL-5500, which is
> +based on the StrongARM SA1110.

Maybe:

... Sharp Zaurus SL-5500, which was PDA in the 1990's based on the StrongARM SA1110.

just to make the class of hardware clearer.
<snip>

Either way:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

[PATCH for-5.1 3/4] docs/system: Briefly document gumstix boards

[Peter Maydell]

Add skeletal documentation of the gumstix boards
('connex' and 'verdex').

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 docs/system/arm/gumstix.rst | 21 +++++++++++++++++++++
 docs/system/target-arm.rst  |  1 +
 MAINTAINERS                 |  1 +
 3 files changed, 23 insertions(+)
 create mode 100644 docs/system/arm/gumstix.rst

diff --git a/docs/system/arm/gumstix.rst b/docs/system/arm/gumstix.rst
new file mode 100644
index 00000000000..805e0f8d5df
--- /dev/null
+++ b/docs/system/arm/gumstix.rst
@@ -0,0 +1,21 @@
+Gumstix Connex and Verdex (``connex``, ``verdex``)
+==================================================
+
+These machines model the Gumstix Connex and Verdex boards.
+The Connex has a PXA255 CPU and the Verdex has a PXA270.
+
+Implemented devices:
+
+ * Flash
+ * SMC91C111 ethernet
+ * Interrupt controller
+ * DMA
+ * Timer
+ * GPIO
+ * MMC/SD card
+ * FIR
+ * LCDC
+ * SSP
+ * PC Card sockets
+ * I2C
+ * I2S
diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
index 376c18f0b17..163ab915592 100644
--- a/docs/system/target-arm.rst
+++ b/docs/system/target-arm.rst
@@ -84,6 +84,7 @@ undocumented; you can get a complete list by running
    arm/aspeed
    arm/digic
    arm/musicpal
+   arm/gumstix
    arm/nseries
    arm/orangepi
    arm/palm
diff --git a/MAINTAINERS b/MAINTAINERS
index 048b2d41729..286b076da89 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -650,6 +650,7 @@ R: Philippe Mathieu-Daudé <f4bug@amsat.org>
 L: qemu-arm@nongnu.org
 S: Odd Fixes
 F: hw/arm/gumstix.c
+F: docs/system/arm/gumstix.rst
 
 i.MX25 PDK
 M: Peter Maydell <peter.maydell@linaro.org>
-- 
2.20.1

Re: [PATCH for-5.1 3/4] docs/system: Briefly document gumstix boards

[Philippe Mathieu-Daudé]

On 7/13/20 7:57 PM, Peter Maydell wrote:
> Add skeletal documentation of the gumstix boards
> ('connex' and 'verdex').
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  docs/system/arm/gumstix.rst | 21 +++++++++++++++++++++
>  docs/system/target-arm.rst  |  1 +
>  MAINTAINERS                 |  1 +
>  3 files changed, 23 insertions(+)
>  create mode 100644 docs/system/arm/gumstix.rst
> 
> diff --git a/docs/system/arm/gumstix.rst b/docs/system/arm/gumstix.rst
> new file mode 100644
> index 00000000000..805e0f8d5df
> --- /dev/null
> +++ b/docs/system/arm/gumstix.rst
> @@ -0,0 +1,21 @@
> +Gumstix Connex and Verdex (``connex``, ``verdex``)
> +==================================================
> +
> +These machines model the Gumstix Connex and Verdex boards.
> +The Connex has a PXA255 CPU and the Verdex has a PXA270.
> +
> +Implemented devices:
> +
> + * Flash

Maybe "NOR flash"?

> + * SMC91C111 ethernet
> + * Interrupt controller

Most of the peripherals are controllers =)
This sounds better then raw 'interrupts'.

> + * DMA
> + * Timer
> + * GPIO
> + * MMC/SD card
> + * FIR

'Fast Infra-Red communications port'?

> + * LCDC

'LCD controller'

> + * SSP

I think only SPI is implemented.

Maybe: 'Synchronous Serial Ports (SPI)'

> + * PC Card sockets

'PCMCIA interface'?

> + * I2C
> + * I2S
> diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
> index 376c18f0b17..163ab915592 100644
> --- a/docs/system/target-arm.rst
> +++ b/docs/system/target-arm.rst
> @@ -84,6 +84,7 @@ undocumented; you can get a complete list by running
>     arm/aspeed
>     arm/digic
>     arm/musicpal
> +   arm/gumstix
>     arm/nseries
>     arm/orangepi
>     arm/palm
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 048b2d41729..286b076da89 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -650,6 +650,7 @@ R: Philippe Mathieu-Daudé <f4bug@amsat.org>
>  L: qemu-arm@nongnu.org
>  S: Odd Fixes
>  F: hw/arm/gumstix.c
> +F: docs/system/arm/gumstix.rst

Feel free to take better descriptions or as it:
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

>  
>  i.MX25 PDK
>  M: Peter Maydell <peter.maydell@linaro.org>
> 

Re: [PATCH for-5.1 3/4] docs/system: Briefly document gumstix boards

[Alex Bennée]

Peter Maydell <peter.maydell@linaro.org> writes:

> Add skeletal documentation of the gumstix boards
> ('connex' and 'verdex').
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

[PATCH for-5.1 4/4] docs/system: Document the arm virt board

[Peter Maydell]

Document the arm 'virt' board, which has been undocumented
for far too long given that it is the main recommended board
type for arm guests.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 docs/system/arm/virt.rst   | 157 +++++++++++++++++++++++++++++++++++++
 docs/system/target-arm.rst |   1 +
 MAINTAINERS                |   1 +
 3 files changed, 159 insertions(+)
 create mode 100644 docs/system/arm/virt.rst

diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst
new file mode 100644
index 00000000000..6a7823d8bca
--- /dev/null
+++ b/docs/system/arm/virt.rst
@@ -0,0 +1,157 @@
+'virt' generic virtual platform (``virt``)
+==========================================
+
+The `virt` board is a platform which does not correspond to any
+real hardware; it is designed for use in virtual machines.
+It is the recommended board type if you simply want to run
+a guest such as Linux and do not care about reproducing the
+idiosyncrasies and limitations of a particular bit of real-world
+hardware.
+
+This is a "versioned" board model, so as well as the ``virt`` machine
+type itself (which may have improvements, bugfixes and other minor
+changes between QEMU versions) a version is provided that guarantees
+to have the same behaviour as that of previous QEMU releases, so
+that VM migration will work between QEMU versions. For instance the
+``virt-5.0`` machine type will behave like the ``virt`` machine from
+the QEMU 5.0 release, and migration should work between ``virt-5.0``
+of the 5.0 release and ``virt-5.0`` of the 5.1 release. Migration
+is not guaranteed to work between different QEMU releases for
+the non-versioned ``virt`` machine type.
+
+Supported devices
+"""""""""""""""""
+
+The virt board supports:
+
+- Flash memory
+- One PL011 UART
+- An RTC
+- The fw_cfg device that allows a guest to obtain data from QEMU
+- A PL061 GPIO controller
+- An optional SMMUv3 IOMMU
+- hotpluggable DIMMs
+- hotpluggable NVDIMs
+- 32 virtio-mmio transport devices
+- running guests using the KVM accelerator on aarch64 hardware
+- large amounts of RAM (at least 255GB, and more if using highmem)
+- many CPUs (up to 512 if using a GICv3 and highmem)
+- Secure-World-only devices if the CPU has TrustZone:
+
+  - A second PL011 UART
+  - A secure flash memory
+  - 16MB of secure RAM
+
+Supported guest CPU types:
+
+- ``cortex-a7`` (32-bit)
+- ``cortex-a15`` (32-bit; the default)
+- ``cortex-a53`` (64-bit)
+- ``cortex-a57`` (64-bit)
+- ``cortex-a72`` (64-bit)
+- ``host`` (with KVM only)
+- ``max`` (same as ``host`` for KVM; best possible emulation with TCG)
+
+Note that the default is ``cortex-a15``, so for an AArch64 guest you must
+specify a CPU type.
+
+Graphics output is available, but unlike the x86 PC machine types
+there is no default display device enabled: you should select one from
+the Display devices section of "-device help". The recommended option
+is ``virtio-gpu-pci``; this is the only one which will work correctly
+with KVM. You may also need to ensure your guest kernel is configured
+with support for this; see below.
+
+Machine-specific options
+""""""""""""""""""""""""
+
+The following machine-specific options are supported:
+
+secure
+  Set ``on``/``off`` to enable/disable emulating a guest CPU which implements the
+  Arm Security Extensions (TrustZone). The default is ``off``.
+
+virtualization
+  Set ``on``/``off`` to enable/disable emulating a guest CPU which implements the
+  Arm Virtualization Extensions. The default is ``off``.
+
+highmem
+  Set ``on``/``off`` to enable/disable placing devices and RAM in physical
+  address space above 32 bits. The default is ``on`` for machine types
+  later than ``virt-2.12``.
+
+gic-version
+  Specify the version of the Generic Interrupt Controller (GIC) to provide.
+  Valid values are:
+
+  ``2``
+    GICv2
+  ``3``
+    GICv3
+  ``host``
+    Use the same GIC version the host provides, when using KVM
+  ``max``
+    Use the best GIC version possible (same as host when using KVM;
+    currently same as ``3``` for TCG, but this may change in future)
+
+its
+  Set ``on``/``off`` to enable/disable ITS instantiation. The default is ``on``
+  for machine types later than ``virt-2.7``.
+
+iommu
+  Set the IOMMU type to create for the guest. Valid values are:
+
+  ``none``
+    Don't create an IOMMU (the default)
+  ``smmuv3``
+    Create an SMMUv3
+
+ras
+  Set ``on``/``off`` to enable/disable reporting host memory errors to a guest
+  using ACPI and guest external abort exceptions. The default is off.
+
+Linux guest kernel configuration
+""""""""""""""""""""""""""""""""
+
+The 'defconfig' for Linux arm and arm64 kernels should include the
+right device drivers for virtio and the PCI controller; however some older
+kernel versions, especially for 32-bit Arm, did not have everything
+enabled by default. If you're not seeing PCI devices that you expect,
+then check that your guest config has::
+
+  CONFIG_PCI=y
+  CONFIG_VIRTIO_PCI=y
+  CONFIG_PCI_HOST_GENERIC=y
+
+If you want to use the ``virtio-gpu-pci`` graphics device you will also
+need::
+
+  CONFIG_DRM=y
+  CONFIG_DRM_VIRTIO_GPU=y
+
+Hardware configuration information for bare-metal programming
+"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+The ``virt`` board automatically generates a device tree blob ("dtb")
+which it passes to the guest. This provides information about the
+addresses, interrupt lines and other configuration of the various devices
+in the system. Guest code can rely on and hard-code the following
+addresses:
+
+- Flash memory starts at address 0x0000_0000
+
+- RAM starts at 0x4000_0000
+
+All other information about device locations may change between
+QEMU versions, so guest code must look in the DTB.
+
+QEMU supports two types of guest image boot for ``virt``, and
+the way for the guest code to locate the dtb binary differs:
+
+- For guests using the Linux kernel boot protocol (this means any
+  non-ELF file passed to the QEMU ``-kernel`` option) the address
+  of the DTB is passed in a register (``r2`` for 32-bit guests,
+  or ``x0`` for 64-bit guests)
+
+- For guests booting as "bare-metal" (any other kind of boot),
+  the DTB is at the start of RAM (0x4000_0000)
diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
index 163ab915592..4c5b0e4aab8 100644
--- a/docs/system/target-arm.rst
+++ b/docs/system/target-arm.rst
@@ -92,6 +92,7 @@ undocumented; you can get a complete list by running
    arm/collie
    arm/sx1
    arm/stellaris
+   arm/virt
 
 Arm CPU features
 ================
diff --git a/MAINTAINERS b/MAINTAINERS
index 286b076da89..553760e5442 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -878,6 +878,7 @@ L: qemu-arm@nongnu.org
 S: Maintained
 F: hw/arm/virt*
 F: include/hw/arm/virt.h
+F: docs/system/arm/virt.rst
 
 Xilinx Zynq
 M: Edgar E. Iglesias <edgar.iglesias@gmail.com>
-- 
2.20.1

Re: [PATCH for-5.1 4/4] docs/system: Document the arm virt board

[Alex Bennée]

Peter Maydell <peter.maydell@linaro.org> writes:

> Document the arm 'virt' board, which has been undocumented
> for far too long given that it is the main recommended board
> type for arm guests.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  docs/system/arm/virt.rst   | 157 +++++++++++++++++++++++++++++++++++++
>  docs/system/target-arm.rst |   1 +
>  MAINTAINERS                |   1 +
>  3 files changed, 159 insertions(+)
>  create mode 100644 docs/system/arm/virt.rst
>
> diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst
> new file mode 100644
> index 00000000000..6a7823d8bca
> --- /dev/null
> +++ b/docs/system/arm/virt.rst
> @@ -0,0 +1,157 @@
> +'virt' generic virtual platform (``virt``)
> +==========================================
> +
> +The `virt` board is a platform which does not correspond to any
> +real hardware; it is designed for use in virtual machines.
> +It is the recommended board type if you simply want to run
> +a guest such as Linux and do not care about reproducing the
> +idiosyncrasies and limitations of a particular bit of real-world
> +hardware.
> +
> +This is a "versioned" board model, so as well as the ``virt`` machine
> +type itself (which may have improvements, bugfixes and other minor
> +changes between QEMU versions) a version is provided that guarantees
> +to have the same behaviour as that of previous QEMU releases, so
> +that VM migration will work between QEMU versions. For instance the
> +``virt-5.0`` machine type will behave like the ``virt`` machine from
> +the QEMU 5.0 release, and migration should work between ``virt-5.0``
> +of the 5.0 release and ``virt-5.0`` of the 5.1 release. Migration
> +is not guaranteed to work between different QEMU releases for
> +the non-versioned ``virt`` machine type.
> +
> +Supported devices
> +"""""""""""""""""
> +
> +The virt board supports:
> +
> +- Flash memory
> +- One PL011 UART
> +- An RTC
> +- The fw_cfg device that allows a guest to obtain data from QEMU
> +- A PL061 GPIO controller
> +- An optional SMMUv3 IOMMU
> +- hotpluggable DIMMs
> +- hotpluggable NVDIMs
> +- 32 virtio-mmio transport devices

We seem to miss out we also support the virtio-pci transports here.

Otherwise:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>


-- 
Alex Bennée

Re: [PATCH for-5.1 4/4] docs/system: Document the arm virt board

[Peter Maydell]

On Tue, 14 Jul 2020 at 15:58, Alex Bennée <alex.bennee@linaro.org> wrote:
>
>
> Peter Maydell <peter.maydell@linaro.org> writes:
>
> > Document the arm 'virt' board, which has been undocumented
> > for far too long given that it is the main recommended board
> > type for arm guests.
> >
> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> > ---
> >  docs/system/arm/virt.rst   | 157 +++++++++++++++++++++++++++++++++++++
> >  docs/system/target-arm.rst |   1 +
> >  MAINTAINERS                |   1 +
> >  3 files changed, 159 insertions(+)
> >  create mode 100644 docs/system/arm/virt.rst
> >
> > diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst
> > new file mode 100644
> > index 00000000000..6a7823d8bca
> > --- /dev/null
> > +++ b/docs/system/arm/virt.rst
> > @@ -0,0 +1,157 @@
> > +'virt' generic virtual platform (``virt``)
> > +==========================================
> > +
> > +The `virt` board is a platform which does not correspond to any
> > +real hardware; it is designed for use in virtual machines.
> > +It is the recommended board type if you simply want to run
> > +a guest such as Linux and do not care about reproducing the
> > +idiosyncrasies and limitations of a particular bit of real-world
> > +hardware.
> > +
> > +This is a "versioned" board model, so as well as the ``virt`` machine
> > +type itself (which may have improvements, bugfixes and other minor
> > +changes between QEMU versions) a version is provided that guarantees
> > +to have the same behaviour as that of previous QEMU releases, so
> > +that VM migration will work between QEMU versions. For instance the
> > +``virt-5.0`` machine type will behave like the ``virt`` machine from
> > +the QEMU 5.0 release, and migration should work between ``virt-5.0``
> > +of the 5.0 release and ``virt-5.0`` of the 5.1 release. Migration
> > +is not guaranteed to work between different QEMU releases for
> > +the non-versioned ``virt`` machine type.
> > +
> > +Supported devices
> > +"""""""""""""""""
> > +
> > +The virt board supports:
> > +
> > +- Flash memory
> > +- One PL011 UART
> > +- An RTC
> > +- The fw_cfg device that allows a guest to obtain data from QEMU
> > +- A PL061 GPIO controller
> > +- An optional SMMUv3 IOMMU
> > +- hotpluggable DIMMs
> > +- hotpluggable NVDIMs
> > +- 32 virtio-mmio transport devices
>
> We seem to miss out we also support the virtio-pci transports here.

That's just a special case of "PCI", which I did indeed somehow forget.

 + PCI devices

thanks
-- PMM

Re: [PATCH for-5.1 4/4] docs/system: Document the arm virt board

[Auger Eric]

Hi Peter,
On 7/13/20 7:57 PM, Peter Maydell wrote:
> Document the arm 'virt' board, which has been undocumented
> for far too long given that it is the main recommended board
> type for arm guests.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  docs/system/arm/virt.rst   | 157 +++++++++++++++++++++++++++++++++++++
>  docs/system/target-arm.rst |   1 +
>  MAINTAINERS                |   1 +
>  3 files changed, 159 insertions(+)
>  create mode 100644 docs/system/arm/virt.rst
> 
> diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst
> new file mode 100644
> index 00000000000..6a7823d8bca
> --- /dev/null
> +++ b/docs/system/arm/virt.rst
> @@ -0,0 +1,157 @@
> +'virt' generic virtual platform (``virt``)
> +==========================================
> +
> +The `virt` board is a platform which does not correspond to any
> +real hardware; it is designed for use in virtual machines.
> +It is the recommended board type if you simply want to run
> +a guest such as Linux and do not care about reproducing the
> +idiosyncrasies and limitations of a particular bit of real-world
> +hardware.
> +
> +This is a "versioned" board model, so as well as the ``virt`` machine
> +type itself (which may have improvements, bugfixes and other minor
> +changes between QEMU versions) a version is provided that guarantees
> +to have the same behaviour as that of previous QEMU releases, so
> +that VM migration will work between QEMU versions.

Note: as per the recent discussions, the ACPI description is currently
allowed to changed and this is not really versionned. Normally this
should not really impact the guest but who knows?
 For instance the
> +``virt-5.0`` machine type will behave like the ``virt`` machine from
> +the QEMU 5.0 release, and migration should work between ``virt-5.0``
> +of the 5.0 release and ``virt-5.0`` of the 5.1 release. Migration
> +is not guaranteed to work between different QEMU releases for
> +the non-versioned ``virt`` machine type.
> +
> +Supported devices
> +"""""""""""""""""
> +
> +The virt board supports:
> +
> +- Flash memory
> +- One PL011 UART
> +- An RTC
> +- The fw_cfg device that allows a guest to obtain data from QEMU
> +- A PL061 GPIO controller
> +- An optional SMMUv3 IOMMU
> +- hotpluggable DIMMs
> +- hotpluggable NVDIMs
NVDIMMs
- an MSI controller (GICv2M or ITS). GICv2M is selected by default along
with GICv2. ITS is selected by default with GICv3 (>= virt-2.7). Note
ITS is not modeled in TCG mode.
> +- 32 virtio-mmio transport devices
> +- running guests using the KVM accelerator on aarch64 hardware
> +- large amounts of RAM (at least 255GB, and more if using highmem)
> +- many CPUs (up to 512 if using a GICv3 and highmem)
> +- Secure-World-only devices if the CPU has TrustZone:
> +
> +  - A second PL011 UART
> +  - A secure flash memory
> +  - 16MB of secure RAM
> +
> +Supported guest CPU types:
> +
> +- ``cortex-a7`` (32-bit)
> +- ``cortex-a15`` (32-bit; the default)
> +- ``cortex-a53`` (64-bit)
> +- ``cortex-a57`` (64-bit)
> +- ``cortex-a72`` (64-bit)
> +- ``host`` (with KVM only)
> +- ``max`` (same as ``host`` for KVM; best possible emulation with TCG)
> +
> +Note that the default is ``cortex-a15``, so for an AArch64 guest you must
> +specify a CPU type.
> +
> +Graphics output is available, but unlike the x86 PC machine types
> +there is no default display device enabled: you should select one from
> +the Display devices section of "-device help". The recommended option
> +is ``virtio-gpu-pci``; this is the only one which will work correctly
> +with KVM. You may also need to ensure your guest kernel is configured
> +with support for this; see below.
> +
> +Machine-specific options
> +""""""""""""""""""""""""
> +
> +The following machine-specific options are supported:
> +
> +secure
> +  Set ``on``/``off`` to enable/disable emulating a guest CPU which implements the
> +  Arm Security Extensions (TrustZone). The default is ``off``.
> +
> +virtualization
> +  Set ``on``/``off`` to enable/disable emulating a guest CPU which implements the
> +  Arm Virtualization Extensions. The default is ``off``.
> +
> +highmem
> +  Set ``on``/``off`` to enable/disable placing devices and RAM in physical
> +  address space above 32 bits. The default is ``on`` for machine types
> +  later than ``virt-2.12``.
> +
> +gic-version
> +  Specify the version of the Generic Interrupt Controller (GIC) to provide.
> +  Valid values are:
> +
> +  ``2``
> +    GICv2
> +  ``3``
> +    GICv3
> +  ``host``
> +    Use the same GIC version the host provides, when using KVM
> +  ``max``
> +    Use the best GIC version possible (same as host when using KVM;
> +    currently same as ``3``` for TCG, but this may change in future)
> +
> +its
> +  Set ``on``/``off`` to enable/disable ITS instantiation. The default is ``on``
> +  for machine types later than ``virt-2.7``.
> +
> +iommu
> +  Set the IOMMU type to create for the guest. Valid values are:
> +
> +  ``none``
> +    Don't create an IOMMU (the default)
> +  ``smmuv3``
> +    Create an SMMUv3
> +
> +ras
> +  Set ``on``/``off`` to enable/disable reporting host memory errors to a guest
> +  using ACPI and guest external abort exceptions. The default is off.> +
> +Linux guest kernel configuration
> +""""""""""""""""""""""""""""""""
> +
> +The 'defconfig' for Linux arm and arm64 kernels should include the
> +right device drivers for virtio and the PCI controller; however some older
> +kernel versions, especially for 32-bit Arm, did not have everything
> +enabled by default. If you're not seeing PCI devices that you expect,
> +then check that your guest config has::
> +
> +  CONFIG_PCI=y
> +  CONFIG_VIRTIO_PCI=y
> +  CONFIG_PCI_HOST_GENERIC=y
> +
> +If you want to use the ``virtio-gpu-pci`` graphics device you will also
> +need::
> +
> +  CONFIG_DRM=y
> +  CONFIG_DRM_VIRTIO_GPU=y
> +
> +Hardware configuration information for bare-metal programming
> +"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
> +
> +The ``virt`` board automatically generates a device tree blob ("dtb")
> +which it passes to the guest. This provides information about the
> +addresses, interrupt lines and other configuration of the various devices
> +in the system. Guest code can rely on and hard-code the following
> +addresses:
> +
> +- Flash memory starts at address 0x0000_0000
> +
> +- RAM starts at 0x4000_0000
> +
> +All other information about device locations may change between
> +QEMU versions, so guest code must look in the DTB.
> +
> +QEMU supports two types of guest image boot for ``virt``, and
> +the way for the guest code to locate the dtb binary differs:
> +
> +- For guests using the Linux kernel boot protocol (this means any
> +  non-ELF file passed to the QEMU ``-kernel`` option) the address
> +  of the DTB is passed in a register (``r2`` for 32-bit guests,
> +  or ``x0`` for 64-bit guests)
> +
> +- For guests booting as "bare-metal" (any other kind of boot),
> +  the DTB is at the start of RAM (0x4000_0000)
> diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
> index 163ab915592..4c5b0e4aab8 100644
> --- a/docs/system/target-arm.rst
> +++ b/docs/system/target-arm.rst
> @@ -92,6 +92,7 @@ undocumented; you can get a complete list by running
>     arm/collie
>     arm/sx1
>     arm/stellaris
> +   arm/virt
>  
>  Arm CPU features
>  ================
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 286b076da89..553760e5442 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -878,6 +878,7 @@ L: qemu-arm@nongnu.org
>  S: Maintained
>  F: hw/arm/virt*
>  F: include/hw/arm/virt.h
> +F: docs/system/arm/virt.rst
>  
>  Xilinx Zynq
>  M: Edgar E. Iglesias <edgar.iglesias@gmail.com>
> 
Thanks

Eric

Re: [PATCH for-5.1 0/4] Document virt and a few other Arm boards

[Peter Maydell]

On Mon, 13 Jul 2020 at 18:57, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> This series adds some documentation to the system manual for
> previously undocumented Arm board types.

Applied to target-arm.next for 5.1 with the minor wording
tweaks/additions suggested by various reviewers -- thanks!

-- PMM