[Qemu-devel] [Bug 1685242] [NEW] ovmf hangs at efi with virtio-net memory hotplug

[Qemu-devel] [Bug 1685242] [NEW] ovmf hangs at efi with virtio-net memory hotplug

[flumm]

Public bug reported:

with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
and it has a virtio-net devices

the ovmf images where compiled from https://github.com/tianocore/edk2
(current master)

reproducer:

qemu-system-x86_64 -drive
'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
-netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
-display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

interestingly, it works when you do the following:

- omit the virtio-net-pci device
- use seabios
- use less maxmem, e.g. 512G

qemu was compiled from source (v2.9.0) with following options:

./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
-spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

** Affects: qemu
     Importance: Undecided
         Status: New

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[flumm]

i forgot:

it also works with

-machine pc-i440fx-2.6

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[ITEAS]

Tested here with versions of pc-i440fx-XX and it didn't work here on
qemu-server 5.0-46, qemu 2.12.1-1

Didn't work.

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[Laszlo Ersek (Red Hat)]

OVMF places the 64-bit PCI MMIO aperture after the memory hotplug area.
If you specify `-m maxmem=1024G`, then accessing 64-bit MMIO BARs of
PCI(e) devices, allocated from the aperture, will require at least 41
address bits. If you use KVM, and nested paging (EPT on Intel, NPT on
AMD) is enabled, and your /proc/cpuinfo on the host reports a smaller
phys address width than 41, then 64-bit PCI MMIO accesses in the guest
will silently fail. You can read more details in
<https://bugzilla.redhat.com/show_bug.cgi?id=1353591#c8>.

SeaBIOS uses an independent algorithm for aperture placement and BAR
allocation.

If you remove virtio-net-pci, then your command line ends up without any
PCI(e) device that has a 64-bit MMIO BAR. So the issue is not triggered.

If you use a maxmem of 512G, then 40 bits might suffice. It's possible
that your physical CPU has precisely that many address bits, and so the
behavior could change.

If you attach the OVMF debug log (capture `-debugcon file:debug.log
-global isa-debugcon.iobase=0x402`), I could say more.

Thus far this ticket looks like "NOTABUG" -- use a smaller memory
hotplug area, or disable nested paging (which will come with a
performance penalty).

** Bug watch added: Red Hat Bugzilla #1353591
   https://bugzilla.redhat.com/show_bug.cgi?id=1353591

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[flumm]

i see,

but is there a good reason why it did work with an older qemu version/machine type (<= 2.6)
also my cpuinfo says physical bits 39 but i cannot use more maxmem than 222G

i attached the cpuinfo, cmdline, and debug logs for a nonworking invocation and
one for each working, with 222G, with machine type 2.6 and without a virtio-net respectively


** Attachment added: "/proc/cpuinfo"
   https://bugs.launchpad.net/qemu/+bug/1685242/+attachment/5240131/+files/cpuinfo

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[flumm]

** Attachment added: "qemu-cmdline"
   https://bugs.launchpad.net/qemu/+bug/1685242/+attachment/5240133/+files/qemu-cmdline

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[flumm]

** Attachment added: "qemu-cmdline"
   https://bugs.launchpad.net/qemu/+bug/1685242/+attachment/5240132/+files/qemu-cmdline

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[flumm]

** Attachment added: "debug-nonworking.log"
   https://bugs.launchpad.net/qemu/+bug/1685242/+attachment/5240134/+files/debug-nonworking.log

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[flumm]

** Attachment added: "debug-working-222G.log"
   https://bugs.launchpad.net/qemu/+bug/1685242/+attachment/5240135/+files/debug-working-222G.log

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[flumm]

** Attachment added: "debug-working-2.6.log"
   https://bugs.launchpad.net/qemu/+bug/1685242/+attachment/5240136/+files/debug-working-2.6.log

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[flumm]

** Attachment added: "debug-working-novirtio-net.log"
   https://bugs.launchpad.net/qemu/+bug/1685242/+attachment/5240137/+files/debug-working-novirtio-net.log

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Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[Laszlo Ersek (Red Hat)]

The reason why it behaves differently with machine types <= 2.4 is that
- up to and including qemu-2.4, the calculation of the DIMM hotplug area was incorrect,
- in 2.5, the calculation was fixed,
- but for the migration compatibility of machine types <= 2.4, the old calculation was preserved for those machine types (the DIMM hotplug area is guest-visible)

See the following (adjacent) commits:
- 3385e8e2640e ("pc: memhotplug: fix incorrectly set reserved-memory-end", 2015-09-10)
- 2f8b50083b32 ("pc: memhotplug: keep reserved-memory-end broken on 2.4 and earlier machines", 2015-09-10)

These commits were first released in v2.5.0.

I'll look at your logs now.

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https://bugs.launchpad.net/bugs/1685242

Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  New

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[Laszlo Ersek (Red Hat)]

* From "debug-nonworking.log":

> GetFirstNonAddress: Pci64Base=0x8800000000 Pci64Size=0x800000000
> [...]
> PublishPeiMemory: mPhysMemAddressWidth=40 PeiMemoryCap=69644 KB
> [...]
> Type =  Mem64; Base = 0x8800000000;	Length = 0x100000;	Alignment = 0xFFFFF
>  Base = 0x8800000000;	Length = 0x4000;	Alignment = 0x3FFF;	Owner = PCI [00|12|00:20]; Type = PMem64

- The 64-bit MMIO aperture starts at (512+32)GB (see "Pci64Base").
- 40 physical address bits are required (see "mPhysMemAddressWidth").
  Your PCPU has 39 (thanks for confirming that).
- The 64-bit MMIO BAR of the virtio-net-pci device is allocated at
  (512+32)GB. Will not be accessible.


* From "debug-working-222G.log":

> GetFirstNonAddress: Pci64Base=0x7800000000 Pci64Size=0x800000000
> [...]
> PublishPeiMemory: mPhysMemAddressWidth=39 PeiMemoryCap=67592 KB
> [...]
> Type =  Mem64; Base = 0x7800000000;	Length = 0x100000;	Alignment = 0xFFFFF
>  Base = 0x7800000000;	Length = 0x4000;	Alignment = 0x3FFF;	Owner = PCI [00|12|00:20]; Type = PMem64

- Aperture at 480GB.
- 39 phys bits suffice.
- BAR allocated at 480GB. Will be accessible.


* From "debug-working-novirtio-net.log":

- Identical to "debug-nonworking.log", except there is no PCI device
  with a 64-bit BAR, hence no attempt is made to access the inaccessible
  aperture.


* Regarding why 222GB seems to be the cutoff. The base of the 64-bit
  aperture must be suitably aligned. I explained this in the
  earlier-referenced
  <https://bugzilla.redhat.com/show_bug.cgi?id=1353591#c8>, in
  particular, bullet (6). If you decrease the aperture size, the
  required alignment will shrink as well, and the DIMM hotplug cutoff
  might increase. Please refer to

    -fw_cfg name=opt/ovmf/X-PciMmio64Mb,string=4096

  in <https://bugzilla.redhat.com/show_bug.cgi?id=1353591#c10>.

Right now everything appears to work by design. Closing this ticket.


** Changed in: qemu
       Status: New => Invalid

-- 
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1685242

Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  Invalid

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

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[Qemu-devel] [Bug 1685242] Re: ovmf hangs at efi with virtio-net memory hotplug

[Laszlo Ersek (Red Hat)]

Last night I remembered another tidbit:

In OVMF, you can entirely disable the 64-bit MMIO aperture.

  -fw_cfg name=opt/ovmf/X-PciMmio64Mb,string=0

If you use the above switch, the firmware log should contain the
following message:

> GetFirstNonAddress: disabling 64-bit PCI host aperture

This will force the BAR allocations into 32-bit address space.
Obviously, that makes it a lot easier to run out of the (much smaller)
32-bit MMIO aperture, but if you don't have PCI(E) devices with large
MMIO BARs, then it should work (e.g. it should totally work in your
present use case).

And then you should be able to increase the DIMM hotplug area
significantly, without running out of the GPA range covered by 39
physical address bits:

    //
    // There's nothing more to do; the amount of memory above 4GB fully
    // determines the highest address plus one. The memory hotplug area (see
    // below) plays no role for the firmware in this case.
    //

"This case" beeing (Pci64Size == 0).

Hope this helps.

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1685242

Title:
  ovmf hangs at efi with virtio-net memory hotplug

Status in QEMU:
  Invalid

Bug description:
  with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled
  and it has a virtio-net devices

  the ovmf images where compiled from https://github.com/tianocore/edk2
  (current master)

  reproducer:

  qemu-system-x86_64 -drive
  'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive
  'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std
  -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet'
  -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

  interestingly, it works when you do the following:

  - omit the virtio-net-pci device
  - use seabios
  - use less maxmem, e.g. 512G

  qemu was compiled from source (v2.9.0) with following options:

  ./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
  -spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi

To manage notifications about this bug go to:
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