[Qemu-commits] [qemu/qemu] c22aba: virtio-mem-pci: force virtio version 1

[Peter Maydell]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: c22aba196341995f2e45c37eed36cc7be09e4bc3
      
https://github.com/qemu/qemu/commit/c22aba196341995f2e45c37eed36cc7be09e4bc3
  Author: David Hildenbrand <david@redhat.com>
  Date:   2020-07-27 (Mon, 27 Jul 2020)

  Changed paths:
    M hw/virtio/virtio-mem-pci.c

  Log Message:
  -----------
  virtio-mem-pci: force virtio version 1

Trying to run simple virtio-mem-pci examples currently fails with
    qemu-system-x86_64: -device virtio-mem-pci,id=vm0,memdev=mem0,node=0,
    requested-size=300M: device is modern-only, use disable-legacy=on
due to the added safety checks in 9b3a35ec8236 ("virtio: verify that legacy
support is not accidentally on").

As noted by Conny, we have to force virtio version 1. While at it, use
qdev_realize() to set the parent bus and realize - like most other
virtio-*-pci implementations.

Fixes: 0b9a2443a48b ("virtio-pci: Proxy for virtio-mem")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200727115905.129397-1-david@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>


  Commit: 2ebc21216f58f6fcbf16f7ec0bebe7f72ab3d8ca
      
https://github.com/qemu/qemu/commit/2ebc21216f58f6fcbf16f7ec0bebe7f72ab3d8ca
  Author: Hogan Wang <king.wang@huawei.com>
  Date:   2020-07-27 (Mon, 27 Jul 2020)

  Changed paths:
    M hw/core/machine.c
    M hw/i386/pc.c
    M hw/pci/pci_host.c
    M include/hw/pci/pci_host.h

  Log Message:
  -----------
  hw/pci-host: save/restore pci host config register

The pci host config register is used to save PCI address for
read/write config data. If guest writes a value to config register,
and then QEMU pauses the vcpu to migrate, after the migration, the guest
will continue to write pci config data, and the write data will be ignored
because of new qemu process losing the config register state.

To trigger the bug:
1. guest is booting in seabios.
2. guest enables the SMRAM in seabios:piix4_apmc_smm_setup, and then
   expects to disable the SMRAM by pci_config_writeb.
3. after guest writes the pci host config register, QEMU pauses vcpu
   to finish migration.
4. guest write of config data(0x0A) fails to disable the SMRAM because
   the config register state is lost.
5. guest continues to boot and crashes in ipxe option ROM due to SMRAM
   in enabled state.

Example Reproducer:

step 1. Make modifications to seabios and qemu for increase reproduction
efficiency, write 0xf0 to 0x402 port notify qemu to stop vcpu after
0x0cf8 port wrote i440 configure register. qemu stop vcpu when catch
0x402 port wrote 0xf0.

seabios:/src/hw/pci.c
@@ -52,6 +52,11 @@ void pci_config_writeb(u16 bdf, u32 addr, u8 val)
         writeb(mmconfig_addr(bdf, addr), val);
     } else {
         outl(ioconfig_cmd(bdf, addr), PORT_PCI_CMD);
+       if (bdf == 0 && addr == 0x72 && val == 0xa) {
+            dprintf(1, "stop vcpu\n");
+            outb(0xf0, 0x402); // notify qemu to stop vcpu
+            dprintf(1, "resume vcpu\n");
+        }
         outb(val, PORT_PCI_DATA + (addr & 3));
     }
 }

qemu:hw/char/debugcon.c
@@ -60,6 +61,9 @@ static void debugcon_ioport_write(void *opaque, hwaddr addr, 
uint64_t val,
     printf(" [debugcon: write addr=0x%04" HWADDR_PRIx " val=0x%02" PRIx64 
"]\n", addr, val);
 #endif

+    if (ch == 0xf0) {
+        vm_stop(RUN_STATE_PAUSED);
+    }
     /* XXX this blocks entire thread. Rewrite to use
      * qemu_chr_fe_write and background I/O callbacks */
     qemu_chr_fe_write_all(&s->chr, &ch, 1);

step 2. start vm1 by the following command line, and then vm stopped.
$ qemu-system-x86_64 -machine pc-i440fx-5.0,accel=kvm\
 -netdev tap,ifname=tap-test,id=hostnet0,vhost=on,downscript=no,script=no\
 -device virtio-net-pci,netdev=hostnet0,id=net0,bus=pci.0,addr=0x13,bootindex=3\
 -device cirrus-vga,id=video0,vgamem_mb=16,bus=pci.0,addr=0x2\
 -chardev file,id=seabios,path=/var/log/test.seabios,append=on\
 -device isa-debugcon,iobase=0x402,chardev=seabios\
 -monitor stdio

step 3. start vm2 to accept vm1 state.
$ qemu-system-x86_64 -machine pc-i440fx-5.0,accel=kvm\
 -netdev tap,ifname=tap-test1,id=hostnet0,vhost=on,downscript=no,script=no\
 -device virtio-net-pci,netdev=hostnet0,id=net0,bus=pci.0,addr=0x13,bootindex=3\
 -device cirrus-vga,id=video0,vgamem_mb=16,bus=pci.0,addr=0x2\
 -chardev file,id=seabios,path=/var/log/test.seabios,append=on\
 -device isa-debugcon,iobase=0x402,chardev=seabios\
 -monitor stdio \
 -incoming tcp:127.0.0.1:8000

step 4. execute the following qmp command in vm1 to migrate.
(qemu) migrate tcp:127.0.0.1:8000

step 5. execute the following qmp command in vm2 to resume vcpu.
(qemu) cont
Before this patch, we get KVM "emulation failure" error on vm2.
This patch fixes it.

Cc: qemu-stable@nongnu.org
Signed-off-by: Hogan Wang <hogan.wang@huawei.com>
Message-Id: <20200727084621.3279-1-hogan.wang@huawei.com>
Reported-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>


  Commit: 4fdecf0543b49b8e171510104f3117538b9d1fe9
      
https://github.com/qemu/qemu/commit/4fdecf0543b49b8e171510104f3117538b9d1fe9
  Author: Raphael Norwitz <raphael.norwitz@nutanix.com>
  Date:   2020-07-27 (Mon, 27 Jul 2020)

  Changed paths:
    M hw/virtio/vhost-user.c

  Log Message:
  -----------
  Fix vhost-user buffer over-read on ram hot-unplug

The VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS vhost-user protocol
feature introduced a shadow-table, used by the backend to dynamically
determine how a vdev's memory regions have changed since the last
vhost_user_set_mem_table() call. On hot-remove, a memmove() operation
is used to overwrite the removed shadow region descriptor(s). The size
parameter of this memmove was off by 1 such that if a VM with a backend
supporting the VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS filled it's
shadow-table (by performing the maximum number of supported hot-add
operatons) and attempted to remove the last region, Qemu would read an
out of bounds value and potentially crash.

This change fixes the memmove() bounds such that this erroneous read can
never happen.

Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <1594799958-31356-1-git-send-email-raphael.norwitz@nutanix.com>
Fixes: f1aeb14b0809 ("Transmit vhost-user memory regions individually")
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>


  Commit: 8fe9805c73c277dc2feeaa83de73d6a58bf23f39
      
https://github.com/qemu/qemu/commit/8fe9805c73c277dc2feeaa83de73d6a58bf23f39
  Author: Philippe Mathieu-Daudé <philmd@redhat.com>
  Date:   2020-07-27 (Mon, 27 Jul 2020)

  Changed paths:
    M contrib/libvhost-user/libvhost-user.c

  Log Message:
  -----------
  libvhost-user: Report descriptor index on panic

We want to report the index of the descriptor,
not its pointer.

Fixes: 7b2e5c65f4 ("contrib: add libvhost-user")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200723171935.18535-1-philmd@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>


  Commit: 386494f29e2b902bc501176573bb4c69eab666c4
      
https://github.com/qemu/qemu/commit/386494f29e2b902bc501176573bb4c69eab666c4
  Author: Cindy Lu <lulu@redhat.com>
  Date:   2020-07-27 (Mon, 27 Jul 2020)

  Changed paths:
    M hw/virtio/vhost-vdpa.c

  Log Message:
  -----------
  vhost-vdpa :Fix Coverity CID 1430270 / CID 1420267

In the function vhost_vdpa_dma_map/unmap, The struct msg was not initialized 
all its fields.

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20200710064642.24505-1-lulu@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>


  Commit: d0d89526f70ded5ac41a4c6bb071c0d919b772db
      
https://github.com/qemu/qemu/commit/d0d89526f70ded5ac41a4c6bb071c0d919b772db
  Author: Philippe Mathieu-Daudé <philmd@redhat.com>
  Date:   2020-07-27 (Mon, 27 Jul 2020)

  Changed paths:
    M MAINTAINERS

  Log Message:
  -----------
  MAINTAINERS: Cover the firmware JSON schema

Add an entry to cover firmware.json (see commit 3a0adfc9bf:
schema that describes the different uses and properties of
virtual machine firmware).

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Kashyap Chamarthy <kchamart@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200703183450.32398-1-philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>


  Commit: 0c9753ebda274b0e618d7b4032bb2d83d27483ed
      
https://github.com/qemu/qemu/commit/0c9753ebda274b0e618d7b4032bb2d83d27483ed
  Author: Laurent Vivier <lvivier@redhat.com>
  Date:   2020-07-27 (Mon, 27 Jul 2020)

  Changed paths:
    M hw/virtio/virtio-pci.c
    M hw/virtio/virtio.c
    M include/hw/virtio/virtio.h

  Log Message:
  -----------
  virtio-pci: fix virtio_pci_queue_enabled()

In legacy mode, virtio_pci_queue_enabled() falls back to
virtio_queue_enabled() to know if the queue is enabled.

But virtio_queue_enabled() calls again virtio_pci_queue_enabled()
if k->queue_enabled is set. This ends in a crash after a stack
overflow.

The problem can be reproduced with
"-device virtio-net-pci,disable-legacy=off,disable-modern=true
 -net tap,vhost=on"

And a look to the backtrace is very explicit:

    ...
    #4  0x000000010029a438 in virtio_queue_enabled ()
    #5  0x0000000100497a9c in virtio_pci_queue_enabled ()
    ...
    #130902 0x000000010029a460 in virtio_queue_enabled ()
    #130903 0x0000000100497a9c in virtio_pci_queue_enabled ()
    #130904 0x000000010029a460 in virtio_queue_enabled ()
    #130905 0x0000000100454a20 in vhost_net_start ()
    ...

This patch fixes the problem by introducing a new function
for the legacy case and calls it from virtio_pci_queue_enabled().
It also calls it from virtio_queue_enabled() to avoid code duplication.

Fixes: f19bcdfedd53 ("virtio-pci: implement queue_enabled method")
Cc: Jason Wang <jasowang@redhat.com>
Cc: Cindy Lu <lulu@redhat.com>
CC: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20200727153319.43716-1-lvivier@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>


  Commit: 93ea484375ab473379dd9c836261ef484bd71ab1
      
https://github.com/qemu/qemu/commit/93ea484375ab473379dd9c836261ef484bd71ab1
  Author: Peter Maydell <peter.maydell@linaro.org>
  Date:   2020-07-27 (Mon, 27 Jul 2020)

  Changed paths:
    M MAINTAINERS
    M contrib/libvhost-user/libvhost-user.c
    M hw/core/machine.c
    M hw/i386/pc.c
    M hw/pci/pci_host.c
    M hw/virtio/vhost-user.c
    M hw/virtio/vhost-vdpa.c
    M hw/virtio/virtio-mem-pci.c
    M hw/virtio/virtio-pci.c
    M hw/virtio/virtio.c
    M include/hw/pci/pci_host.h
    M include/hw/virtio/virtio.h

  Log Message:
  -----------
  Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

virtio,pci: bugfixes

Minor bugfixes all over the places, including one CVE.

Additionally, a fix for an ancient bug in migration -
one has to wonder how come no one noticed.

The fix is also non-trivial since we dare not break all
existing machine types with pci - we have a work around
in the works, for now we just skip the work-around for
old machine types.

Great job by Hogan Wang noticing, debugging and fixing it,
and thanks to Dr. David Alan Gilbert for reviewing the patches.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Mon 27 Jul 2020 16:34:58 BST
# gpg:                using RSA key 5D09FD0871C8F85B94CA8A0D281F0DB8D28D5469
# gpg:                issuer "mst@redhat.com"
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>" [full]
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>" [full]
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream:
  virtio-pci: fix virtio_pci_queue_enabled()
  MAINTAINERS: Cover the firmware JSON schema
  vhost-vdpa :Fix Coverity CID 1430270 / CID 1420267
  libvhost-user: Report descriptor index on panic
  Fix vhost-user buffer over-read on ram hot-unplug
  hw/pci-host: save/restore pci host config register
  virtio-mem-pci: force virtio version 1

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>


Compare: https://github.com/qemu/qemu/compare/9303ecb658a0...93ea484375ab