| Message ID | 20240410161203.437079-1-lulu@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] virtio-pci: Fix the crash that the vector was used after released. | expand |
On Thu, Apr 11, 2024 at 12:12:00AM +0800, Cindy Lu wrote: > During the booting process of the non-standard image, the behavior of the > called function in qemu is as follows: > > 1. vhost_net_stop() was triggered by guest image. This will call the function > virtio_pci_set_guest_notifiers() with assgin= false, > virtio_pci_set_guest_notifiers(） will release the irqfd for vector 0 > > 2. virtio_reset() was triggered, this will set configure vector to VIRTIO_NO_VECTOR > > 3.vhost_net_start() was called (at this time, the configure vector is > still VIRTIO_NO_VECTOR) and then call virtio_pci_set_guest_notifiers() with > assgin=true, so the irqfd for vector 0 is still not "init" during this process > > 4. The system continues to boot and sets the vector back to 0. After that > msix_fire_vector_notifier() was triggered to unmask the vector 0 and meet the crash > > To fix the issue, we need to support changing the vector after VIRTIO_CONFIG_S_DRIVER_OK is set. > > (gdb) bt > 0 __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) > at pthread_kill.c:44 > 1 0x00007fc87148ec53 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78 > 2 0x00007fc87143e956 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26 > 3 0x00007fc8714287f4 in __GI_abort () at abort.c:79 > 4 0x00007fc87142871b in __assert_fail_base > (fmt=0x7fc8715bbde0 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x5606413efd53 "ret == 0", file=0x5606413ef87d "../accel/kvm/kvm-all.c", line=1837, function=<optimized out>) at assert.c:92 > 5 0x00007fc871437536 in __GI___assert_fail > (assertion=0x5606413efd53 "ret == 0", file=0x5606413ef87d "../accel/kvm/kvm-all.c", line=1837, function=0x5606413f06f0 <__PRETTY_FUNCTION__.19> "kvm_irqchip_commit_routes") at assert.c:101 > 6 0x0000560640f884b5 in kvm_irqchip_commit_routes (s=0x560642cae1f0) at ../accel/kvm/kvm-all.c:1837 > 7 0x0000560640c98f8e in virtio_pci_one_vector_unmask > (proxy=0x560643c65f00, queue_no=4294967295, vector=0, msg=..., n=0x560643c6e4c8) > at ../hw/virtio/virtio-pci.c:1005 > 8 0x0000560640c99201 in virtio_pci_vector_unmask (dev=0x560643c65f00, vector=0, msg=...) > at ../hw/virtio/virtio-pci.c:1070 > 9 0x0000560640bc402e in msix_fire_vector_notifier (dev=0x560643c65f00, vector=0, is_masked=false) > at ../hw/pci/msix.c:120 > 10 0x0000560640bc40f1 in msix_handle_mask_update (dev=0x560643c65f00, vector=0, was_masked=true) > at ../hw/pci/msix.c:140 > 11 0x0000560640bc4503 in msix_table_mmio_write (opaque=0x560643c65f00, addr=12, val=0, size=4) > at ../hw/pci/msix.c:231 > 12 0x0000560640f26d83 in memory_region_write_accessor > (mr=0x560643c66540, addr=12, value=0x7fc86b7bc628, size=4, shift=0, mask=4294967295, attrs=...) > at ../system/memory.c:497 > 13 0x0000560640f270a6 in access_with_adjusted_size > > (addr=12, value=0x7fc86b7bc628, size=4, access_size_min=1, access_size_max=4, access_fn=0x560640f26c8d <memory_region_write_accessor>, mr=0x560643c66540, attrs=...) at ../system/memory.c:573 > 14 0x0000560640f2a2b5 in memory_region_dispatch_write (mr=0x560643c66540, addr=12, data=0, op=MO_32, attrs=...) > at ../system/memory.c:1521 > 15 0x0000560640f37bac in flatview_write_continue > (fv=0x7fc65805e0b0, addr=4273803276, attrs=..., ptr=0x7fc871e9c028, len=4, addr1=12, l=4, mr=0x560643c66540) > at ../system/physmem.c:2714 > 16 0x0000560640f37d0f in flatview_write > (fv=0x7fc65805e0b0, addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4) at ../system/physmem.c:2756 > 17 0x0000560640f380bf in address_space_write > (as=0x560642161ae0 <address_space_memory>, addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4) > at ../system/physmem.c:2863 > 18 0x0000560640f3812c in address_space_rw > (as=0x560642161ae0 <address_space_memory>, addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4, is_write=true) at ../system/physmem.c:2873 > --Type <RET> for more, q to quit, c to continue without paging-- > 19 0x0000560640f8aa55 in kvm_cpu_exec (cpu=0x560642f205e0) at ../accel/kvm/kvm-all.c:2915 > 20 0x0000560640f8d731 in kvm_vcpu_thread_fn (arg=0x560642f205e0) at ../accel/kvm/kvm-accel-ops.c:51 > 21 0x00005606411949f4 in qemu_thread_start (args=0x560642f292b0) at ../util/qemu-thread-posix.c:541 > 22 0x00007fc87148cdcd in start_thread (arg=<optimized out>) at pthread_create.c:442 > 23 0x00007fc871512630 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 > (gdb) > Signed-off-by: Cindy Lu <lulu@redhat.com> > --- > hw/virtio/virtio-pci.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 1a7039fb0c..b3b1a4a66f 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -1570,7 +1570,22 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr, > } else { > val = VIRTIO_NO_VECTOR; > } > + vector = vdev->config_vector; > vdev->config_vector = val; > + /* > + * If the value was changed after DRIVER_OK was set, it means that > + * we need to release the old vector and set up the new vector. > + */ > + if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && > + /*check if use the irqfd*/ > + (msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled())) { > + if (val != VIRTIO_NO_VECTOR) { > + kvm_virtio_pci_vector_use_one(proxy, VIRTIO_CONFIG_IRQ_IDX); > + } > + if (vector != VIRTIO_NO_VECTOR) { > + kvm_virtio_pci_vector_release_one(proxy, VIRTIO_CONFIG_IRQ_IDX); > + } > + } > break; > case VIRTIO_PCI_COMMON_STATUS: > if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) { > @@ -1611,6 +1626,21 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr, > val = VIRTIO_NO_VECTOR; > } > virtio_queue_set_vector(vdev, vdev->queue_sel, val); > + > + /* > + * If the value was changed after DRIVER_OK was set, it means that > + * we need to release the old vector and set up the new vector. > + */ > + if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && > + /*check if use the irqfd*/ by comment style > + (msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled())) { > + if (val != VIRTIO_NO_VECTOR) { > + kvm_virtio_pci_vector_use_one(proxy, vdev->queue_sel); > + } > + if (vector != VIRTIO_NO_VECTOR) { > + kvm_virtio_pci_vector_release_one(proxy, vdev->queue_sel); > + } does it matter in which order to do this? if we release 1st there's more of a chance use will succeeed. I would also check val != vector if value did not change there is nothing to do. > + } > break; > case VIRTIO_PCI_COMMON_Q_ENABLE: > if (val == 1) { > -- > 2.43.0
On Thu, Apr 11, 2024 at 12:18 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > On Thu, Apr 11, 2024 at 12:12:00AM +0800, Cindy Lu wrote: > > During the booting process of the non-standard image, the behavior of the > > called function in qemu is as follows: > > > > 1. vhost_net_stop() was triggered by guest image. This will call the function > > virtio_pci_set_guest_notifiers() with assgin= false, > > virtio_pci_set_guest_notifiers(） will release the irqfd for vector 0 > > > > 2. virtio_reset() was triggered, this will set configure vector to VIRTIO_NO_VECTOR > > > > 3.vhost_net_start() was called (at this time, the configure vector is > > still VIRTIO_NO_VECTOR) and then call virtio_pci_set_guest_notifiers() with > > assgin=true, so the irqfd for vector 0 is still not "init" during this process > > > > 4. The system continues to boot and sets the vector back to 0. After that > > msix_fire_vector_notifier() was triggered to unmask the vector 0 and meet the crash > > > > To fix the issue, we need to support changing the vector after VIRTIO_CONFIG_S_DRIVER_OK is set. > > > > (gdb) bt > > 0 __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) > > at pthread_kill.c:44 > > 1 0x00007fc87148ec53 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78 > > 2 0x00007fc87143e956 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26 > > 3 0x00007fc8714287f4 in __GI_abort () at abort.c:79 > > 4 0x00007fc87142871b in __assert_fail_base > > (fmt=0x7fc8715bbde0 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x5606413efd53 "ret == 0", file=0x5606413ef87d "../accel/kvm/kvm-all.c", line=1837, function=<optimized out>) at assert.c:92 > > 5 0x00007fc871437536 in __GI___assert_fail > > (assertion=0x5606413efd53 "ret == 0", file=0x5606413ef87d "../accel/kvm/kvm-all.c", line=1837, function=0x5606413f06f0 <__PRETTY_FUNCTION__.19> "kvm_irqchip_commit_routes") at assert.c:101 > > 6 0x0000560640f884b5 in kvm_irqchip_commit_routes (s=0x560642cae1f0) at ../accel/kvm/kvm-all.c:1837 > > 7 0x0000560640c98f8e in virtio_pci_one_vector_unmask > > (proxy=0x560643c65f00, queue_no=4294967295, vector=0, msg=..., n=0x560643c6e4c8) > > at ../hw/virtio/virtio-pci.c:1005 > > 8 0x0000560640c99201 in virtio_pci_vector_unmask (dev=0x560643c65f00, vector=0, msg=...) > > at ../hw/virtio/virtio-pci.c:1070 > > 9 0x0000560640bc402e in msix_fire_vector_notifier (dev=0x560643c65f00, vector=0, is_masked=false) > > at ../hw/pci/msix.c:120 > > 10 0x0000560640bc40f1 in msix_handle_mask_update (dev=0x560643c65f00, vector=0, was_masked=true) > > at ../hw/pci/msix.c:140 > > 11 0x0000560640bc4503 in msix_table_mmio_write (opaque=0x560643c65f00, addr=12, val=0, size=4) > > at ../hw/pci/msix.c:231 > > 12 0x0000560640f26d83 in memory_region_write_accessor > > (mr=0x560643c66540, addr=12, value=0x7fc86b7bc628, size=4, shift=0, mask=4294967295, attrs=...) > > at ../system/memory.c:497 > > 13 0x0000560640f270a6 in access_with_adjusted_size > > > > (addr=12, value=0x7fc86b7bc628, size=4, access_size_min=1, access_size_max=4, access_fn=0x560640f26c8d <memory_region_write_accessor>, mr=0x560643c66540, attrs=...) at ../system/memory.c:573 > > 14 0x0000560640f2a2b5 in memory_region_dispatch_write (mr=0x560643c66540, addr=12, data=0, op=MO_32, attrs=...) > > at ../system/memory.c:1521 > > 15 0x0000560640f37bac in flatview_write_continue > > (fv=0x7fc65805e0b0, addr=4273803276, attrs=..., ptr=0x7fc871e9c028, len=4, addr1=12, l=4, mr=0x560643c66540) > > at ../system/physmem.c:2714 > > 16 0x0000560640f37d0f in flatview_write > > (fv=0x7fc65805e0b0, addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4) at ../system/physmem.c:2756 > > 17 0x0000560640f380bf in address_space_write > > (as=0x560642161ae0 <address_space_memory>, addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4) > > at ../system/physmem.c:2863 > > 18 0x0000560640f3812c in address_space_rw > > (as=0x560642161ae0 <address_space_memory>, addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4, is_write=true) at ../system/physmem.c:2873 > > --Type <RET> for more, q to quit, c to continue without paging-- > > 19 0x0000560640f8aa55 in kvm_cpu_exec (cpu=0x560642f205e0) at ../accel/kvm/kvm-all.c:2915 > > 20 0x0000560640f8d731 in kvm_vcpu_thread_fn (arg=0x560642f205e0) at ../accel/kvm/kvm-accel-ops.c:51 > > 21 0x00005606411949f4 in qemu_thread_start (args=0x560642f292b0) at ../util/qemu-thread-posix.c:541 > > 22 0x00007fc87148cdcd in start_thread (arg=<optimized out>) at pthread_create.c:442 > > 23 0x00007fc871512630 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 > > (gdb) > > Signed-off-by: Cindy Lu <lulu@redhat.com> > > --- > > hw/virtio/virtio-pci.c | 30 ++++++++++++++++++++++++++++++ > > 1 file changed, 30 insertions(+) > > > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > > index 1a7039fb0c..b3b1a4a66f 100644 > > --- a/hw/virtio/virtio-pci.c > > +++ b/hw/virtio/virtio-pci.c > > @@ -1570,7 +1570,22 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr, > > } else { > > val = VIRTIO_NO_VECTOR; > > } > > + vector = vdev->config_vector; > > vdev->config_vector = val; > > + /* > > + * If the value was changed after DRIVER_OK was set, it means that > > + * we need to release the old vector and set up the new vector. > > + */ > > + if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && > > + /*check if use the irqfd*/ > > + (msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled())) { > > + if (val != VIRTIO_NO_VECTOR) { > > + kvm_virtio_pci_vector_use_one(proxy, VIRTIO_CONFIG_IRQ_IDX); > > + } > > + if (vector != VIRTIO_NO_VECTOR) { > > + kvm_virtio_pci_vector_release_one(proxy, VIRTIO_CONFIG_IRQ_IDX); > > + } > > + } > > break; > > case VIRTIO_PCI_COMMON_STATUS: > > if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) { > > @@ -1611,6 +1626,21 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr, > > val = VIRTIO_NO_VECTOR; > > } > > virtio_queue_set_vector(vdev, vdev->queue_sel, val); > > + > > + /* > > + * If the value was changed after DRIVER_OK was set, it means that > > + * we need to release the old vector and set up the new vector. > > + */ > > + if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && > > + /*check if use the irqfd*/ > > by comment style will fix this > > > + (msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled())) { > > + if (val != VIRTIO_NO_VECTOR) { > > + kvm_virtio_pci_vector_use_one(proxy, vdev->queue_sel); > > + } > > + if (vector != VIRTIO_NO_VECTOR) { > > + kvm_virtio_pci_vector_release_one(proxy, vdev->queue_sel); > > + } > > does it matter in which order to do this? > if we release 1st there's more of a chance use will succeeed. > > I would also check val != vector > if value did not change there is nothing to do. > Sure, thanks Michael, will send a new version soon thanks cindy > > + } > > break; > > case VIRTIO_PCI_COMMON_Q_ENABLE: > > if (val == 1) { > > -- > > 2.43.0 >
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 1a7039fb0c..b3b1a4a66f 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -1570,7 +1570,22 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr, } else { val = VIRTIO_NO_VECTOR; } + vector = vdev->config_vector; vdev->config_vector = val; + /* + * If the value was changed after DRIVER_OK was set, it means that + * we need to release the old vector and set up the new vector. + */ + if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && + /*check if use the irqfd*/ + (msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled())) { + if (val != VIRTIO_NO_VECTOR) { + kvm_virtio_pci_vector_use_one(proxy, VIRTIO_CONFIG_IRQ_IDX); + } + if (vector != VIRTIO_NO_VECTOR) { + kvm_virtio_pci_vector_release_one(proxy, VIRTIO_CONFIG_IRQ_IDX); + } + } break; case VIRTIO_PCI_COMMON_STATUS: if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) { @@ -1611,6 +1626,21 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr, val = VIRTIO_NO_VECTOR; } virtio_queue_set_vector(vdev, vdev->queue_sel, val); + + /* + * If the value was changed after DRIVER_OK was set, it means that + * we need to release the old vector and set up the new vector. + */ + if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && + /*check if use the irqfd*/ + (msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled())) { + if (val != VIRTIO_NO_VECTOR) { + kvm_virtio_pci_vector_use_one(proxy, vdev->queue_sel); + } + if (vector != VIRTIO_NO_VECTOR) { + kvm_virtio_pci_vector_release_one(proxy, vdev->queue_sel); + } + } break; case VIRTIO_PCI_COMMON_Q_ENABLE: if (val == 1) {
During the booting process of the non-standard image, the behavior of the called function in qemu is as follows: 1. vhost_net_stop() was triggered by guest image. This will call the function virtio_pci_set_guest_notifiers() with assgin= false, virtio_pci_set_guest_notifiers(） will release the irqfd for vector 0 2. virtio_reset() was triggered, this will set configure vector to VIRTIO_NO_VECTOR 3.vhost_net_start() was called (at this time, the configure vector is still VIRTIO_NO_VECTOR) and then call virtio_pci_set_guest_notifiers() with assgin=true, so the irqfd for vector 0 is still not "init" during this process 4. The system continues to boot and sets the vector back to 0. After that msix_fire_vector_notifier() was triggered to unmask the vector 0 and meet the crash To fix the issue, we need to support changing the vector after VIRTIO_CONFIG_S_DRIVER_OK is set. (gdb) bt 0 __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44 1 0x00007fc87148ec53 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78 2 0x00007fc87143e956 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26 3 0x00007fc8714287f4 in __GI_abort () at abort.c:79 4 0x00007fc87142871b in __assert_fail_base (fmt=0x7fc8715bbde0 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x5606413efd53 "ret == 0", file=0x5606413ef87d "../accel/kvm/kvm-all.c", line=1837, function=<optimized out>) at assert.c:92 5 0x00007fc871437536 in __GI___assert_fail (assertion=0x5606413efd53 "ret == 0", file=0x5606413ef87d "../accel/kvm/kvm-all.c", line=1837, function=0x5606413f06f0 <__PRETTY_FUNCTION__.19> "kvm_irqchip_commit_routes") at assert.c:101 6 0x0000560640f884b5 in kvm_irqchip_commit_routes (s=0x560642cae1f0) at ../accel/kvm/kvm-all.c:1837 7 0x0000560640c98f8e in virtio_pci_one_vector_unmask (proxy=0x560643c65f00, queue_no=4294967295, vector=0, msg=..., n=0x560643c6e4c8) at ../hw/virtio/virtio-pci.c:1005 8 0x0000560640c99201 in virtio_pci_vector_unmask (dev=0x560643c65f00, vector=0, msg=...) at ../hw/virtio/virtio-pci.c:1070 9 0x0000560640bc402e in msix_fire_vector_notifier (dev=0x560643c65f00, vector=0, is_masked=false) at ../hw/pci/msix.c:120 10 0x0000560640bc40f1 in msix_handle_mask_update (dev=0x560643c65f00, vector=0, was_masked=true) at ../hw/pci/msix.c:140 11 0x0000560640bc4503 in msix_table_mmio_write (opaque=0x560643c65f00, addr=12, val=0, size=4) at ../hw/pci/msix.c:231 12 0x0000560640f26d83 in memory_region_write_accessor (mr=0x560643c66540, addr=12, value=0x7fc86b7bc628, size=4, shift=0, mask=4294967295, attrs=...) at ../system/memory.c:497 13 0x0000560640f270a6 in access_with_adjusted_size (addr=12, value=0x7fc86b7bc628, size=4, access_size_min=1, access_size_max=4, access_fn=0x560640f26c8d <memory_region_write_accessor>, mr=0x560643c66540, attrs=...) at ../system/memory.c:573 14 0x0000560640f2a2b5 in memory_region_dispatch_write (mr=0x560643c66540, addr=12, data=0, op=MO_32, attrs=...) at ../system/memory.c:1521 15 0x0000560640f37bac in flatview_write_continue (fv=0x7fc65805e0b0, addr=4273803276, attrs=..., ptr=0x7fc871e9c028, len=4, addr1=12, l=4, mr=0x560643c66540) at ../system/physmem.c:2714 16 0x0000560640f37d0f in flatview_write (fv=0x7fc65805e0b0, addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4) at ../system/physmem.c:2756 17 0x0000560640f380bf in address_space_write (as=0x560642161ae0 <address_space_memory>, addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4) at ../system/physmem.c:2863 18 0x0000560640f3812c in address_space_rw (as=0x560642161ae0 <address_space_memory>, addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4, is_write=true) at ../system/physmem.c:2873 --Type <RET> for more, q to quit, c to continue without paging-- 19 0x0000560640f8aa55 in kvm_cpu_exec (cpu=0x560642f205e0) at ../accel/kvm/kvm-all.c:2915 20 0x0000560640f8d731 in kvm_vcpu_thread_fn (arg=0x560642f205e0) at ../accel/kvm/kvm-accel-ops.c:51 21 0x00005606411949f4 in qemu_thread_start (args=0x560642f292b0) at ../util/qemu-thread-posix.c:541 22 0x00007fc87148cdcd in start_thread (arg=<optimized out>) at pthread_create.c:442 23 0x00007fc871512630 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 (gdb) Signed-off-by: Cindy Lu <lulu@redhat.com> --- hw/virtio/virtio-pci.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)