On Tue, Aug 6, 2024 at 5:37 PM Cindy Lu <l...@redhat.com> wrote: > > The crash was reported in MAC OS and NixOS, here is the link for this bug > https://gitlab.com/qemu-project/qemu/-/issues/2334 > https://gitlab.com/qemu-project/qemu/-/issues/2321 > > In this bug, they are using the virtio_input device. The guest notifier was > not supported for this device, The function virtio_pci_set_guest_notifiers() > was not called, and the vector_irqfd was not initialized. > > So the fix is adding the check for vector_irqfd in virtio_pci_get_notifier() > > The function virtio_pci_get_notifier() can be used in various devices. > It could also be called when VIRTIO_CONFIG_S_DRIVER_OK is not set. In this > situation, > the vector_irqfd being NULL is acceptable. We can allow the device continue > to boot > > If the vector_irqfd still hasn't been initialized after > VIRTIO_CONFIG_S_DRIVER_OK > is set, it means that the function set_guest_notifiers was not called before > the > driver started. This indicates that the device is not using the notifier. > At this point, we will let the check fail. > > This fix is verified in vyatta,MacOS,NixOS,fedora system. > > The bt tree for this bug is: > Thread 6 "CPU 0/KVM" received signal SIGSEGV, Segmentation fault. > [Switching to Thread 0x7c817be006c0 (LWP 1269146)] > kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817 > 817 if (irqfd->users == 0) { > (gdb) thread apply all bt > ... > Thread 6 (Thread 0x7c817be006c0 (LWP 1269146) "CPU 0/KVM"): > 0 kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817 > 1 kvm_virtio_pci_vector_use_one () at > ../qemu-9.0.0/hw/virtio/virtio-pci.c:893 > 2 0x00005983657045e2 in memory_region_write_accessor () at > ../qemu-9.0.0/system/memory.c:497 > 3 0x0000598365704ba6 in access_with_adjusted_size () at > ../qemu-9.0.0/system/memory.c:573 > 4 0x0000598365705059 in memory_region_dispatch_write () at > ../qemu-9.0.0/system/memory.c:1528 > 5 0x00005983659b8e1f in flatview_write_continue_step.isra.0 () at > ../qemu-9.0.0/system/physmem.c:2713 > 6 0x000059836570ba7d in flatview_write_continue () at > ../qemu-9.0.0/system/physmem.c:2743 > 7 flatview_write () at ../qemu-9.0.0/system/physmem.c:2774 > 8 0x000059836570bb76 in address_space_write () at > ../qemu-9.0.0/system/physmem.c:2894 > 9 0x0000598365763afe in address_space_rw () at > ../qemu-9.0.0/system/physmem.c:2904 > 10 kvm_cpu_exec () at ../qemu-9.0.0/accel/kvm/kvm-all.c:2917 > 11 0x000059836576656e in kvm_vcpu_thread_fn () at > ../qemu-9.0.0/accel/kvm/kvm-accel-ops.c:50 > 12 0x0000598365926ca8 in qemu_thread_start () at > ../qemu-9.0.0/util/qemu-thread-posix.c:541 > 13 0x00007c8185bcd1cf in ??? () at /usr/lib/libc.so.6 > 14 0x00007c8185c4e504 in clone () at /usr/lib/libc.so.6 > > Fixes: 2ce6cff94d ("virtio-pci: fix use of a released vector") > Cc: qemu-sta...@nongnu.org > Signed-off-by: Cindy Lu <l...@redhat.com> > ---
Acked-by: Jason Wang <jasow...@redhat.com> Thanks
