On Wed, Mar 27, 2024 at 2:03 PM Cindy Lu <l...@redhat.com> wrote: > > On Wed, Mar 27, 2024 at 11:05 AM Jason Wang <jasow...@redhat.com> wrote: > > > > Hi Cindy: > > > > On Wed, Mar 27, 2024 at 9:29 AM Cindy Lu <l...@redhat.com> wrote: > > > > > > we need a crash in Non-standard image, here is the jira for this > > > https://issues.redhat.com/browse/RHEL-28522 > > > The root cause of the issue is that an IRQFD was used without > > > initialization.. > > > > > > During the booting process of the Vyatta image, the behavior of the > > > called function in qemu is as follows: > > > > > > 1. vhost_net_stop() was called, this will call the function > > > virtio_pci_set_guest_notifiers() with assgin= false, and > > > virtio_pci_set_guest_notifiers(） will release the irqfd for vector 0 > > > > Before vhost_net_stop(), do we know which vector is used by which queue? > > > before this stop, vdev->config_verctor is get from > virtio_pci_common_read/virtio_pci_common_write > it was set to vector 0
I basically meant if vector 0 is shared with some virtqueues here. > > > > > > 2. virtio_reset() was called -->set configure vector to VIRTIO_NO_VECTORt > > > > > > 3.vhost_net_start() was called (at this time the configure vector is > > > still VIRTIO_NO_VECTOR) and call virtio_pci_set_guest_notifiers() with > > > assgin= true, so the irqfd for vector 0 was not "init" during this process > > > > How does the configure vector differ from the virtqueue vector here? > > > All the vectors are VIRTIO_NO_VECTOR (including vq). any > msix_fire_vector_notifier() > been called will cause the crash at this time. Won't virtio_pci_set_guest_notifiers() will try to allocate irqfd when the assignment is true? > So I think this should > be a bug in this guest image The point is Qemu should not crash even if the guest driver is buggy. It would be nice if we can have a qtest for this on top. Thanks > > > > > > 4. The system continues to boot and msix_fire_vector_notifier() was > > > called unmask the vector 0 and then met the crash > > > [msix_fire_vector_notifier] 112 called vector 0 is_masked 1 > > > [msix_fire_vector_notifier] 112 called vector 0 is_masked 0 > > > > > > The reason for not reproducing in RHEL/fedora guest image is because > > > REHL/Fedora doesn't have the behavior of calling vhost_net_stop and then > > > virtio_reset, and also won't call msix_fire_vector_notifier for vector 0 > > > during system boot. > > > > > > The reason for not reproducing before configure interrupt support is > > > because > > > vector 0 is for configure interrupt, before the support for configure > > > interrupts, the notifier process will not handle vector 0. > > > > > > For the device Vyatta using, it doesn't support configure interrupts at > > > all, So we plan to disable the configure interrupts in unsupported device > > > > Btw, let's tweak the changelog, it's a little bit hard to understand. > > > sure will do > thanks > Cindy > > Thanks > > > > > > > > Signed-off-by: Cindy Lu <l...@redhat.com> > > > > > > Cindy Lu (2): > > > virtio-net: disable the configure interrupt for not support device > > > virtio-pci: check if the configure interrupt enable > > > > > > hw/net/virtio-net.c | 5 ++++- > > > hw/virtio/virtio-pci.c | 41 +++++++++++++++++++++----------------- > > > hw/virtio/virtio.c | 1 + > > > include/hw/virtio/virtio.h | 1 + > > > 4 files changed, 29 insertions(+), 19 deletions(-) > > > > > > -- > > > 2.43.0 > > > > > >
