From ccd8ffa5cd7f9bcfddeda7a9fa1ad86d4bad870e Mon Sep 17 00:00:00 2001 From: Cindy Lu Date: Fri, 12 Apr 2024 14:26:55 +0800 Subject: [PATCH] virtio-pci: fix use of a released vector MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Cindy Lu RH-MergeRequest: 366: virtio-pci: fix use of a released vector RH-Jira: RHEL-32837 RH-Acked-by: Laurent Vivier RH-Acked-by: Jason Wang RH-Commit: [1/1] edd26ffb8727635310aed42e42925afe87df2287 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=, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44 1 0x00007fc87148ec53 in __pthread_kill_internal (signo=6, threadid=) 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=) 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 , 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 , addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4) at ../system/physmem.c:2863 18 0x0000560640f3812c in address_space_rw (as=0x560642161ae0 , addr=4273803276, attrs=..., buf=0x7fc871e9c028, len=4, is_write=true) at ../system/physmem.c:2873 --Type 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=) at pthread_create.c:442 23 0x00007fc871512630 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 (gdb) MST: coding style and typo fixups Fixes: f9a09ca3ea ("vhost: add support for configure interrupt") Cc: qemu-stable@nongnu.org Signed-off-by: Cindy Lu Message-ID: <2321ade5f601367efe7380c04e3f61379c59b48f.1713173550.git.mst@redhat.com> Cc: Lei Yang Cc: Jason Wang Signed-off-by: Michael S. Tsirkin Tested-by: Cindy Lu (cherry picked from commit 2ce6cff94df2650c460f809e5ad263f1d22507c0) Signed-off-by: Cindy Lu --- hw/virtio/virtio-pci.c | 37 +++++++++++++++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-) diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index e433879542..08faefe29a 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -1424,6 +1424,38 @@ static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy, return offset; } +static void virtio_pci_set_vector(VirtIODevice *vdev, + VirtIOPCIProxy *proxy, + int queue_no, uint16_t old_vector, + uint16_t new_vector) +{ + bool kvm_irqfd = (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && + msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled(); + + if (new_vector == old_vector) { + return; + } + + /* + * If the device uses irqfd and the vector changes after DRIVER_OK is + * set, we need to release the old vector and set up the new one. + * Otherwise just need to set the new vector on the device. + */ + if (kvm_irqfd && old_vector != VIRTIO_NO_VECTOR) { + kvm_virtio_pci_vector_release_one(proxy, queue_no); + } + /* Set the new vector on the device. */ + if (queue_no == VIRTIO_CONFIG_IRQ_IDX) { + vdev->config_vector = new_vector; + } else { + virtio_queue_set_vector(vdev, queue_no, new_vector); + } + /* If the new vector changed need to set it up. */ + if (kvm_irqfd && new_vector != VIRTIO_NO_VECTOR) { + kvm_virtio_pci_vector_use_one(proxy, queue_no); + } +} + int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy, uint8_t bar, uint64_t offset, uint64_t length, uint8_t id) @@ -1570,7 +1602,8 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr, } else { val = VIRTIO_NO_VECTOR; } - vdev->config_vector = val; + virtio_pci_set_vector(vdev, proxy, VIRTIO_CONFIG_IRQ_IDX, + vdev->config_vector, val); break; case VIRTIO_PCI_COMMON_STATUS: if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) { @@ -1610,7 +1643,7 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr, } else { val = VIRTIO_NO_VECTOR; } - virtio_queue_set_vector(vdev, vdev->queue_sel, val); + virtio_pci_set_vector(vdev, proxy, vdev->queue_sel, vector, val); break; case VIRTIO_PCI_COMMON_Q_ENABLE: if (val == 1) { -- 2.39.3