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 <l...@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*/
+ (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) {
--
2.43.0
