hw/virtio/virtio-pci.c | 41 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 39 insertions(+), 2 deletions(-)
From: Cindy Lu <lulu@redhat.com>
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)
MST: coding style and typo fixups
Fixes: f9a09ca3ea ("vhost: add support for configure interrupt")
Cc: qemu-stable@nongnu.org
Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20240412062750.475180-1-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
To expedite fixed lots of style issues myself.
Completely untested - guys can you pls test and ack?
hw/virtio/virtio-pci.c | 41 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 39 insertions(+), 2 deletions(-)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index cb6940fc0e..e9edd57339 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1424,6 +1424,34 @@ static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
return offset;
}
+static void virtio_pci_set_and_change_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 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 +1598,12 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
} else {
val = VIRTIO_NO_VECTOR;
}
- vdev->config_vector = val;
+ vector = vdev->config_vector;
+ /* Check if we need to change the vector. */
+ if (val != vector) {
+ virtio_pci_set_and_change_vector(vdev, proxy, VIRTIO_CONFIG_IRQ_IDX,
+ vector, val);
+ }
break;
case VIRTIO_PCI_COMMON_STATUS:
if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) {
@@ -1610,7 +1643,11 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
} else {
val = VIRTIO_NO_VECTOR;
}
- virtio_queue_set_vector(vdev, vdev->queue_sel, val);
+ /* Check if we need to change the vector. */
+ if (val != vector) {
+ virtio_pci_set_and_change_vector(vdev, proxy, vdev->queue_sel,
+ vector, val);
+ }
break;
case VIRTIO_PCI_COMMON_Q_ENABLE:
if (val == 1) {
--
MST
On 15/4/24 11:19, Michael S. Tsirkin wrote:
> From: Cindy Lu <lulu@redhat.com>
>
> 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.
> MST: coding style and typo fixups
>
> Fixes: f9a09ca3ea ("vhost: add support for configure interrupt")
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> Message-Id: <20240412062750.475180-1-lulu@redhat.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>
> To expedite fixed lots of style issues myself.
> Completely untested - guys can you pls test and ack?
>
>
> hw/virtio/virtio-pci.c | 41 +++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 39 insertions(+), 2 deletions(-)
>
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index cb6940fc0e..e9edd57339 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1424,6 +1424,34 @@ static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
> return offset;
> }
>
> +static void virtio_pci_set_and_change_vector(VirtIODevice *vdev,
> + VirtIOPCIProxy *proxy,
> + int queue_no, uint16_t old_vector,
> + uint16_t new_vector)
> +{
Alternatively:
if (new_vector == old_vector) {
return;
}
> + bool kvm_irqfd = (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
> + msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled();
> +
> + /*
> + * 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 +1598,12 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
> } else {
> val = VIRTIO_NO_VECTOR;
> }
> - vdev->config_vector = val;
> + vector = vdev->config_vector;
> + /* Check if we need to change the vector. */
> + if (val != vector) {
> + virtio_pci_set_and_change_vector(vdev, proxy, VIRTIO_CONFIG_IRQ_IDX,
> + vector, val);
> + }
> break;
On Mon, Apr 15, 2024 at 11:23:46AM +0200, Philippe Mathieu-Daudé wrote:
> On 15/4/24 11:19, Michael S. Tsirkin wrote:
> > From: Cindy Lu <lulu@redhat.com>
> >
> > 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.
>
>
> > MST: coding style and typo fixups
> >
> > Fixes: f9a09ca3ea ("vhost: add support for configure interrupt")
> > Cc: qemu-stable@nongnu.org
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > Message-Id: <20240412062750.475180-1-lulu@redhat.com>
> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> >
> > To expedite fixed lots of style issues myself.
> > Completely untested - guys can you pls test and ack?
> >
> >
> > hw/virtio/virtio-pci.c | 41 +++++++++++++++++++++++++++++++++++++++--
> > 1 file changed, 39 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> > index cb6940fc0e..e9edd57339 100644
> > --- a/hw/virtio/virtio-pci.c
> > +++ b/hw/virtio/virtio-pci.c
> > @@ -1424,6 +1424,34 @@ static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
> > return offset;
> > }
> > +static void virtio_pci_set_and_change_vector(VirtIODevice *vdev,
> > + VirtIOPCIProxy *proxy,
> > + int queue_no, uint16_t old_vector,
> > + uint16_t new_vector)
> > +{
>
> Alternatively:
>
> if (new_vector == old_vector) {
> return;
> }
True. And in fact callers do not need check this.
Let me do v8.
> > + bool kvm_irqfd = (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
> > + msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled();
> > +
> > + /*
> > + * 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 +1598,12 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
> > } else {
> > val = VIRTIO_NO_VECTOR;
> > }
> > - vdev->config_vector = val;
> > + vector = vdev->config_vector;
> > + /* Check if we need to change the vector. */
> > + if (val != vector) {
> > + virtio_pci_set_and_change_vector(vdev, proxy, VIRTIO_CONFIG_IRQ_IDX,
> > + vector, val);
> > + }
> > break;
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