diff options
| author | Xiubo Li <lixiubo@cmss.chinamobile.com> | 2016-06-15 18:00:33 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-06-16 09:38:15 +0200 |
| commit | caf1ff26e1aa178133df68ac3d40815fed2187d9 (patch) | |
| tree | 8afdedf84a552d57f0a2a63422c213ead92acd27 /virt | |
| parent | 5b8abf1f33ccd9f1cbc4248ade3cd507d9319c48 (diff) | |
| download | lwn-caf1ff26e1aa178133df68ac3d40815fed2187d9.tar.gz lwn-caf1ff26e1aa178133df68ac3d40815fed2187d9.zip | |
kvm: Fix irq route entries exceeding KVM_MAX_IRQ_ROUTES
These days, we experienced one guest crash with 8 cores and 3 disks,
with qemu error logs as bellow:
qemu-system-x86_64: /build/qemu-2.0.0/kvm-all.c:984:
kvm_irqchip_commit_routes: Assertion `ret == 0' failed.
And then we found one patch(bdf026317d) in qemu tree, which said
could fix this bug.
Execute the following script will reproduce the BUG quickly:
irq_affinity.sh
========================================================================
vda_irq_num=25
vdb_irq_num=27
while [ 1 ]
do
for irq in {1,2,4,8,10,20,40,80}
do
echo $irq > /proc/irq/$vda_irq_num/smp_affinity
echo $irq > /proc/irq/$vdb_irq_num/smp_affinity
dd if=/dev/vda of=/dev/zero bs=4K count=100 iflag=direct
dd if=/dev/vdb of=/dev/zero bs=4K count=100 iflag=direct
done
done
========================================================================
The following qemu log is added in the qemu code and is displayed when
this bug reproduced:
kvm_irqchip_commit_routes: max gsi: 1008, nr_allocated_irq_routes: 1024,
irq_routes->nr: 1024, gsi_count: 1024.
That's to say when irq_routes->nr == 1024, there are 1024 routing entries,
but in the kernel code when routes->nr >= 1024, will just return -EINVAL;
The nr is the number of the routing entries which is in of
[1 ~ KVM_MAX_IRQ_ROUTES], not the index in [0 ~ KVM_MAX_IRQ_ROUTES - 1].
This patch fix the BUG above.
Cc: stable@vger.kernel.org
Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: Zhang Zhuoyu <zhangzhuoyu@cmss.chinamobile.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 02e98f3131bd..48bd520fc702 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2941,7 +2941,7 @@ static long kvm_vm_ioctl(struct file *filp, if (copy_from_user(&routing, argp, sizeof(routing))) goto out; r = -EINVAL; - if (routing.nr >= KVM_MAX_IRQ_ROUTES) + if (routing.nr > KVM_MAX_IRQ_ROUTES) goto out; if (routing.flags) goto out; |