On Thu, 2 Mar 2023 at 12:37, Paolo Bonzini <pbonz...@redhat.com> wrote:
>
> From: David Woodhouse <d...@amazon.co.uk>
>
> The way that Xen handles MSI PIRQs is kind of awful.
> Now that this is working we can finally enable XENFEAT_hvm_pirqs and
> let the guest use it all.
>
Hi; Coverity points out a logic error in this code (CID 1507603):
> @@ -1638,6 +1877,7 @@ int xen_physdev_unmap_pirq(struct physdev_unmap_pirq
> *unmap)
>
> /* We can only unmap GSI PIRQs */
> if (gsi < 0) {
> + qemu_mutex_unlock(&s->port_lock);
> return -EINVAL;
> }
One of the things xen_physdev_unmap_pirq() does early is return
if gsi is a negative value...
> @@ -1646,6 +1886,12 @@ int xen_physdev_unmap_pirq(struct physdev_unmap_pirq
> *unmap)
> pirq_inuse_word(s, pirq) &= ~pirq_inuse_bit(pirq);
>
> trace_kvm_xen_unmap_pirq(pirq, gsi);
> + qemu_mutex_unlock(&s->port_lock);
> +
> + if (gsi == IRQ_MSI_EMU) {
...but then later we try to test to see if it is IRQ_MSI_EMU.
IRQ_MSI_EMU is -3, so this condition can never be true.
> + kvm_update_msi_routes_all(NULL, true, 0, 0);
> + }
What was the intention here ?
> +
> return 0;
> }
thanks
-- PMM
