Re: [PATCH v5 2/6] LoongArch: KVM: Check msgint feature in interrupt post

[Huacai Chen]

On Wed, Jun 10, 2026 at 4:04 PM Bibo Mao <maobibo@xxxxxxxxxxx> wrote:
>
>
>
> On 2026/6/10 下午3:37, Huacai Chen wrote:
> > On Sat, Jun 6, 2026 at 5:54 PM Huacai Chen <chenhuacai@xxxxxxxxxx> wrote:
> >>
> >> Hi, Bibo,
> >>
> >> On Tue, May 26, 2026 at 8:53 PM Bibo Mao <maobibo@xxxxxxxxxxx> wrote:
> >>>
> >>> Interrupt AVEC is valid only if VM has msgint feature, and this feature
> >>> is checked in interrupt handling. Since interrupt handling is executing
> >>> in VM context switch, and it is hot path, here move the feature checking
> >>> in interrupt post rather than interrupt handling.
> >>>
> >>> Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
> >>> ---
> >>>   arch/loongarch/kvm/interrupt.c |  5 -----
> >>>   arch/loongarch/kvm/vcpu.c      | 14 +++++++++-----
> >>>   2 files changed, 9 insertions(+), 10 deletions(-)
> >>>
> >>> diff --git a/arch/loongarch/kvm/interrupt.c b/arch/loongarch/kvm/interrupt.c
> >>> index a18c60dffbba..48dd56aa4dc5 100644
> >>> --- a/arch/loongarch/kvm/interrupt.c
> >>> +++ b/arch/loongarch/kvm/interrupt.c
> >>> @@ -36,8 +36,6 @@ static int kvm_irq_deliver(struct kvm_vcpu *vcpu, unsigned int priority)
> >>>
> >>>          switch (priority) {
> >>>          case INT_AVEC:
> >>> -               if (!kvm_guest_has_msgint(&vcpu->arch))
> >>> -                       break;
> >>>                  dmsintc_inject_irq(vcpu);
> >>>                  fallthrough;
> >>>          case INT_TI:
> >>> @@ -75,9 +73,6 @@ static int kvm_irq_clear(struct kvm_vcpu *vcpu, unsigned int priority)
> >>>
> >>>          switch (priority) {
> >>>          case INT_AVEC:
> >>> -               if (!kvm_guest_has_msgint(&vcpu->arch))
> >>> -                       break;
> >>> -               fallthrough;
> >>>          case INT_TI:
> >>>          case INT_IPI:
> >>>          case INT_SWI0:
> >>> diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
> >>> index df5be9b265e8..ebd432da3ca4 100644
> >>> --- a/arch/loongarch/kvm/vcpu.c
> >>> +++ b/arch/loongarch/kvm/vcpu.c
> >>> @@ -1493,14 +1493,18 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
> >>>          if (vector >= EXCCODE_INT_NUM)
> >>>                  return -EINVAL;
> >>>
> >>> -       if (intr > 0)
> >>> +       if (!kvm_guest_has_msgint(&vcpu->arch) && (vector == INT_AVEC))
> >>> +               return -EINVAL;
> >>> +
> >>> +       /*
> >>> +        * Clear irq with INT_SWI0 (which is 0) is missing from SW side
> >>> +        * INT_SWI0 is cleared by guest kernel with the similar instruction
> >>> +        * clear_csr_estat(1 << INT_SWI0)
> >>> +        */
> >>> +       if (intr >= 0)
> >>>                  kvm_queue_irq(vcpu, intr);
> >>>          else if (intr < 0)
> >> I think "else if (intr < 0)" can be simplified as "else".
> > Any updates for this series?
> Sorry, I do not notice it.
> yes, it can be simplified in this way. Will refresh it in next version.
Then you probably missed this, too.
https://lore.kernel.org/loongarch/20260526125256.2511876-1-maobibo@xxxxxxxxxxx/T/#m05744b66990b2ae0c4511820eb903237c00d290c

Huacai

>
> Regards
> Bibo Mao
> >
> >
> > Huacai
> >
> >>
> >>
> >> Huacai
> >>
> >>>                  kvm_dequeue_irq(vcpu, -intr);
> >>> -       else {
> >>> -               kvm_err("%s: invalid interrupt ioctl %d\n", __func__, irq->irq);
> >>> -               return -EINVAL;
> >>> -       }
> >>>
> >>>          kvm_vcpu_kick(vcpu);
> >>>
> >>> --
> >>> 2.39.3
> >>>
> >>>
>