On Tue, Nov 29, 2022, Maxim Levitsky wrote:
> This patch adds two new vendor callbacks:
No "this patch" please, just say what it does.
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 684a5519812fb2..46993ce61c92db 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -871,8 +871,13 @@ struct kvm_vcpu_arch {
> u64 tsc_scaling_ratio; /* current scaling ratio */
>
> atomic_t nmi_queued; /* unprocessed asynchronous NMIs */
> - unsigned nmi_pending; /* NMI queued after currently running handler */
> +
> + unsigned int nmi_pending; /*
> + * NMI queued after currently running handler
> + * (not including a hardware pending NMI (e.g vNMI))
> + */
Put the block comment above. I'd say collapse all of the comments about NMIs into
a single big block comment.
> bool nmi_injected; /* Trying to inject an NMI this entry */
> +
> bool smi_pending; /* SMI queued after currently running handler */
> u8 handling_intr_from_guest;
>
> @@ -10015,13 +10022,34 @@ static void process_nmi(struct kvm_vcpu *vcpu)
> * Otherwise, allow two (and we'll inject the first one immediately).
> */
> if (static_call(kvm_x86_get_nmi_mask)(vcpu) || vcpu->arch.nmi_injected)
> - limit = 1;
> + limit--;
> +
> + /* Also if there is already a NMI hardware queued to be injected,
> + * decrease the limit again
> + */
/*
* Block comment ...
*/
> + if (static_call(kvm_x86_get_hw_nmi_pending)(vcpu))
I'd prefer "is_hw_nmi_pending()" over "get", even if it means not pairing with
"set". Though I think that's a good thing since they aren't perfect pairs.
> + limit--;
>
> - vcpu->arch.nmi_pending += atomic_xchg(&vcpu->arch.nmi_queued, 0);
> + if (limit <= 0)
> + return;
> +
> + /* Attempt to use hardware NMI queueing */
> + if (static_call(kvm_x86_set_hw_nmi_pending)(vcpu)) {
> + limit--;
> + nmi_to_queue--;
> + }
> +
> + vcpu->arch.nmi_pending += nmi_to_queue;
> vcpu->arch.nmi_pending = min(vcpu->arch.nmi_pending, limit);
> kvm_make_request(KVM_REQ_EVENT, vcpu);
> }
>
> +/* Return total number of NMIs pending injection to the VM */
> +int kvm_get_total_nmi_pending(struct kvm_vcpu *vcpu)
> +{
> + return vcpu->arch.nmi_pending + static_call(kvm_x86_get_hw_nmi_pending)(vcpu);
Nothing cares about the total count, this can just be;
bool kvm_is_nmi_pending(struct kvm_vcpu *vcpu)
{
return vcpu->arch.nmi_pending ||
static_call(kvm_x86_is_hw_nmi_pending)(vcpu);
}
> +}
> +
> void kvm_make_scan_ioapic_request_mask(struct kvm *kvm,
> unsigned long *vcpu_bitmap)
> {
> --
> 2.26.3
>
