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References: <20220504074807.3616813-1-aik@ozlabs.ru>
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From:   Anup Patel <anup@brainfault.org>
Date:   Fri, 16 Sep 2022 10:37:53 +0530
Message-ID: <CAAhSdy0hxHjQkVj8TLPh4j=vBrX1QoZcJXNeRBPtf5ozdjQaTQ@mail.gmail.com>
Subject: Re: [PATCH kernel] KVM: PPC: Make KVM_CAP_IRQFD_RESAMPLE platform dependent
To:     Alexey Kardashevskiy <aik@ozlabs.ru>
Cc:     kvm-ppc@vger.kernel.org, x86@kernel.org,
        linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org,
        linux-riscv@lists.infradead.org, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
        kvm-riscv@lists.infradead.org,
        Alex Williamson <alex.williamson@redhat.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Fabiano Rosas <farosas@linux.ibm.com>
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Precedence: bulk

On Wed, May 4, 2022 at 1:18 PM Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>
> When introduced, IRQFD resampling worked on POWER8 with XICS. However
> KVM on POWER9 has never implemented it - the compatibility mode code
> ("XICS-on-XIVE") misses the kvm_notify_acked_irq() call and the native
> XIVE mode does not handle INTx in KVM at all.
>
> This moved the capability support advertising to platforms and stops
> advertising it on XIVE, i.e. POWER9 and later.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
>
>
> Or I could move this one together with KVM_CAP_IRQFD. Thoughts?

For KVM RISC-V:
Acked-by: Anup Patel <anup@brainfault.org>

Thanks,
Anup

>
> ---
>  arch/arm64/kvm/arm.c       | 3 +++
>  arch/mips/kvm/mips.c       | 3 +++
>  arch/powerpc/kvm/powerpc.c | 6 ++++++
>  arch/riscv/kvm/vm.c        | 3 +++
>  arch/s390/kvm/kvm-s390.c   | 3 +++
>  arch/x86/kvm/x86.c         | 3 +++
>  virt/kvm/kvm_main.c        | 1 -
>  7 files changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 523bc934fe2f..092f0614bae3 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -210,6 +210,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>         case KVM_CAP_SET_GUEST_DEBUG:
>         case KVM_CAP_VCPU_ATTRIBUTES:
>         case KVM_CAP_PTP_KVM:
> +#ifdef CONFIG_HAVE_KVM_IRQFD
> +       case KVM_CAP_IRQFD_RESAMPLE:
> +#endif
>                 r = 1;
>                 break;
>         case KVM_CAP_SET_GUEST_DEBUG2:
> diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
> index a25e0b73ee70..0f3de470a73e 100644
> --- a/arch/mips/kvm/mips.c
> +++ b/arch/mips/kvm/mips.c
> @@ -1071,6 +1071,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>         case KVM_CAP_READONLY_MEM:
>         case KVM_CAP_SYNC_MMU:
>         case KVM_CAP_IMMEDIATE_EXIT:
> +#ifdef CONFIG_HAVE_KVM_IRQFD
> +       case KVM_CAP_IRQFD_RESAMPLE:
> +#endif
>                 r = 1;
>                 break;
>         case KVM_CAP_NR_VCPUS:
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 875c30c12db0..87698ffef3be 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -591,6 +591,12 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>                 break;
>  #endif
>
> +#ifdef CONFIG_HAVE_KVM_IRQFD
> +       case KVM_CAP_IRQFD_RESAMPLE:
> +               r = !xive_enabled();
> +               break;
> +#endif
> +
>         case KVM_CAP_PPC_ALLOC_HTAB:
>                 r = hv_enabled;
>                 break;
> diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c
> index c768f75279ef..b58579b386bb 100644
> --- a/arch/riscv/kvm/vm.c
> +++ b/arch/riscv/kvm/vm.c
> @@ -63,6 +63,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>         case KVM_CAP_READONLY_MEM:
>         case KVM_CAP_MP_STATE:
>         case KVM_CAP_IMMEDIATE_EXIT:
> +#ifdef CONFIG_HAVE_KVM_IRQFD
> +       case KVM_CAP_IRQFD_RESAMPLE:
> +#endif
>                 r = 1;
>                 break;
>         case KVM_CAP_NR_VCPUS:
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 156d1c25a3c1..85e093fc8d13 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -564,6 +564,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>         case KVM_CAP_SET_GUEST_DEBUG:
>         case KVM_CAP_S390_DIAG318:
>         case KVM_CAP_S390_MEM_OP_EXTENSION:
> +#ifdef CONFIG_HAVE_KVM_IRQFD
> +       case KVM_CAP_IRQFD_RESAMPLE:
> +#endif
>                 r = 1;
>                 break;
>         case KVM_CAP_SET_GUEST_DEBUG2:
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 0c0ca599a353..a0a7b769483d 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -4273,6 +4273,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>         case KVM_CAP_SYS_ATTRIBUTES:
>         case KVM_CAP_VAPIC:
>         case KVM_CAP_ENABLE_CAP:
> +#ifdef CONFIG_HAVE_KVM_IRQFD
> +       case KVM_CAP_IRQFD_RESAMPLE:
> +#endif
>                 r = 1;
>                 break;
>         case KVM_CAP_EXIT_HYPERCALL:
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 70e05af5ebea..885e72e668a5 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -4293,7 +4293,6 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
>  #endif
>  #ifdef CONFIG_HAVE_KVM_IRQFD
>         case KVM_CAP_IRQFD:
> -       case KVM_CAP_IRQFD_RESAMPLE:
>  #endif
>         case KVM_CAP_IOEVENTFD_ANY_LENGTH:
>         case KVM_CAP_CHECK_EXTENSION_VM:
> --
> 2.30.2
>