[PATCH kernel v4] KVM: PPC: Make KVM_CAP_IRQFD_RESAMPLE support platform dependent

[Alexey Kardashevskiy]

Anyone, ping?

On 02/01/2023 11:43, Alexey Kardashevskiy wrote:
> Paolo, ping?
> 
> 
> On 06/12/2022 15:39, Alexey Kardashevskiy wrote:
>> Paolo, ping? :)
>>
>>
>> On 27/10/2022 18:38, Alexey Kardashevskiy wrote:
>>> Paolo, ping?
>>>
>>>
>>> On 04/10/2022 10:57, Alexey Kardashevskiy 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.
>>>>
>>>> This should cause no behavioural change for other architectures.
>>>>
>>>> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
>>>> Acked-by: Nicholas Piggin <npiggin at gmail.com>
>>>> Acked-by: Marc Zyngier <maz at kernel.org>
>>>> ---
>>>> Changes:
>>>> v4:
>>>> * removed incorrect clause about changing behavoir on MIPS and RISCV
>>>>
>>>> v3:
>>>> * removed all ifdeferry
>>>> * removed the capability for MIPS and RISCV
>>>> * adjusted the commit log about MIPS and RISCV
>>>>
>>>> v2:
>>>> * removed ifdef for ARM64.
>>>> ---
>>>>   arch/arm64/kvm/arm.c       | 1 +
>>>>   arch/powerpc/kvm/powerpc.c | 6 ++++++
>>>>   arch/s390/kvm/kvm-s390.c   | 1 +
>>>>   arch/x86/kvm/x86.c         | 1 +
>>>>   virt/kvm/kvm_main.c        | 1 -
>>>>   5 files changed, 9 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
>>>> index 2ff0ef62abad..d2daa4d375b5 100644
>>>> --- a/arch/arm64/kvm/arm.c
>>>> +++ b/arch/arm64/kvm/arm.c
>>>> @@ -218,6 +218,7 @@ int kvm_vm_ioctl_check_extension(struct kvm 
>>>> *kvm, long ext)
>>>>       case KVM_CAP_VCPU_ATTRIBUTES:
>>>>       case KVM_CAP_PTP_KVM:
>>>>       case KVM_CAP_ARM_SYSTEM_SUSPEND:
>>>> +    case KVM_CAP_IRQFD_RESAMPLE:
>>>>           r = 1;
>>>>           break;
>>>>       case KVM_CAP_SET_GUEST_DEBUG2:
>>>> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
>>>> index fb1490761c87..908ce8bd91c9 100644
>>>> --- a/arch/powerpc/kvm/powerpc.c
>>>> +++ b/arch/powerpc/kvm/powerpc.c
>>>> @@ -593,6 +593,12 @@ 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/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>>>> index edfd4bbd0cba..7521adadb81b 100644
>>>> --- a/arch/s390/kvm/kvm-s390.c
>>>> +++ b/arch/s390/kvm/kvm-s390.c
>>>> @@ -577,6 +577,7 @@ 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:
>>>> +    case KVM_CAP_IRQFD_RESAMPLE:
>>>>           r = 1;
>>>>           break;
>>>>       case KVM_CAP_SET_GUEST_DEBUG2:
>>>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>>>> index 43a6a7efc6ec..2d6c5a8fdf14 100644
>>>> --- a/arch/x86/kvm/x86.c
>>>> +++ b/arch/x86/kvm/x86.c
>>>> @@ -4395,6 +4395,7 @@ int kvm_vm_ioctl_check_extension(struct kvm 
>>>> *kvm, long ext)
>>>>       case KVM_CAP_VAPIC:
>>>>       case KVM_CAP_ENABLE_CAP:
>>>>       case KVM_CAP_VM_DISABLE_NX_HUGE_PAGES:
>>>> +    case KVM_CAP_IRQFD_RESAMPLE:
>>>>           r = 1;
>>>>           break;
>>>>       case KVM_CAP_EXIT_HYPERCALL:
>>>> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
>>>> index 584a5bab3af3..05cf94013f02 100644
>>>> --- a/virt/kvm/kvm_main.c
>>>> +++ b/virt/kvm/kvm_main.c
>>>> @@ -4447,7 +4447,6 @@ 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:
>>>
>>
> 

-- 
Alexey