linux-kernel - Re: [PATCH v2 3/6] KVM: selftests: Test Hyper-V extended hypercall enablement

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Message-ID: <87h6yrou4k.fsf@ovpn-194-185.brq.redhat.com>
Date:   Tue, 22 Nov 2022 17:02:03 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Vipin Sharma <vipinsh@...gle.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        seanjc@...gle.com, pbonzini@...hat.com, dmatlack@...gle.com
Subject: Re: [PATCH v2 3/6] KVM: selftests: Test Hyper-V extended hypercall
 enablement

Vipin Sharma <vipinsh@...gle.com> writes:

> Test Hyper-V extended hypercall, HV_EXT_CALL_QUERY_CAPABILITIES
> (0x8001), access denied and invalid parameter
> cases.
>
> Access is denied if CPUID.0x40000003.EBX BIT(20) is not set.
> Invalid parameter if call has fast bit set.
>
> Signed-off-by: Vipin Sharma <vipinsh@...gle.com>
> ---
>  tools/testing/selftests/kvm/include/x86_64/hyperv.h  | 4 ++++
>  tools/testing/selftests/kvm/x86_64/hyperv_features.c | 9 +++++++++
>  2 files changed, 13 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/x86_64/hyperv.h b/tools/testing/selftests/kvm/include/x86_64/hyperv.h
> index 9218bb5f44bf..8813c1bb74a0 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/hyperv.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/hyperv.h
> @@ -112,6 +112,7 @@
>  #define HV_ACCESS_STATS				BIT(8)
>  #define HV_DEBUGGING				BIT(11)
>  #define HV_CPU_MANAGEMENT			BIT(12)
> +#define HV_ENABLE_EXTENDED_HYPERCALLS		BIT(20)
>  #define HV_ISOLATION				BIT(22)
>  
>  /* HYPERV_CPUID_FEATURES.EDX */
> @@ -166,6 +167,9 @@
>  #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af
>  #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0
>  
> +/* Extended hypercalls */
> +#define HV_EXT_CALL_QUERY_CAPABILITIES		0x8001
> +
>  #define HV_FLUSH_ALL_PROCESSORS			BIT(0)
>  #define HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES	BIT(1)
>  #define HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY	BIT(2)
> diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_features.c b/tools/testing/selftests/kvm/x86_64/hyperv_features.c
> index 3163c3e8db0a..a5a3146fc299 100644
> --- a/tools/testing/selftests/kvm/x86_64/hyperv_features.c
> +++ b/tools/testing/selftests/kvm/x86_64/hyperv_features.c
> @@ -583,6 +583,15 @@ static void guest_test_hcalls_access(void)
>  			hcall->expect = HV_STATUS_SUCCESS;
>  			break;
>  		case 19:
> +			hcall->control = HV_EXT_CALL_QUERY_CAPABILITIES;
> +			hcall->expect = HV_STATUS_ACCESS_DENIED;
> +			break;
> +		case 20:
> +			feat->ebx |= HV_ENABLE_EXTENDED_HYPERCALLS;

As I've mentioned on another patch, things look significantly better
after https://lore.kernel.org/kvm/20221013095849.705943-6-vkuznets@redhat.com/
cleanup, hope we can have it in soon.

> +			hcall->control = HV_EXT_CALL_QUERY_CAPABILITIES | HV_HYPERCALL_FAST_BIT;
> +			hcall->expect = HV_STATUS_INVALID_PARAMETER;
> +			break;
> +		case 21:
>  			kvm_vm_free(vm);
>  			return;
>  		}

-- 
Vitaly