Re: [PATCH v3 4/4] KVM: hyper-v: Advertise support for fast XMM hypercalls

From: Paolo Bonzini <pbonzini@redhat.com>
To: Siddharth Chandrasekaran <sidcha@amazon.de>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Wei Liu <wei.liu@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>
Cc: Alexander Graf <graf@amazon.com>,
	Evgeny Iakovlev <eyakovl@amazon.de>,
	Liran Alon <liran@amazon.com>,
	Ioannis Aslanidis <iaslan@amazon.de>,
	linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org
Subject: Re: [PATCH v3 4/4] KVM: hyper-v: Advertise support for fast XMM hypercalls
Date: Mon, 24 May 2021 14:00:22 +0200	[thread overview]
Message-ID: <17a1ab38-10db-4fdf-411e-921738cd94e1@redhat.com> (raw)
In-Reply-To: <33a7e27046c15134667ea891feacbe3fe208f66e.1618349671.git.sidcha@amazon.de>

On 13/04/21 23:50, Siddharth Chandrasekaran wrote:
> Now that kvm_hv_flush_tlb() has been patched to support XMM hypercall
> inputs, we can start advertising this feature to guests.
> 
> Cc: Alexander Graf <graf@amazon.com>
> Cc: Evgeny Iakovlev <eyakovl@amazon.de>
> Signed-off-by: Siddharth Chandrasekaran <sidcha@amazon.de>
> ---
>   arch/x86/include/asm/hyperv-tlfs.h | 7 ++++++-
>   arch/x86/kvm/hyperv.c              | 1 +
>   2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> index ee6336a54f92..597ae1142864 100644
> --- a/arch/x86/include/asm/hyperv-tlfs.h
> +++ b/arch/x86/include/asm/hyperv-tlfs.h
> @@ -52,7 +52,7 @@
>    * Support for passing hypercall input parameter block via XMM
>    * registers is available
>    */
> -#define HV_X64_HYPERCALL_PARAMS_XMM_AVAILABLE		BIT(4)
> +#define HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE		BIT(4)
>   /* Support for a virtual guest idle state is available */
>   #define HV_X64_GUEST_IDLE_STATE_AVAILABLE		BIT(5)
>   /* Frequency MSRs available */
> @@ -61,6 +61,11 @@
>   #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE		BIT(10)
>   /* Support for debug MSRs available */
>   #define HV_FEATURE_DEBUG_MSRS_AVAILABLE			BIT(11)
> +/*
> + * Support for returning hypercall output block via XMM
> + * registers is available
> + */
> +#define HV_X64_HYPERCALL_XMM_OUTPUT_AVAILABLE		BIT(15)
>   /* stimer Direct Mode is available */
>   #define HV_STIMER_DIRECT_MODE_AVAILABLE			BIT(19)
>   
> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
> index cd6c6f1f06a4..0f6fd7550510 100644
> --- a/arch/x86/kvm/hyperv.c
> +++ b/arch/x86/kvm/hyperv.c
> @@ -2235,6 +2235,7 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
>   			ent->ebx |= HV_POST_MESSAGES;
>   			ent->ebx |= HV_SIGNAL_EVENTS;
>   
> +			ent->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
>   			ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
>   			ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
>   
> 

Queued, thanks.

Paolo