linux-kernel - Re: [PATCH v2 2/3] KVM: x86: Correct the name for skipping VMENTER l1d flush

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Message-ID: <ec820c56-ad56-f7bf-db0e-1ba6f7cedfd0@intel.com>
Date:   Wed, 24 May 2023 16:25:41 +0800
From:   Xiaoyao Li <xiaoyao.li@...el.com>
To:     Chao Gao <chao.gao@...el.com>, kvm@...r.kernel.org, x86@...nel.org
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/3] KVM: x86: Correct the name for skipping VMENTER
 l1d flush

On 5/24/2023 2:16 PM, Chao Gao wrote:
> There is no VMENTER_L1D_FLUSH_NESTED_VM. It should be
> ARCH_CAP_SKIP_VMENTRY_L1DFLUSH.

Reviewed-by: Xiaoyao Li <xiaoyao.li@...el.com>

> Signed-off-by: Chao Gao <chao.gao@...el.com>
> ---
>   arch/x86/kvm/x86.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 2408b5f554b7..f7838260c183 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1631,7 +1631,7 @@ static u64 kvm_get_arch_capabilities(void)
>   	 * If we're doing cache flushes (either "always" or "cond")
>   	 * we will do one whenever the guest does a vmlaunch/vmresume.
>   	 * If an outer hypervisor is doing the cache flush for us
> -	 * (VMENTER_L1D_FLUSH_NESTED_VM), we can safely pass that
> +	 * (ARCH_CAP_SKIP_VMENTRY_L1DFLUSH), we can safely pass that
>   	 * capability to the guest too, and if EPT is disabled we're not
>   	 * vulnerable.  Overall, only VMENTER_L1D_FLUSH_NEVER will
>   	 * require a nested hypervisor to do a flush of its own.