Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 7 Jun 2023 13:20:38 -0700
From:   Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
To:     Sean Christopherson <seanjc@google.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, Chao Gao <chao.gao@intel.com>,
        Xiaoyao Li <xiaoyao.li@intel.com>
Subject: Re: [PATCH 2/2] KVM: VMX: Drop unnecessary
 vmx_fb_clear_ctrl_available "cache"
Message-ID: <20230607202038.5vsgsrt724qhxnjd@desk>
References: <20230607004311.1420507-1-seanjc@google.com>
 <20230607004311.1420507-3-seanjc@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230607004311.1420507-3-seanjc@google.com>
Precedence: bulk

On Tue, Jun 06, 2023 at 05:43:10PM -0700, Sean Christopherson wrote:
> Now that KVM snapshots the host's MSR_IA32_ARCH_CAPABILITIES, drop the
> similar snapshot/cache of whether or not KVM is allowed to manipulate
> ARCH_CAPABILITIES.FB_CLEAR_CTRL.  The motivation for the cache was

FB_CLEAR_CTRL is a read-only bit, I think you mean
MSR_IA32_MCU_OPT_CTRL.FB_CLEAR_DIS.

> presumably to avoid the RDMSR, e.g. boot_cpu_has_bug() is quite cheap, and
> modifying the vCPU's MSR_IA32_ARCH_CAPABILITIES is an infrequent option
> and a relatively slow path.
> 
> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>

LGTM.

Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>