Sender: Paolo Bonzini <paolo.bonzini@gmail.com>
Message-ID: <6e95b6f7-44dc-7e48-4e6e-81cf85fc11c6@redhat.com>
Date:   Mon, 20 Dec 2021 10:07:00 +0100
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Subject: Re: [PATCH v2 22/23] kvm: x86: Disable interception for IA32_XFD on
 demand
Content-Language: en-US
To:     Jing Liu <jing2.liu@intel.com>, x86@kernel.org,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com
Cc:     seanjc@google.com, jun.nakajima@intel.com, kevin.tian@intel.com,
        jing2.liu@linux.intel.com, guang.zeng@intel.com,
        wei.w.wang@intel.com, yang.zhong@intel.com
References: <20211217153003.1719189-1-jing2.liu@intel.com>
 <20211217153003.1719189-23-jing2.liu@intel.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
In-Reply-To: <20211217153003.1719189-23-jing2.liu@intel.com>
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Precedence: bulk

On 12/17/21 16:30, Jing Liu wrote:
> +++ b/arch/x86/kvm/x86.c
> @@ -3686,6 +3686,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
>   			return 1;
>   
>   		fpu_update_guest_xfd(&vcpu->arch.guest_fpu, data);
> +
> +		if (data && kvm_x86_ops.set_xfd_passthrough)
> +			static_call(kvm_x86_set_xfd_passthrough)(vcpu);
>   		break;
>   	case MSR_IA32_XFD_ERR:


Please instead add a "case" to vmx_set_msr:

	case MSR_IA32_XFD:
		ret = kvm_set_msr_common(vcpu, msr_info);
		if (!ret && data) {
			vmx_disable_intercept_for_msr(vcpu, MSR_IA32_XFD, MSR_TYPE_RW);
			vcpu->arch.xfd_out_of_sync = true;
		}
		break;

Paolo