linux-kernel - Re: [PATCH v2 2/3] KVM: VMX: join functions that disable x2apic msr intercepts

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Date:   Fri, 30 Sep 2016 10:29:34 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Radim Krčmář <rkrcmar@...hat.com>,
        linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Wanpeng Li <kernellwp@...il.com>
Subject: Re: [PATCH v2 2/3] KVM: VMX: join functions that disable x2apic msr
 intercepts



On 29/09/2016 22:41, Radim Krčmář wrote:
>  	for (msr = 0x800; msr <= 0x8ff; msr++) {
>  		if (msr == 0x839 /* TMCCT */)
>  			continue;
> -		vmx_disable_intercept_msr_read_x2apic(msr, true);
> +		vmx_disable_intercept_msr_x2apic(msr, MSR_TYPE_R, true);
>  	}
>  
>  	/* TPR */
> -	vmx_disable_intercept_msr_write_x2apic(0x808, true);
> +	vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);
>  	/* EOI */
> -	vmx_disable_intercept_msr_write_x2apic(0x80b, true);
> +	vmx_disable_intercept_msr_x2apic(0x80b, MSR_TYPE_W, true);
>  	/* SELF-IPI */
> -	vmx_disable_intercept_msr_write_x2apic(0x83f, true);
> +	vmx_disable_intercept_msr_x2apic(0x83f, MSR_TYPE_W, true);
>  
>  	/*
>  	 * (enable_apicv && !kvm_vcpu_apicv_active()) ||
>  	 * 	!enable_apicv
>  	 */
>  	/* TPR */
> -	vmx_disable_intercept_msr_read_x2apic(0x808, false);
> -	vmx_disable_intercept_msr_write_x2apic(0x808, false);
> +	vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);

Alternatively you could place the two function calls for 0x808 together:

 	for (msr = 0x800; msr <= 0x8ff; msr++)
		vmx_disable_intercept_msr_x2apic(msr, MSR_TYPE_R, true);

 	/*
	 * TPR reads and writes can be virtualized even if virtual interrupt delivery
         * is not in use.
	 */
	vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);
	vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);

	/* EOI */
	vmx_disable_intercept_msr_x2apic(0x80b, MSR_TYPE_W, true);

 	/* SELF-IPI */
	vmx_disable_intercept_msr_x2apic(0x83f, MSR_TYPE_W, true);

Paolo