Re: [PATCH 2/3] KVM: vmx: simplify MSR bitmap setup

From: Jim Mattson
Date: Thu Dec 21 2017 - 13:06:16 EST


Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>

On Thu, Dec 21, 2017 at 3:51 AM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
> The APICv-enabled MSR bitmap passes through all MSRs in the
> APICv-disabled bitmap (and then some). Make that obvious in
> vmx_disable_intercept_msr_x2apic.
>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
> v1->v2: included the right version of the patch
>
> arch/x86/kvm/vmx.c | 14 ++++++--------
> 1 file changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 2b27afc93cb4..68239aabec52 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5257,14 +5257,13 @@ static void pt_disable_intercept_for_msr(bool flag)
> }
> }
>
> -static void vmx_disable_intercept_msr_x2apic(u32 msr, int type, bool apicv_active)
> +static void vmx_disable_intercept_msr_x2apic(u32 msr, int type, bool apicv_only)
> {
> - if (apicv_active) {
> - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv,
> - msr, type);
> - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv,
> - msr, type);
> - } else {
> + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv,
> + msr, type);
> + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv,
> + msr, type);
> + if (!apicv_only) {
> __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic,
> msr, type);
> __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic,
> @@ -7149,7 +7148,6 @@ static __init int hardware_setup(void)
> * TPR reads and writes can be virtualized even if virtual interrupt
> * delivery is not in use.
> */
> - vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_W, true);
> vmx_disable_intercept_msr_x2apic(0x808, MSR_TYPE_R | MSR_TYPE_W, false);
>
> /* EOI */
> --
> 1.8.3.1
>
>