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

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Date:   Thu, 21 Dec 2017 10:06:08 -0800
From:   Jim Mattson <jmattson@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        kvm list <kvm@...r.kernel.org>,
        David Hildenbrand <david@...hat.com>
Subject: Re: [PATCH 2/3] KVM: vmx: simplify MSR bitmap setup

Reviewed-by: Jim Mattson <jmattson@...gle.com>

On Thu, Dec 21, 2017 at 3:51 AM, Paolo Bonzini <pbonzini@...hat.com> 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@...hat.com>
> ---
>         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
>
>