Re: [PATCH 3/3] X86/nVMX: Update the MSR_BITMAP field with the L02 MSR BITMAP

From: Jim Mattson
Date: Fri Feb 09 2018 - 18:26:58 EST


On Thu, Feb 8, 2018 at 2:53 PM, KarimAllah Ahmed <karahmed@xxxxxxxxx> wrote:
> ... otherwise we will just be running with the L1 MSR BITMAP!
>
> It does not seem that we ever update the MSR_BITMAP when the nested guest
> is running. The only place where we update the MSR_BITMAP field in VMCS is
> for the L1 guest!
>
> Signed-off-by: KarimAllah Ahmed <karahmed@xxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
> Cc: kvm@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
> arch/x86/kvm/vmx.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 91e3539..f40be10 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -10589,6 +10589,9 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
> vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base);
> vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base);
>
> + if (cpu_has_vmx_msr_bitmap())
> + vmcs_write64(MSR_BITMAP, __pa(vmx->nested.vmcs02.msr_bitmap));
> +

This is already in David's "[PATCH 5/9] KVM: VMX: make MSR bitmaps
per-VCPU," isn't it?

> if (from_vmentry &&
> (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS)) {
> kvm_set_dr(vcpu, 7, vmcs12->guest_dr7);
> --
> 2.7.4
>