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[v3,25/25] KVM: nVMX: Use cached host MSR_IA32_VMX_MISC value for setting up nested MSR

Message ID 20220708144223.610080-26-vkuznets@redhat.com (mailing list archive)
State New, archived
Headers show
Series KVM: VMX: Support updated eVMCSv1 revision + use vmcs_config for L1 VMX MSRs | expand

Commit Message

Vitaly Kuznetsov July 8, 2022, 2:42 p.m. UTC 
vmcs_config has cased host MSR_IA32_VMX_MISC value, use it for setting
up nested MSR_IA32_VMX_MISC in nested_vmx_setup_ctls_msrs() and avoid the
redundant rdmsr().

No (real) functional change intended.

Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/vmx/nested.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

Comments

Maxim Levitsky July 12, 2022, 12:11 p.m. UTC | #1 
On Fri, 2022-07-08 at 16:42 +0200, Vitaly Kuznetsov wrote:
> vmcs_config has cased host MSR_IA32_VMX_MISC value, use it for setting
 ^^ typo
> up nested MSR_IA32_VMX_MISC in nested_vmx_setup_ctls_msrs() and avoid the
> redundant rdmsr().
> 
> No (real) functional change intended.
> 
> Reviewed-by: Jim Mattson <jmattson@google.com>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  arch/x86/kvm/vmx/nested.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index 3d386c663fac..8026dab71086 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -6754,10 +6754,7 @@ void nested_vmx_setup_ctls_msrs(struct vmcs_config *vmcs_conf, u32 ept_caps)
>                 msrs->secondary_ctls_high |= SECONDARY_EXEC_ENCLS_EXITING;
>  
>         /* miscellaneous data */
> -       rdmsr(MSR_IA32_VMX_MISC,
> -               msrs->misc_low,
> -               msrs->misc_high);
> -       msrs->misc_low &= VMX_MISC_SAVE_EFER_LMA;
> +       msrs->misc_low = (u32)vmcs_conf->misc & VMX_MISC_SAVE_EFER_LMA;
>         msrs->misc_low |=
>                 MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS |
>                 VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE |

Besides the typo,
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>

Best regards,
 Maxim Levitsky
diff mbox series

Patch

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 3d386c663fac..8026dab71086 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -6754,10 +6754,7 @@  void nested_vmx_setup_ctls_msrs(struct vmcs_config *vmcs_conf, u32 ept_caps)
 		msrs->secondary_ctls_high |= SECONDARY_EXEC_ENCLS_EXITING;
 
 	/* miscellaneous data */
-	rdmsr(MSR_IA32_VMX_MISC,
-		msrs->misc_low,
-		msrs->misc_high);
-	msrs->misc_low &= VMX_MISC_SAVE_EFER_LMA;
+	msrs->misc_low = (u32)vmcs_conf->misc & VMX_MISC_SAVE_EFER_LMA;
 	msrs->misc_low |=
 		MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS |
 		VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE |