linux-kernel - [PATCH v2 26/28] KVM: nVMX: Use sanitized required-1 bits for VMX control MSRs

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Date:   Wed, 29 Jun 2022 17:06:23 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>
Cc:     Anirudh Rayabharam <anrayabh@...ux.microsoft.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 26/28] KVM: nVMX: Use sanitized required-1 bits for VMX control MSRs

vmcs_config has the required information for setting up required-1 bits of
nested VMCS control MSRs, use it to avoid redundant rdmsr()s.

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 arch/x86/kvm/vmx/nested.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index e5b19b5e6cab..8af56be48a43 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -6569,9 +6569,6 @@ void nested_vmx_setup_ctls_msrs(struct vmcs_config *vmcs_conf, u32 ept_caps)
 {
 	struct nested_vmx_msrs *msrs = &vmcs_conf->nested;
 
-	/* Take the allowed-1 bits from KVM's sanitized VMCS configuration. */
-	u32 ignore_high;
-
 	/*
 	 * Note that as a general rule, the high half of the MSRs (bits in
 	 * the control fields which may be 1) should be initialized by the
@@ -6588,8 +6585,7 @@ void nested_vmx_setup_ctls_msrs(struct vmcs_config *vmcs_conf, u32 ept_caps)
 	 */
 
 	/* pin-based controls */
-	rdmsr(MSR_IA32_VMX_PINBASED_CTLS, msrs->pinbased_ctls_low, ignore_high);
-	msrs->pinbased_ctls_low |=
+	msrs->pinbased_ctls_low = vmcs_conf->pin_based_exec_ctrl_req1 |
 		PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 
 	msrs->pinbased_ctls_high = vmcs_conf->pin_based_exec_ctrl;
-- 
2.35.3