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From: Xin Li <xin3.li@intel.com>
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Subject: [PATCH v2 07/25] KVM: VMX: Set intercept for FRED MSRs
Date: Wed,  7 Feb 2024 09:26:27 -0800
Message-ID: <20240207172646.3981-8-xin3.li@intel.com>
In-Reply-To: <20240207172646.3981-1-xin3.li@intel.com>
References: <20240207172646.3981-1-xin3.li@intel.com>
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Add FRED MSRs to the valid passthrough MSR list and set FRED MSRs intercept
based on FRED enumeration.

Signed-off-by: Xin Li <xin3.li@intel.com>
Tested-by: Shan Kang <shan.kang@intel.com>
---

Change since v1:
* Enable FRED MSRs intercept if FRED is no longer enumerated in CPUID
  (Chao Gao).
---
 arch/x86/kvm/vmx/vmx.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 34b6676f60d8..d58ed2d3d379 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -693,6 +693,9 @@ static bool is_valid_passthrough_msr(u32 msr)
 	case MSR_LBR_CORE_TO ... MSR_LBR_CORE_TO + 8:
 		/* LBR MSRs. These are handled in vmx_update_intercept_for_lbr_msrs() */
 		return true;
+	case MSR_IA32_FRED_RSP0 ... MSR_IA32_FRED_CONFIG:
+		/* FRED MSRs should be passthrough to FRED guests only */
+		return true;
 	}
 
 	r = possible_passthrough_msr_slot(msr) != -ENOENT;
@@ -7774,10 +7777,12 @@ static void update_intel_pt_cfg(struct kvm_vcpu *vcpu)
 static void vmx_vcpu_config_fred_after_set_cpuid(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	bool fred_enumerated;
 
 	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_FRED);
+	fred_enumerated = guest_can_use(vcpu, X86_FEATURE_FRED);
 
-	if (guest_can_use(vcpu, X86_FEATURE_FRED)) {
+	if (fred_enumerated) {
 		vm_entry_controls_setbit(vmx, VM_ENTRY_LOAD_IA32_FRED);
 		secondary_vm_exit_controls_setbit(vmx,
 						  SECONDARY_VM_EXIT_SAVE_IA32_FRED |
@@ -7788,6 +7793,16 @@ static void vmx_vcpu_config_fred_after_set_cpuid(struct kvm_vcpu *vcpu)
 						    SECONDARY_VM_EXIT_SAVE_IA32_FRED |
 						    SECONDARY_VM_EXIT_LOAD_IA32_FRED);
 	}
+
+	vmx_set_intercept_for_msr(vcpu, MSR_IA32_FRED_RSP0, MSR_TYPE_RW, !fred_enumerated);
+	vmx_set_intercept_for_msr(vcpu, MSR_IA32_FRED_RSP1, MSR_TYPE_RW, !fred_enumerated);
+	vmx_set_intercept_for_msr(vcpu, MSR_IA32_FRED_RSP2, MSR_TYPE_RW, !fred_enumerated);
+	vmx_set_intercept_for_msr(vcpu, MSR_IA32_FRED_RSP3, MSR_TYPE_RW, !fred_enumerated);
+	vmx_set_intercept_for_msr(vcpu, MSR_IA32_FRED_STKLVLS, MSR_TYPE_RW, !fred_enumerated);
+	vmx_set_intercept_for_msr(vcpu, MSR_IA32_FRED_SSP1, MSR_TYPE_RW, !fred_enumerated);
+	vmx_set_intercept_for_msr(vcpu, MSR_IA32_FRED_SSP2, MSR_TYPE_RW, !fred_enumerated);
+	vmx_set_intercept_for_msr(vcpu, MSR_IA32_FRED_SSP3, MSR_TYPE_RW, !fred_enumerated);
+	vmx_set_intercept_for_msr(vcpu, MSR_IA32_FRED_CONFIG, MSR_TYPE_RW, !fred_enumerated);
 }
 
 static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
-- 
2.43.0