Re: [PATCH v1 07/23] KVM: VMX: Disable intercepting FRED MSRs

[Chao Gao]

On Wed, Nov 08, 2023 at 10:29:47AM -0800, Xin Li wrote:
>Add FRED MSRs to the valid passthrough MSR list and disable intercepting
>FRED MSRs only if FRED is enumerated after set CPUID.
>
>Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
>Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
>---
> arch/x86/kvm/vmx/vmx.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
>diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
>index 5d4786812664..327e052d90c1 100644
>--- a/arch/x86/kvm/vmx/vmx.c
>+++ b/arch/x86/kvm/vmx/vmx.c
>@@ -700,6 +700,9 @@ 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;
>@@ -7813,6 +7816,16 @@ static void vmx_vcpu_config_fred_after_set_cpuid(struct kvm_vcpu *vcpu)
> 	secondary_vm_exit_controls_setbit(vmx,
> 					  SECONDARY_VM_EXIT_SAVE_IA32_FRED |
> 					  SECONDARY_VM_EXIT_LOAD_IA32_FRED);
>+
>+	vmx_disable_intercept_for_msr(vcpu, MSR_IA32_FRED_RSP0, MSR_TYPE_RW);
>+	vmx_disable_intercept_for_msr(vcpu, MSR_IA32_FRED_RSP1, MSR_TYPE_RW);
>+	vmx_disable_intercept_for_msr(vcpu, MSR_IA32_FRED_RSP2, MSR_TYPE_RW);
>+	vmx_disable_intercept_for_msr(vcpu, MSR_IA32_FRED_RSP3, MSR_TYPE_RW);
>+	vmx_disable_intercept_for_msr(vcpu, MSR_IA32_FRED_STKLVLS, MSR_TYPE_RW);
>+	vmx_disable_intercept_for_msr(vcpu, MSR_IA32_FRED_SSP1, MSR_TYPE_RW);
>+	vmx_disable_intercept_for_msr(vcpu, MSR_IA32_FRED_SSP2, MSR_TYPE_RW);
>+	vmx_disable_intercept_for_msr(vcpu, MSR_IA32_FRED_SSP3, MSR_TYPE_RW);
>+	vmx_disable_intercept_for_msr(vcpu, MSR_IA32_FRED_CONFIG, MSR_TYPE_RW);

this has the same issue as patch 6.