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

Xin Li
2023-11-08T19:00:29Z

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@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
---
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);
}

static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
--
2.42.0