Clear FRED VM entry/exit controls when initializing a vCPU, and set these controls only if FRED is enumerated after set CPUID.
FRED VM entry/exit controls need to be set to establish context sufficient to support FRED event delivery immediately after VM entry and exit. However it is not required to save/load FRED MSRs for a non-FRED guest, which aren't supposed to access FRED MSRs.
Signed-off-by: Xin Li xin3.li@intel.com Tested-by: Shan Kang shan.kang@intel.com ---
Changes since v1: * Use kvm_cpu_cap_has() instead of cpu_feature_enabled() (Chao Gao). * Clear FRED VM entry/exit controls if FRED is not enumerated (Chao Gao). * Use guest_can_use() to trace FRED enumeration in a vcpu (Chao Gao). --- arch/x86/kvm/governed_features.h | 1 + arch/x86/kvm/vmx/vmx.c | 32 +++++++++++++++++++++++++++++++- 2 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h index ad463b1ed4e4..507ca73e52e9 100644 --- a/arch/x86/kvm/governed_features.h +++ b/arch/x86/kvm/governed_features.h @@ -17,6 +17,7 @@ KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD) KVM_GOVERNED_X86_FEATURE(VGIF) KVM_GOVERNED_X86_FEATURE(VNMI) KVM_GOVERNED_X86_FEATURE(LAM) +KVM_GOVERNED_X86_FEATURE(FRED)
#undef KVM_GOVERNED_X86_FEATURE #undef KVM_GOVERNED_FEATURE diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 4023474ea002..34b6676f60d8 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4402,6 +4402,9 @@ static u32 vmx_vmentry_ctrl(void) if (cpu_has_perf_global_ctrl_bug()) vmentry_ctrl &= ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
+ /* Whether to load guest FRED MSRs is deferred until after set CPUID */ + vmentry_ctrl &= ~VM_ENTRY_LOAD_IA32_FRED; + return vmentry_ctrl; }
@@ -4430,7 +4433,13 @@ static u32 vmx_vmexit_ctrl(void)
static u64 vmx_secondary_vmexit_ctrl(void) { - return vmcs_config.secondary_vmexit_ctrl; + u64 secondary_vmexit_ctrl = vmcs_config.secondary_vmexit_ctrl; + + /* Whether to save/load FRED MSRs is deferred until after set CPUID */ + secondary_vmexit_ctrl &= ~(SECONDARY_VM_EXIT_SAVE_IA32_FRED | + SECONDARY_VM_EXIT_LOAD_IA32_FRED); + + return secondary_vmexit_ctrl; }
static void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) @@ -7762,10 +7771,31 @@ static void update_intel_pt_cfg(struct kvm_vcpu *vcpu) vmx->pt_desc.ctl_bitmask &= ~(0xfULL << (32 + i * 4)); }
+static void vmx_vcpu_config_fred_after_set_cpuid(struct kvm_vcpu *vcpu) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + + kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_FRED); + + if (guest_can_use(vcpu, X86_FEATURE_FRED)) { + vm_entry_controls_setbit(vmx, VM_ENTRY_LOAD_IA32_FRED); + secondary_vm_exit_controls_setbit(vmx, + SECONDARY_VM_EXIT_SAVE_IA32_FRED | + SECONDARY_VM_EXIT_LOAD_IA32_FRED); + } else { + vm_entry_controls_clearbit(vmx, VM_ENTRY_LOAD_IA32_FRED); + secondary_vm_exit_controls_clearbit(vmx, + SECONDARY_VM_EXIT_SAVE_IA32_FRED | + SECONDARY_VM_EXIT_LOAD_IA32_FRED); + } +} + static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu);
+ vmx_vcpu_config_fred_after_set_cpuid(vcpu); + /* * XSAVES is effectively enabled if and only if XSAVE is also exposed * to the guest. XSAVES depends on CR4.OSXSAVE, and CR4.OSXSAVE can be