This was tested by booting L1,L2,L3 (all Linux) and checking that no VMLOAD/VMSAVE vmexits happened.
Signed-off-by: Maxim Levitsky mlevitsk@redhat.com --- arch/x86/kvm/svm/nested.c | 35 +++++++++++++++++++++++++++++------ arch/x86/kvm/svm/svm.c | 7 +++++++ arch/x86/kvm/svm/svm.h | 8 +++++++- 3 files changed, 43 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index eca0f2f41bf30..2dc97cca68f7c 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -119,6 +119,20 @@ static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu) vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; }
+static bool nested_vmcb_needs_vls_intercept(struct vcpu_svm *svm) +{ + if (!svm->v_vmload_vmsave_enabled) + return true; + + if (!nested_npt_enabled(svm)) + return true; + + if (!(svm->nested.ctl.virt_ext & VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK)) + return true; + + return false; +} + void recalc_intercepts(struct vcpu_svm *svm) { struct vmcb_control_area *c, *h, *g; @@ -159,8 +173,17 @@ void recalc_intercepts(struct vcpu_svm *svm) if (!intercept_smi) vmcb_clr_intercept(c, INTERCEPT_SMI);
- vmcb_set_intercept(c, INTERCEPT_VMLOAD); - vmcb_set_intercept(c, INTERCEPT_VMSAVE); + if (nested_vmcb_needs_vls_intercept(svm)) { + /* + * If the virtual VMLOAD/VMSAVE is not enabled for the L2, + * we must intercept these instructions to correctly + * emulate them in case L1 doesn't intercept them. + */ + vmcb_set_intercept(c, INTERCEPT_VMLOAD); + vmcb_set_intercept(c, INTERCEPT_VMSAVE); + } else { + WARN_ON(!(c->virt_ext & VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK)); + } }
static void copy_vmcb_control_area(struct vmcb_control_area *dst, @@ -402,10 +425,7 @@ static void nested_save_pending_event_to_vmcb12(struct vcpu_svm *svm, vmcb12->control.exit_int_info = exit_int_info; }
-static inline bool nested_npt_enabled(struct vcpu_svm *svm) -{ - return svm->nested.ctl.nested_ctl & SVM_NESTED_CTL_NP_ENABLE; -} +
static void nested_svm_transition_tlb_flush(struct kvm_vcpu *vcpu) { @@ -594,6 +614,9 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm) svm->vmcb->control.virt_ext |= (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK);
+ if (!nested_vmcb_needs_vls_intercept(svm)) + svm->vmcb->control.virt_ext |= VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK; + nested_svm_transition_tlb_flush(vcpu);
/* Enter Guest-Mode */ diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 0ae8fa9400902..77fd0922c4060 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1023,6 +1023,9 @@ static __init void svm_set_cpu_caps(void) if (lbrv) kvm_cpu_cap_set(X86_FEATURE_LBRV);
+ if (vls) + kvm_cpu_cap_set(X86_FEATURE_V_VMSAVE_VMLOAD); + /* Nested VM can receive #VMEXIT instead of triggering #GP */ kvm_cpu_cap_set(X86_FEATURE_SVME_ADDR_CHK); } @@ -1274,6 +1277,8 @@ static inline void init_vmcb_after_set_cpuid(struct kvm_vcpu *vcpu)
set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SYSENTER_EIP, 0, 0); set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SYSENTER_ESP, 0, 0); + + svm->v_vmload_vmsave_enabled = false; } else { /* * If hardware supports Virtual VMLOAD VMSAVE then enable it @@ -4156,6 +4161,8 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) svm->tsc_scaling_enabled = tsc_scaling && guest_cpuid_has(vcpu, X86_FEATURE_TSCRATEMSR); svm->lbrv_enabled = lbrv && guest_cpuid_has(vcpu, X86_FEATURE_LBRV);
+ svm->v_vmload_vmsave_enabled = vls && guest_cpuid_has(vcpu, X86_FEATURE_V_VMSAVE_VMLOAD); + svm_recalc_instruction_intercepts(vcpu, svm);
/* For sev guests, the memory encryption bit is not reserved in CR3. */ diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index c3d46fdf4b9ad..ec8dd09e41e69 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -161,10 +161,11 @@ struct vcpu_svm { unsigned int3_injected; unsigned long int3_rip;
- /* cached guest cpuid flags for faster access */ + /* optional nested SVM features that are enabled for this guest */ bool nrips_enabled : 1; bool tsc_scaling_enabled : 1; bool lbrv_enabled : 1; + bool v_vmload_vmsave_enabled : 1;
u32 ldr_reg; u32 dfr_reg; @@ -412,6 +413,11 @@ static inline bool gif_set(struct vcpu_svm *svm) return !!(svm->vcpu.arch.hflags & HF_GIF_MASK); }
+static inline bool nested_npt_enabled(struct vcpu_svm *svm) +{ + return svm->nested.ctl.nested_ctl & SVM_NESTED_CTL_NP_ENABLE; +} + /* svm.c */ #define MSR_INVALID 0xffffffffU