* [PATCH v6 1/3] KVM: nVMX: Sync L2 guest CET states between L1/L2
2021-04-21 9:05 [PATCH v6 0/3] CET fix patches for nested guest Yang Weijiang
@ 2021-04-21 9:05 ` Yang Weijiang
2021-04-21 9:05 ` [PATCH v6 2/3] KVM: nVMX: Set X86_CR4_CET in cr4_fixed1_bits if CET IBT is enabled Yang Weijiang
2021-04-21 9:05 ` [PATCH v6 3/3] KVM: nVMX: Add CET entry/exit load bits to evmcs unsupported list Yang Weijiang
2 siblings, 0 replies; 4+ messages in thread
From: Yang Weijiang @ 2021-04-21 9:05 UTC (permalink / raw)
To: pbonzini, seanjc, kvm, linux-kernel; +Cc: Yang Weijiang
These fields are rarely updated by L1 QEMU/KVM, sync them when L1 is trying to
read/write them and after they're changed. If CET guest entry-load bit is not
set by L1 guest, migrate them to L2 manaully.
Opportunistically remove one blank line in previous patch.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
arch/x86/kvm/cpuid.c | 1 -
arch/x86/kvm/vmx/nested.c | 31 +++++++++++++++++++++++++++++++
arch/x86/kvm/vmx/vmx.h | 3 +++
3 files changed, 34 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index d191de769093..8692f53b8cd0 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -143,7 +143,6 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
}
vcpu->arch.guest_supported_xss =
(((u64)best->edx << 32) | best->ecx) & supported_xss;
-
} else {
vcpu->arch.guest_supported_xss = 0;
}
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 9728efd529a1..db78a62ef4c3 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2516,6 +2516,13 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);
set_cr4_guest_host_mask(vmx);
+
+ if (kvm_cet_supported() && vmx->nested.nested_run_pending &&
+ (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_CET_STATE)) {
+ vmcs_writel(GUEST_SSP, vmcs12->guest_ssp);
+ vmcs_writel(GUEST_S_CET, vmcs12->guest_s_cet);
+ vmcs_writel(GUEST_INTR_SSP_TABLE, vmcs12->guest_ssp_tbl);
+ }
}
/*
@@ -2556,6 +2563,15 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
if (kvm_mpx_supported() && (!vmx->nested.nested_run_pending ||
!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)))
vmcs_write64(GUEST_BNDCFGS, vmx->nested.vmcs01_guest_bndcfgs);
+
+ if (kvm_cet_supported() && (!vmx->nested.nested_run_pending ||
+ !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_CET_STATE))) {
+ vmcs_writel(GUEST_SSP, vmx->nested.vmcs01_guest_ssp);
+ vmcs_writel(GUEST_S_CET, vmx->nested.vmcs01_guest_s_cet);
+ vmcs_writel(GUEST_INTR_SSP_TABLE,
+ vmx->nested.vmcs01_guest_ssp_tbl);
+ }
+
vmx_set_rflags(vcpu, vmcs12->guest_rflags);
/* EXCEPTION_BITMAP and CR0_GUEST_HOST_MASK should basically be the
@@ -3375,6 +3391,12 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
if (kvm_mpx_supported() &&
!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
vmx->nested.vmcs01_guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);
+ if (kvm_cet_supported() && (!vmx->nested.nested_run_pending ||
+ !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_CET_STATE))) {
+ vmx->nested.vmcs01_guest_ssp = vmcs_readl(GUEST_SSP);
+ vmx->nested.vmcs01_guest_s_cet = vmcs_readl(GUEST_S_CET);
+ vmx->nested.vmcs01_guest_ssp_tbl = vmcs_readl(GUEST_INTR_SSP_TABLE);
+ }
/*
* Overwrite vmcs01.GUEST_CR3 with L1's CR3 if EPT is disabled *and*
@@ -4001,6 +4023,9 @@ static bool is_vmcs12_ext_field(unsigned long field)
case GUEST_IDTR_BASE:
case GUEST_PENDING_DBG_EXCEPTIONS:
case GUEST_BNDCFGS:
+ case GUEST_SSP:
+ case GUEST_INTR_SSP_TABLE:
+ case GUEST_S_CET:
return true;
default:
break;
@@ -4052,6 +4077,12 @@ static void sync_vmcs02_to_vmcs12_rare(struct kvm_vcpu *vcpu,
vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS);
if (kvm_mpx_supported())
vmcs12->guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);
+ if (kvm_cet_supported() && (guest_cpuid_has(vcpu, X86_FEATURE_SHSTK) ||
+ guest_cpuid_has(vcpu, X86_FEATURE_IBT))) {
+ vmcs12->guest_ssp = vmcs_readl(GUEST_SSP);
+ vmcs12->guest_s_cet = vmcs_readl(GUEST_S_CET);
+ vmcs12->guest_ssp_tbl = vmcs_readl(GUEST_INTR_SSP_TABLE);
+ }
vmx->nested.need_sync_vmcs02_to_vmcs12_rare = false;
}
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 9d3a557949ac..36dc4fdb0909 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -155,6 +155,9 @@ struct nested_vmx {
/* to migrate it to L2 if VM_ENTRY_LOAD_DEBUG_CONTROLS is off */
u64 vmcs01_debugctl;
u64 vmcs01_guest_bndcfgs;
+ u64 vmcs01_guest_ssp;
+ u64 vmcs01_guest_s_cet;
+ u64 vmcs01_guest_ssp_tbl;
/* to migrate it to L1 if L2 writes to L1's CR8 directly */
int l1_tpr_threshold;
--
2.26.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v6 2/3] KVM: nVMX: Set X86_CR4_CET in cr4_fixed1_bits if CET IBT is enabled
2021-04-21 9:05 [PATCH v6 0/3] CET fix patches for nested guest Yang Weijiang
2021-04-21 9:05 ` [PATCH v6 1/3] KVM: nVMX: Sync L2 guest CET states between L1/L2 Yang Weijiang
@ 2021-04-21 9:05 ` Yang Weijiang
2021-04-21 9:05 ` [PATCH v6 3/3] KVM: nVMX: Add CET entry/exit load bits to evmcs unsupported list Yang Weijiang
2 siblings, 0 replies; 4+ messages in thread
From: Yang Weijiang @ 2021-04-21 9:05 UTC (permalink / raw)
To: pbonzini, seanjc, kvm, linux-kernel; +Cc: Yang Weijiang
CET SHSTK and IBT are independently controlled by kernel, set X86_CR4_CET
bit in cr4_fixed1_bits if either of them is enabled so that nested guest
can enjoy the feature.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
arch/x86/kvm/vmx/vmx.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e78650bf8ae8..bd89b5a24c38 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7267,6 +7267,7 @@ static void nested_vmx_cr_fixed1_bits_update(struct kvm_vcpu *vcpu)
cr4_fixed1_update(X86_CR4_UMIP, ecx, feature_bit(UMIP));
cr4_fixed1_update(X86_CR4_LA57, ecx, feature_bit(LA57));
cr4_fixed1_update(X86_CR4_CET, ecx, feature_bit(SHSTK));
+ cr4_fixed1_update(X86_CR4_CET, edx, feature_bit(IBT));
#undef cr4_fixed1_update
}
--
2.26.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v6 3/3] KVM: nVMX: Add CET entry/exit load bits to evmcs unsupported list
2021-04-21 9:05 [PATCH v6 0/3] CET fix patches for nested guest Yang Weijiang
2021-04-21 9:05 ` [PATCH v6 1/3] KVM: nVMX: Sync L2 guest CET states between L1/L2 Yang Weijiang
2021-04-21 9:05 ` [PATCH v6 2/3] KVM: nVMX: Set X86_CR4_CET in cr4_fixed1_bits if CET IBT is enabled Yang Weijiang
@ 2021-04-21 9:05 ` Yang Weijiang
2 siblings, 0 replies; 4+ messages in thread
From: Yang Weijiang @ 2021-04-21 9:05 UTC (permalink / raw)
To: pbonzini, seanjc, kvm, linux-kernel; +Cc: Yang Weijiang
Nested guest doesn't support CET when KVM is running as an intermediate
layer between two Hyper-Vs for now, so mask out related CET entry/exit
load bits. Relevant enabling patches will be posted as a separate patch
series.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
arch/x86/kvm/vmx/evmcs.c | 4 ++--
arch/x86/kvm/vmx/evmcs.h | 6 ++++--
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index 41f24661af04..9f81db51fd8b 100644
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -351,11 +351,11 @@ void nested_evmcs_filter_control_msr(u32 msr_index, u64 *pdata)
switch (msr_index) {
case MSR_IA32_VMX_EXIT_CTLS:
case MSR_IA32_VMX_TRUE_EXIT_CTLS:
- ctl_high &= ~VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL;
+ ctl_high &= ~EVMCS1_UNSUPPORTED_VMEXIT_CTRL;
break;
case MSR_IA32_VMX_ENTRY_CTLS:
case MSR_IA32_VMX_TRUE_ENTRY_CTLS:
- ctl_high &= ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
+ ctl_high &= ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL;
break;
case MSR_IA32_VMX_PROCBASED_CTLS2:
ctl_high &= ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
index bd41d9462355..25588694eb04 100644
--- a/arch/x86/kvm/vmx/evmcs.h
+++ b/arch/x86/kvm/vmx/evmcs.h
@@ -59,8 +59,10 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs);
SECONDARY_EXEC_SHADOW_VMCS | \
SECONDARY_EXEC_TSC_SCALING | \
SECONDARY_EXEC_PAUSE_LOOP_EXITING)
-#define EVMCS1_UNSUPPORTED_VMEXIT_CTRL (VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
-#define EVMCS1_UNSUPPORTED_VMENTRY_CTRL (VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL)
+#define EVMCS1_UNSUPPORTED_VMEXIT_CTRL (VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL | \
+ VM_EXIT_LOAD_CET_STATE)
+#define EVMCS1_UNSUPPORTED_VMENTRY_CTRL (VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL | \
+ VM_ENTRY_LOAD_CET_STATE)
#define EVMCS1_UNSUPPORTED_VMFUNC (VMX_VMFUNC_EPTP_SWITCHING)
#if IS_ENABLED(CONFIG_HYPERV)
--
2.26.2
^ permalink raw reply related [flat|nested] 4+ messages in thread