[PATCH v1 17/23] KVM: nVMX: Add support for VMX FRED controls

Xin Li
2023-11-08T19:00:32Z

Add VMX FRED controls to nested VMX controls and set the VMX
nested-exception support bit (bit 58) in the nested IA32_VMX_BASIC MSR
when FRED is enabled.

Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
---
arch/x86/kvm/vmx/hyperv.c | 7 +++++--
arch/x86/kvm/vmx/nested.c | 14 ++++++++++----
arch/x86/kvm/vmx/vmx.c | 3 +++
3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/vmx/hyperv.c b/arch/x86/kvm/vmx/hyperv.c
index b12ef8fd76c9..28fca62f3887 100644
--- a/arch/x86/kvm/vmx/hyperv.c
+++ b/arch/x86/kvm/vmx/hyperv.c
@@ -106,7 +106,9 @@
VM_EXIT_CLEAR_IA32_RTIT_CTL | \
VM_EXIT_ACTIVATE_SECONDARY_CONTROLS)

-#define EVMCS1_SUPPORTED_VMEXIT_CTRL2 (0ULL)
+#define EVMCS1_SUPPORTED_VMEXIT_CTRL2 \
+ (SECONDARY_VM_EXIT_SAVE_IA32_FRED | \
+ SECONDARY_VM_EXIT_LOAD_IA32_FRED)

#define EVMCS1_SUPPORTED_VMENTRY_CTRL \
(VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR | \
@@ -117,7 +119,8 @@
VM_ENTRY_LOAD_IA32_EFER | \
VM_ENTRY_LOAD_BNDCFGS | \
VM_ENTRY_PT_CONCEAL_PIP | \
- VM_ENTRY_LOAD_IA32_RTIT_CTL)
+ VM_ENTRY_LOAD_IA32_RTIT_CTL | \
+ VM_ENTRY_LOAD_IA32_FRED)

#define EVMCS1_SUPPORTED_VMFUNC (0)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index af616c4a3491..b85cd5c0ec98 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1230,10 +1230,12 @@ static bool is_bitwise_subset(u64 superset, u64 subset, u64 mask)
#define VMX_BASIC_FEATURES_MASK \
(VMX_BASIC_DUAL_MONITOR_TREATMENT | \
VMX_BASIC_INOUT | \
- VMX_BASIC_TRUE_CTLS)
+ VMX_BASIC_TRUE_CTLS | \
+ VMX_BASIC_NESTED_EXCEPTION)

-#define VMX_BASIC_RESERVED_BITS \
- (GENMASK_ULL(63, 56) | GENMASK_ULL(47, 45) | BIT_ULL(31))
+#define VMX_BASIC_RESERVED_BITS \
+ (GENMASK_ULL(63, 59) | GENMASK_ULL(57, 56) | \
+ GENMASK_ULL(47, 45) | BIT_ULL(31))

static int vmx_restore_vmx_basic(struct vcpu_vmx *vmx, u64 data)
{
@@ -6985,7 +6987,8 @@ static void nested_vmx_setup_entry_ctls(struct vmcs_config *vmcs_conf,
#ifdef CONFIG_X86_64
VM_ENTRY_IA32E_MODE |
#endif
- VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_LOAD_BNDCFGS;
+ VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_LOAD_BNDCFGS |
+ VM_ENTRY_LOAD_IA32_FRED;
msrs->entry_ctls_high |=
(VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR | VM_ENTRY_LOAD_IA32_EFER |
VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL);
@@ -7141,6 +7144,9 @@ static void nested_vmx_setup_basic(struct nested_vmx_msrs *msrs)

if (cpu_has_vmx_basic_inout())
msrs->basic |= VMX_BASIC_INOUT;
+
+ if (cpu_feature_enabled(X86_FEATURE_FRED))
+ msrs->basic |= VMX_BASIC_NESTED_EXCEPTION;
}

static void nested_vmx_setup_cr_fixed(struct nested_vmx_msrs *msrs)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b826dc188fc7..3353fd6615a2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7970,6 +7970,9 @@ 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));

+ entry = kvm_find_cpuid_entry_index(vcpu, 0x7, 1);
+ cr4_fixed1_update(X86_CR4_FRED, eax, feature_bit(FRED));
+
#undef cr4_fixed1_update
}

--
2.42.0