[PATCH v2 20/25] KVM: nVMX: Add support for VMX FRED controls

From: Xin Li
Date: Wed Feb 07 2024 - 13:06:43 EST


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.

Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 14 ++++++++++----
arch/x86/kvm/vmx/vmx.c | 1 +
2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index f9c1fbeac302..04a9cdb0361f 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1239,10 +1239,12 @@ 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)
{
@@ -6988,7 +6990,8 @@ 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);
@@ -7147,6 +7150,9 @@ static void nested_vmx_setup_basic(struct nested_vmx_msrs *msrs)

if (cpu_has_vmx_basic_inout())
msrs->basic |= VMX_BASIC_INOUT;
+
+ if (kvm_cpu_cap_has(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 fc808d599493..1005b6a57d23 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7915,6 +7915,7 @@ static void nested_vmx_cr_fixed1_bits_update(struct kvm_vcpu *vcpu)

entry = kvm_find_cpuid_entry_index(vcpu, 0x7, 1);
cr4_fixed1_update(X86_CR4_LAM_SUP, eax, feature_bit(LAM));
+ cr4_fixed1_update(X86_CR4_FRED, eax, feature_bit(FRED));

#undef cr4_fixed1_update
}
--
2.43.0