[PATCH v9 13/17] KVM: nVMX: Add necessary Arch LBR settings for nested VM

Yang Weijiang
2022-02-16T10:28:02Z

Arch LBR is not supported in nested VM now. This patch is to add
necessary settings to make it pass host KVM checks before L2 VM is
launched and also to avoid some warnings reported from L1.

Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
arch/x86/kvm/vmx/nested.c | 7 +++++--
arch/x86/kvm/vmx/pmu_intel.c | 2 ++
arch/x86/kvm/vmx/vmcs12.c | 1 +
arch/x86/kvm/vmx/vmcs12.h | 3 ++-
4 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index ba34e94049c7..cdc9d33bb47c 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -6552,7 +6552,9 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps)
VM_EXIT_HOST_ADDR_SPACE_SIZE |
#endif
VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT |
- VM_EXIT_CLEAR_BNDCFGS | VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL;
+ VM_EXIT_CLEAR_BNDCFGS | VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL |
+ VM_EXIT_CLEAR_IA32_LBR_CTL;
+
msrs->exit_ctls_high |=
VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR |
VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER |
@@ -6572,7 +6574,8 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps)
VM_ENTRY_IA32E_MODE |
#endif
VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_LOAD_BNDCFGS |
- VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
+ VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL | VM_ENTRY_LOAD_IA32_LBR_CTL;
+
msrs->entry_ctls_high |=
(VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR | VM_ENTRY_LOAD_IA32_EFER);

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 3f1ffc928e36..e2cae30614b1 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -228,6 +228,8 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
break;
case MSR_ARCH_LBR_DEPTH:
case MSR_ARCH_LBR_CTL:
+ if (is_guest_mode(vcpu))
+ break;
if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR))
ret = guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR);
break;
diff --git a/arch/x86/kvm/vmx/vmcs12.c b/arch/x86/kvm/vmx/vmcs12.c
index 2251b60920f8..bcda664e4d26 100644
--- a/arch/x86/kvm/vmx/vmcs12.c
+++ b/arch/x86/kvm/vmx/vmcs12.c
@@ -65,6 +65,7 @@ const unsigned short vmcs12_field_offsets[] = {
FIELD64(HOST_IA32_PAT, host_ia32_pat),
FIELD64(HOST_IA32_EFER, host_ia32_efer),
FIELD64(HOST_IA32_PERF_GLOBAL_CTRL, host_ia32_perf_global_ctrl),
+ FIELD64(GUEST_IA32_LBR_CTL, guest_lbr_ctl),
FIELD(PIN_BASED_VM_EXEC_CONTROL, pin_based_vm_exec_control),
FIELD(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control),
FIELD(EXCEPTION_BITMAP, exception_bitmap),
diff --git a/arch/x86/kvm/vmx/vmcs12.h b/arch/x86/kvm/vmx/vmcs12.h
index 746129ddd5ae..bf50227fe401 100644
--- a/arch/x86/kvm/vmx/vmcs12.h
+++ b/arch/x86/kvm/vmx/vmcs12.h
@@ -71,7 +71,7 @@ struct __packed vmcs12 {
u64 pml_address;
u64 encls_exiting_bitmap;
u64 tsc_multiplier;
- u64 padding64[1]; /* room for future expansion */
+ u64 guest_lbr_ctl;
/*
* To allow migration of L1 (complete with its L2 guests) between
* machines of different natural widths (32 or 64 bit), we cannot have
@@ -254,6 +254,7 @@ static inline void vmx_check_vmcs12_offsets(void)
CHECK_OFFSET(pml_address, 312);
CHECK_OFFSET(encls_exiting_bitmap, 320);
CHECK_OFFSET(tsc_multiplier, 328);
+ CHECK_OFFSET(guest_lbr_ctl, 336);
CHECK_OFFSET(cr0_guest_host_mask, 344);
CHECK_OFFSET(cr4_guest_host_mask, 352);
CHECK_OFFSET(cr0_read_shadow, 360);
--
2.27.0