[RFC PATCH v6 28/36] KVM: VMX: Add missing VMEXIT controls to vmcs_config

Sean Christopherson
2022-08-24T03:04:46Z

As a preparation to reusing the result of setup_vmcs_config() in
nested VMX MSR setup, add the VMEXIT controls which KVM doesn't
use but supports for nVMX to KVM_OPT_VMX_VM_EXIT_CONTROLS and
filter them out in vmx_vmexit_ctrl().

No functional change intended.

Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/vmx/vmx.c | 7 +++++++
arch/x86/kvm/vmx/vmx.h | 3 +++
2 files changed, 10 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 23e237ad3956..079cc4835248 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4275,6 +4275,13 @@ static u32 vmx_vmexit_ctrl(void)
{
u32 vmexit_ctrl = vmcs_config.vmexit_ctrl;

+ /*
+ * Not used by KVM and never set in vmcs01 or vmcs02, but emulated for
+ * nested virtualization and thus allowed to be set in vmcs12.
+ */
+ vmexit_ctrl &= ~(VM_EXIT_SAVE_IA32_PAT | VM_EXIT_SAVE_IA32_EFER |
+ VM_EXIT_SAVE_VMX_PREEMPTION_TIMER);
+
if (vmx_pt_mode_is_system())
vmexit_ctrl &= ~(VM_EXIT_PT_CONCEAL_PIP |
VM_EXIT_CLEAR_IA32_RTIT_CTL);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 3cfacf04be09..ce99704a37b7 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -510,7 +510,10 @@ static inline u8 vmx_get_rvi(void)
#endif
#define KVM_OPTIONAL_VMX_VM_EXIT_CONTROLS \
(VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL | \
+ VM_EXIT_SAVE_IA32_PAT | \
VM_EXIT_LOAD_IA32_PAT | \
+ VM_EXIT_SAVE_IA32_EFER | \
+ VM_EXIT_SAVE_VMX_PREEMPTION_TIMER | \
VM_EXIT_LOAD_IA32_EFER | \
VM_EXIT_CLEAR_BNDCFGS | \
VM_EXIT_PT_CONCEAL_PIP | \
--
2.37.1.595.g718a3a8f04-goog