diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-05-07 12:18:02 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-06-18 11:47:45 +0200 |
| commit | 469debdb8be5814c71c146ce8e21ae7363ae644d (patch) | |
| tree | 698d1aa91975b05748862bc8f12342575d04af1b | |
| parent | de0286b7884a6a3309e299dda876810faa281547 (diff) | |
KVM: nVMX: Preset *DT exiting in vmcs02 when emulating UMIP
KVM dynamically toggles SECONDARY_EXEC_DESC to intercept (a subset of)
instructions that are subject to User-Mode Instruction Prevention, i.e.
VMCS.SECONDARY_EXEC_DESC == CR4.UMIP when emulating UMIP. Preset the
VMCS control when preparing vmcs02 to avoid unnecessarily VMWRITEs,
e.g. KVM will clear VMCS.SECONDARY_EXEC_DESC in prepare_vmcs02_early()
and then set it in vmx_set_cr4().
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 54b7726c5bf5..23c310adea7d 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2085,6 +2085,14 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) /* VMCS shadowing for L2 is emulated for now */ exec_control &= ~SECONDARY_EXEC_SHADOW_VMCS; + /* + * Preset *DT exiting when emulating UMIP, so that vmx_set_cr4() + * will not have to rewrite the controls just for this bit. + */ + if (!boot_cpu_has(X86_FEATURE_UMIP) && vmx_umip_emulated() && + (vmcs12->guest_cr4 & X86_CR4_UMIP)) + exec_control |= SECONDARY_EXEC_DESC; + if (exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) vmcs_write16(GUEST_INTR_STATUS, vmcs12->guest_intr_status); |