@@ -11897,6 +11897,17 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne
return 0;
}
+static u64 nested_vmx_calc_efer(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
+{
+ if (vmx->nested.nested_run_pending &&
+ (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER))
+ return vmcs12->guest_ia32_efer;
+ else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
+ return vmx->vcpu.arch.efer | (EFER_LMA | EFER_LME);
+ else
+ return vmx->vcpu.arch.efer & ~(EFER_LMA | EFER_LME);
+}
+
static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -12036,6 +12047,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 exec_control, vmcs12_exec_ctrl;
+ u64 guest_efer;
if (vmx->nested.dirty_vmcs12) {
prepare_vmcs02_full(vcpu, vmcs12);
@@ -12185,19 +12197,32 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
vcpu->arch.cr0_guest_owned_bits &= ~vmcs12->cr0_guest_host_mask;
vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);
+ /*
+ * vmcs12's VM_{ENTRY,EXIT}_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE
+ * are emulated by vmx_set_efer(), below, but speculate on the
+ * related bits (if supported by the CPU) in the hope that we can
+ * avoid VMWrites during vmx_set_efer().
+ */
+ guest_efer = nested_vmx_calc_efer(vmx, vmcs12);
+
/* L2->L1 exit controls are emulated - the hardware exit is to L0 so
* we should use its exit controls. Note that VM_EXIT_LOAD_IA32_EFER
* bits are further modified by vmx_set_efer() below.
*/
- vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl);
+ exec_control = vmcs_config.vmexit_ctrl;
+ if (cpu_has_load_ia32_efer && guest_efer != host_efer)
+ exec_control |= VM_EXIT_LOAD_IA32_EFER;
+ vm_exit_controls_init(vmx, exec_control);
- /* vmcs12's VM_ENTRY_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE are
- * emulated by vmx_set_efer(), below.
- */
- vm_entry_controls_init(vmx,
- (vmcs12->vm_entry_controls & ~VM_ENTRY_LOAD_IA32_EFER &
- ~VM_ENTRY_IA32E_MODE) |
- (vmcs_config.vmentry_ctrl & ~VM_ENTRY_IA32E_MODE));
+ exec_control = (vmcs12->vm_entry_controls | vmcs_config.vmentry_ctrl) &
+ ~VM_ENTRY_IA32E_MODE & ~VM_ENTRY_LOAD_IA32_EFER;
+ if (cpu_has_load_ia32_efer) {
+ if (guest_efer & EFER_LMA)
+ exec_control |= VM_ENTRY_IA32E_MODE;
+ if (guest_efer != host_efer)
+ exec_control |= VM_ENTRY_LOAD_IA32_EFER;
+ }
+ vm_entry_controls_init(vmx, exec_control);
if (vmx->nested.nested_run_pending &&
(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PAT)) {
@@ -12263,14 +12288,8 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
vmx_set_cr4(vcpu, vmcs12->guest_cr4);
vmcs_writel(CR4_READ_SHADOW, nested_read_cr4(vmcs12));
- if (vmx->nested.nested_run_pending &&
- (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER))
- vcpu->arch.efer = vmcs12->guest_ia32_efer;
- else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
- vcpu->arch.efer |= (EFER_LMA | EFER_LME);
- else
- vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);
- /* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
+ vcpu->arch.efer = guest_efer;
+ /* Note: may modify VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
vmx_set_efer(vcpu, vcpu->arch.efer);
/*
VM_ENTRY_IA32E_MODE and VM_{ENTRY,EXIT}_LOAD_IA32_EFER will be explicitly set/cleared as needed by vmx_set_efer(), but attempt to get the bits set correctly when intializing the control fields. Setting the value correctly can avoid multiple VMWrites. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Jim Mattson <jmattson@google.com> --- arch/x86/kvm/vmx.c | 51 +++++++++++++++++++++++++++++++--------------- 1 file changed, 35 insertions(+), 16 deletions(-)