[11/16] KVM: nVMX: do early preparation of vmcs02 before check_vmentry_postreqs()

Commit Message

Sean Christopherson July 31, 2018, 3:32 p.m. UTC

In anticipation of using vmcs02 to do early consistency checks, move
the early preparation of vmcs02 prior to checking the postreqs.  The
downside of this approach is that we'll unnecessary load vmcs02 in
the case that check_vmentry_postreqs() fails, but that is essentially
our slow path anyways (not actually slow, but it's the path we don't
really care about optimizing).

Signed-off-by: Sean Christopherson <[e-mail]>
---
 arch/x86/kvm/vmx.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 6e7ee3637f12..d5328518b1c6 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11808,6 +11808,15 @@  static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu)
 	u32 msr_entry_idx;
 	u32 exit_qual;
 
+	if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
+		vmx->nested.vmcs01_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
+
+	vmx_switch_vmcs(vcpu, &vmx->nested.vmcs02);
+
+	prepare_vmcs02_early(vmx, vmcs12);
+
+	nested_get_vmcs12_pages(vcpu, vmcs12);
+
 	if (!is_vmentry)
 		goto enter_non_root_mode;
 
@@ -11817,22 +11826,14 @@  static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu)
 enter_non_root_mode:
 	enter_guest_mode(vcpu);
 
-	if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
-		vmx->nested.vmcs01_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
-
-	vmx_switch_vmcs(vcpu, &vmx->nested.vmcs02);
 	vmx_segment_cache_clear(vmx);
 
 	if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)
 		vcpu->arch.tsc_offset += vmcs12->tsc_offset;
 
-	prepare_vmcs02_early(vmx, vmcs12);
-
 	if (prepare_vmcs02(vcpu, vmcs12, &exit_qual))
 		goto fail;
 
-	nested_get_vmcs12_pages(vcpu, vmcs12);
-
 	exit_reason = EXIT_REASON_MSR_LOAD_FAIL;
 	msr_entry_idx = nested_vmx_load_msr(vcpu,
 					    vmcs12->vm_entry_msr_load_addr,
@@ -11852,7 +11853,6 @@  static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu)
 	if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)
 		vcpu->arch.tsc_offset -= vmcs12->tsc_offset;
 	leave_guest_mode(vcpu);
-	vmx_switch_vmcs(vcpu, &vmx->vmcs01);
 
 	/*
 	 * A consistency check VMExit during L1's VMEnter to L2 is a subset
@@ -11861,6 +11861,7 @@  static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu)
 	 * reason and exit-qualification parameters).
 	 */
 consistency_check_vmexit:
+	vmx_switch_vmcs(vcpu, &vmx->vmcs01);
 	vm_entry_controls_reset_shadow(vmx);
 	vm_exit_controls_reset_shadow(vmx);
 	vmx_segment_cache_clear(vmx);