[v3,14/20] KVM: nVMX: do early preparation of vmcs02 before check_vmentry_postreqs()
diff mbox series

Message ID 20180926162358.10741-15-sean.j.christopherson@intel.com
State New
Headers show
Series
  • KVM: nVMX: add option to perform early consistency checks via H/W
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Commit Message

Sean Christopherson Sept. 26, 2018, 4:23 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 <sean.j.christopherson@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
---
 arch/x86/kvm/vmx.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

Patch
diff mbox series

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5a2566ee4975..84708d4461a5 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -12604,27 +12604,28 @@  static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
 	u32 exit_reason = EXIT_REASON_INVALID_STATE;
 	u32 exit_qual;
 
-	if (from_vmentry && check_vmentry_postreqs(vcpu, vmcs12, &exit_qual))
-		goto vmentry_fail_vmexit;
-
-	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);
 
-	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 (from_vmentry) {
+		nested_get_vmcs12_pages(vcpu);
+
+		if (check_vmentry_postreqs(vcpu, vmcs12, &exit_qual))
+			goto vmentry_fail_vmexit;
+	}
+
+	enter_guest_mode(vcpu);
+	if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)
+		vcpu->arch.tsc_offset += vmcs12->tsc_offset;
+
 	if (prepare_vmcs02(vcpu, vmcs12, &exit_qual))
 		goto vmentry_fail_vmexit_guest_mode;
 
 	if (from_vmentry) {
-		nested_get_vmcs12_pages(vcpu);
-
 		exit_reason = EXIT_REASON_MSR_LOAD_FAIL;
 		exit_qual = nested_vmx_load_msr(vcpu,
 						vmcs12->vm_entry_msr_load_addr,
@@ -12659,12 +12660,13 @@  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);
-
-	if (!from_vmentry)
-		return 1;
 
 vmentry_fail_vmexit:
+	vmx_switch_vmcs(vcpu, &vmx->vmcs01);
+
+	if (!from_vmentry)
+		return 1;
+
 	load_vmcs12_host_state(vcpu, vmcs12);
 	vmcs12->vm_exit_reason = exit_reason | VMX_EXIT_REASONS_FAILED_VMENTRY;
 	vmcs12->exit_qualification = exit_qual;