[08/16] KVM: nVMX: move check_vmentry_postreqs() call to nested_vmx_enter_non_root_mode()

Commit Message

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

In preparation of supporting checkpoint/restore for nested state,
commit ca0bde28f2ed ("kvm: nVMX: Split VMCS checks from nested_vmx_run()")
modified check_vmentry_postreqs() to only perform the guest EFER
consistency checks when nested_run_pending is true.  But, in the
normal nested VMEntry flow, nested_run_pending is only set after
check_vmentry_postreqs(), i.e. the consistency check is being skipped.

Alternatively, nested_run_pending could be set prior to calling
check_vmentry_postreqs() in nested_vmx_run(), but placing the
consistency checks in nested_vmx_enter_non_root_mode() allows us
to split prepare_vmcs02() and interleave the preparation with
the consistency checks without having to change the call sites
of nested_vmx_enter_non_root_mode().  In other words, the rest
of the consistency check code in nested_vmx_run() will be joining
the postreqs checks in future patches.

Fixes: ca0bde28f2ed ("kvm: nVMX: Split VMCS checks from nested_vmx_run()")
Signed-off-by: Sean Christopherson <[e-mail]>
Cc: Jim Mattson <[e-mail]>
---
 arch/x86/kvm/vmx.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index f3b8cc803025..c01ae6e7c323 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11769,10 +11769,22 @@  static int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
+	bool is_vmentry = vmx->nested.nested_run_pending;
 	u32 msr_entry_idx;
 	u32 exit_qual;
 	int r;
 
+	if (!is_vmentry)
+		goto enter_non_root_mode;
+
+	r = check_vmentry_postreqs(vcpu, vmcs12, &exit_qual);
+	if (r) {
+		nested_vmx_entry_failure(vcpu, vmcs12,
+					 EXIT_REASON_INVALID_STATE, exit_qual);
+		return 1;
+	}
+
+enter_non_root_mode:
 	enter_guest_mode(vcpu);
 
 	if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
@@ -11823,7 +11835,6 @@  static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 	struct vmcs12 *vmcs12;
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	u32 interrupt_shadow = vmx_get_interrupt_shadow(vcpu);
-	u32 exit_qual;
 	int ret;
 
 	if (!nested_vmx_check_permission(vcpu))
@@ -11875,13 +11886,6 @@  static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 	 */
 	skip_emulated_instruction(vcpu);
 
-	ret = check_vmentry_postreqs(vcpu, vmcs12, &exit_qual);
-	if (ret) {
-		nested_vmx_entry_failure(vcpu, vmcs12,
-					 EXIT_REASON_INVALID_STATE, exit_qual);
-		return 1;
-	}
-
 	/*
 	 * We're finally done with prerequisite checking, and can start with
 	 * the nested entry.