From: Sean Christopherson <sean.j.christopherson@intel.com>
Date: Wed, 26 Sep 2018 09:23:46 -0700
Subject: KVM: nVMX: move check_vmentry_postreqs() call to
 nested_vmx_enter_non_root_mode()
Git-commit: 7671ce21b13b9596163a29f4712cb2451a9b97dc
Patch-mainline: v4.20-rc1
References: bsc#1106240

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 <sean.j.christopherson@intel.com>
Cc: Jim Mattson <jmattson@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/kvm/vmx.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11356,7 +11356,8 @@ static int enter_vmx_non_root_mode(struc
 
 	vmx_switch_vmcs(vcpu, &vmx->nested.vmcs02);
 
-	if (prepare_vmcs02(vcpu, vmcs12, &exit_qual)) {
+	if (prepare_vmcs02(vcpu, vmcs12, &exit_qual) ||
+	    (!!exit_qual && check_vmentry_postreqs(vcpu, vmcs12, &exit_qual))) {
 		leave_guest_mode(vcpu);
 		vmx_switch_vmcs(vcpu, &vmx->vmcs01);
 		nested_vmx_entry_failure(vcpu, vmcs12,
@@ -11395,7 +11396,6 @@ static int nested_vmx_run(struct kvm_vcp
 	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))
@@ -11447,13 +11447,6 @@ static int nested_vmx_run(struct kvm_vcp
 	 */
 	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;
-	}
-
 	/* Hide L1D cache contents from the nested guest.  */
 	vmx->vcpu.arch.l1tf_flush_l1d = true;