linux-kernel - [PATCH v2 2/5] KVM: VMX: Reorder some skip_emulated

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Date:   Tue, 29 Nov 2016 12:40:38 -0800
From:   Kyle Huey <me@...ehuey.com>
To:     Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        Joerg Roedel <joro@...tes.org>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 2/5] KVM: VMX: Reorder some skip_emulated_instruction calls

The functions being moved ahead of skip_emulated_instruction here don't
need updated IPs, and skipping the emulated instruction at the end will
make it easier to return its value.

Signed-off-by: Kyle Huey <khuey@...ehuey.com>
---
 arch/x86/kvm/vmx.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e4af9699..f2f9cf5 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5703,18 +5703,18 @@ static int handle_cr(struct kvm_vcpu *vcpu)
 				vcpu->run->exit_reason = KVM_EXIT_SET_TPR;
 				return 0;
 			}
 		}
 		break;
 	case 2: /* clts */
 		handle_clts(vcpu);
 		trace_kvm_cr_write(0, kvm_read_cr0(vcpu));
-		skip_emulated_instruction(vcpu);
 		vmx_fpu_activate(vcpu);
+		skip_emulated_instruction(vcpu);
 		return 1;
 	case 1: /*mov from cr*/
 		switch (cr) {
 		case 3:
 			val = kvm_read_cr3(vcpu);
 			kvm_register_write(vcpu, reg, val);
 			trace_kvm_cr_read(cr, val);
 			skip_emulated_instruction(vcpu);
@@ -6128,18 +6128,18 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
 
 static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
 {
 	int ret;
 	gpa_t gpa;
 
 	gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
 	if (!kvm_io_bus_write(vcpu, KVM_FAST_MMIO_BUS, gpa, 0, NULL)) {
-		skip_emulated_instruction(vcpu);
 		trace_kvm_fast_mmio(gpa);
+		skip_emulated_instruction(vcpu);
 		return 1;
 	}
 
 	ret = handle_mmio_page_fault(vcpu, gpa, true);
 	if (likely(ret == RET_MMIO_PF_EMULATE))
 		return x86_emulate_instruction(vcpu, gpa, 0, NULL, 0) ==
 					      EMULATE_DONE;
 
@@ -6502,18 +6502,18 @@ static __exit void hardware_unsetup(void)
  * Indicate a busy-waiting vcpu in spinlock. We do not enable the PAUSE
  * exiting, so only get here on cpu with PAUSE-Loop-Exiting.
  */
 static int handle_pause(struct kvm_vcpu *vcpu)
 {
 	if (ple_gap)
 		grow_ple_window(vcpu);
 
-	skip_emulated_instruction(vcpu);
 	kvm_vcpu_on_spin(vcpu);
+	skip_emulated_instruction(vcpu);
 
 	return 1;
 }
 
 static int handle_nop(struct kvm_vcpu *vcpu)
 {
 	skip_emulated_instruction(vcpu);
 	return 1;
@@ -6957,18 +6957,18 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
 	vmx->nested.vmcs02_num = 0;
 
 	hrtimer_init(&vmx->nested.preemption_timer, CLOCK_MONOTONIC,
 		     HRTIMER_MODE_REL_PINNED);
 	vmx->nested.preemption_timer.function = vmx_preemption_timer_fn;
 
 	vmx->nested.vmxon = true;
 
-	skip_emulated_instruction(vcpu);
 	nested_vmx_succeed(vcpu);
+	skip_emulated_instruction(vcpu);
 	return 1;
 
 out_shadow_vmcs:
 	kfree(vmx->nested.cached_vmcs12);
 
 out_cached_vmcs12:
 	free_page((unsigned long)vmx->nested.msr_bitmap);
 
@@ -7078,18 +7078,18 @@ static void free_nested(struct vcpu_vmx *vmx)
 }
 
 /* Emulate the VMXOFF instruction */
 static int handle_vmoff(struct kvm_vcpu *vcpu)
 {
 	if (!nested_vmx_check_permission(vcpu))
 		return 1;
 	free_nested(to_vmx(vcpu));
-	skip_emulated_instruction(vcpu);
 	nested_vmx_succeed(vcpu);
+	skip_emulated_instruction(vcpu);
 	return 1;
 }
 
 /* Emulate the VMCLEAR instruction */
 static int handle_vmclear(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	gpa_t vmptr;
@@ -7119,18 +7119,18 @@ static int handle_vmclear(struct kvm_vcpu *vcpu)
 	}
 	vmcs12 = kmap(page);
 	vmcs12->launch_state = 0;
 	kunmap(page);
 	nested_release_page(page);
 
 	nested_free_vmcs02(vmx, vmptr);
 
-	skip_emulated_instruction(vcpu);
 	nested_vmx_succeed(vcpu);
+	skip_emulated_instruction(vcpu);
 	return 1;
 }
 
 static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch);
 
 /* Emulate the VMLAUNCH instruction */
 static int handle_vmlaunch(struct kvm_vcpu *vcpu)
 {
-- 
2.10.2