From: Avi Kivity <avi@qumranet.com>
Date: Mon, 12 Feb 2007 08:54:46 +0000 (-0800)
Subject: [PATCH] KVM: VMX: add vcpu_clear()
X-Git-Tag: v2.6.21-rc1~274^2~50
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8d0be2b3bf4a55606967d7d84e56c52521e94333;p=linux-2.6

[PATCH] KVM: VMX: add vcpu_clear()

Like the inline code it replaces, this function decaches the vmcs from the cpu
it last executed on.  in addition:

 - vcpu_clear() works if the last cpu is also the cpu we're running on
 - it is faster on larger smps by virtue of using smp_call_function_single()

Includes fix from Ingo Molnar.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 407862825c..28da0cae64 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -125,6 +125,15 @@ static void __vcpu_clear(void *arg)
 		per_cpu(current_vmcs, cpu) = NULL;
 }
 
+static void vcpu_clear(struct kvm_vcpu *vcpu)
+{
+	if (vcpu->cpu != raw_smp_processor_id() && vcpu->cpu != -1)
+		smp_call_function_single(vcpu->cpu, __vcpu_clear, vcpu, 0, 1);
+	else
+		__vcpu_clear(vcpu);
+	vcpu->launched = 0;
+}
+
 static unsigned long vmcs_readl(unsigned long field)
 {
 	unsigned long value;
@@ -202,10 +211,8 @@ static struct kvm_vcpu *vmx_vcpu_load(struct kvm_vcpu *vcpu)
 
 	cpu = get_cpu();
 
-	if (vcpu->cpu != cpu) {
-		smp_call_function(__vcpu_clear, vcpu, 0, 1);
-		vcpu->launched = 0;
-	}
+	if (vcpu->cpu != cpu)
+		vcpu_clear(vcpu);
 
 	if (per_cpu(current_vmcs, cpu) != vcpu->vmcs) {
 		u8 error;