[PATCH 3/5] KVM: VMX: add vcpu_clear()

From: Avi Kivity
Date: Tue Jan 30 2007 - 09:55:37 EST


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@xxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>

Index: linux-2.6/drivers/kvm/vmx.c
===================================================================
--- linux-2.6.orig/drivers/kvm/vmx.c
+++ linux-2.6/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(st

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;
-
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