From bccf2150fe62dda5fb09efa2f64d2a234694eb48 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 21 Feb 2007 18:04:26 +0200 Subject: KVM: Per-vcpu inodes Allocate a distinct inode for every vcpu in a VM. This has the following benefits: - the filp cachelines are no longer bounced when f_count is incremented on every ioctl() - the API and internal code are distinctly clearer; for example, on the KVM_GET_REGS ioctl, there is no need to copy the vcpu number from userspace and then copy the registers back; the vcpu identity is derived from the fd used to make the call Right now the performance benefits are completely theoretical since (a) we don't support more than one vcpu per VM and (b) virtualization hardware inefficiencies completely everwhelm any cacheline bouncing effects. But both of these will change, and we need to prepare the API today. Signed-off-by: Avi Kivity --- drivers/kvm/vmx.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/kvm/vmx.c') diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index ff956a6302e..c07178e6112 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -204,7 +204,7 @@ static void vmcs_write64(unsigned long field, u64 value) * Switches to specified vcpu, until a matching vcpu_put(), but assumes * vcpu mutex is already taken. */ -static struct kvm_vcpu *vmx_vcpu_load(struct kvm_vcpu *vcpu) +static void vmx_vcpu_load(struct kvm_vcpu *vcpu) { u64 phys_addr = __pa(vcpu->vmcs); int cpu; @@ -242,7 +242,6 @@ static struct kvm_vcpu *vmx_vcpu_load(struct kvm_vcpu *vcpu) rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp); vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */ } - return vcpu; } static void vmx_vcpu_put(struct kvm_vcpu *vcpu) -- cgit v1.2.3