Re: [PATCH v4 1/2] KVM: nVMX: enhance allocate/free_vpid to handle shadow vpid

From: Wanpeng Li
Date: Wed Sep 16 2015 - 05:14:43 EST


On 9/16/15 5:11 PM, Jan Kiszka wrote:
On 2015-09-16 09:19, Wanpeng Li wrote:
Enhance allocate/free_vid to handle shadow vpid.

Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 9ff6a3f..c5222b8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4155,29 +4155,28 @@ static int alloc_identity_pagetable(struct kvm *kvm)
return r;
}
-static void allocate_vpid(struct vcpu_vmx *vmx)
+static int allocate_vpid(void)
{
int vpid;
- vmx->vpid = 0;
if (!enable_vpid)
- return;
+ return 0;
spin_lock(&vmx_vpid_lock);
vpid = find_first_zero_bit(vmx_vpid_bitmap, VMX_NR_VPIDS);
- if (vpid < VMX_NR_VPIDS) {
- vmx->vpid = vpid;
+ if (vpid < VMX_NR_VPIDS)
__set_bit(vpid, vmx_vpid_bitmap);
- }
+ else
+ vpid = 0;
spin_unlock(&vmx_vpid_lock);
+ return vpid;
}
-static void free_vpid(struct vcpu_vmx *vmx)
+static void free_vpid(int vpid)
{
if (!enable_vpid)
|| vpid == 0

Otherwise you clear bit zero and cause the next allocate_vpid return 0 -
from the bitmap.

Will do, thanks. :-)

Regards,
Wanpeng Li
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