On 2015-09-16 05:51, Wanpeng Li wrote:
> Enhance allocate/free_vid to handle shadow vpid.
>
> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
> ---
> arch/x86/kvm/vmx.c | 24 +++++++++++-------------
> 1 file changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 9ff6a3f..4956081 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -4155,29 +4155,27 @@ 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;
> + int vpid = 0;
Initialization is not pointless with the current code.
>
> - 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);
> - }
> spin_unlock(&vmx_vpid_lock);
> + return vpid;
You should return 0 also if vpid == VMX_NR_VPIDS.
> }
>
> -static void free_vpid(struct vcpu_vmx *vmx)
> +static void free_vpid(int vpid)
> {
> if (!enable_vpid)
You could already test for vpid == 0 here...
> return;
> spin_lock(&vmx_vpid_lock);
> - if (vmx->vpid != 0)
> - __clear_bit(vmx->vpid, vmx_vpid_bitmap);
> + if (vpid != 0)
...then you could skip this.
> + __clear_bit(vpid, vmx_vpid_bitmap);
> spin_unlock(&vmx_vpid_lock);
> }
>
> @@ -8482,7 +8480,7 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
>
> if (enable_pml)
> vmx_disable_pml(vmx);
> - free_vpid(vmx);
> + free_vpid(vmx->vpid);
> leave_guest_mode(vcpu);
> vmx_load_vmcs01(vcpu);
> free_nested(vmx);
> @@ -8501,7 +8499,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
> if (!vmx)
> return ERR_PTR(-ENOMEM);
>
> - allocate_vpid(vmx);
> + vmx->vpid = allocate_vpid();
>
> err = kvm_vcpu_init(&vmx->vcpu, kvm, id);
> if (err)
> @@ -8577,7 +8575,7 @@ free_msrs:
> uninit_vcpu:
> kvm_vcpu_uninit(&vmx->vcpu);
> free_vcpu:
> - free_vpid(vmx);
> + free_vpid(vmx->vpid);
> kmem_cache_free(kvm_vcpu_cache, vmx);
> return ERR_PTR(err);
> }
>
Yes, this is what I had in mind.
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux
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