Re: [PATCH v5 1/2] KVM: nVMX: enhance allocate/free_vpid to handle shadow vpid

[Paolo Bonzini <pbonzini@redhat.com>]

On 16/09/2015 11:30, Wanpeng Li wrote:
> Enhance allocate/free_vid to handle shadow vpid.

Adjusting the commit message:

    KVM: nVMX: adjust interface to allocate/free_vpid
    
    Adjust allocate/free_vid so that they can be reused for the nested vpid.

and committing to kvm/queue.

Paolo

> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
> ---
>  arch/x86/kvm/vmx.c | 25 ++++++++++++-------------
>  1 file changed, 12 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 9ff6a3f..f8d704d 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)
> +	if (!enable_vpid || vpid == 0)
>  		return;
>  	spin_lock(&vmx_vpid_lock);
> -	if (vmx->vpid != 0)
> -		__clear_bit(vmx->vpid, vmx_vpid_bitmap);
> +	__clear_bit(vpid, vmx_vpid_bitmap);
>  	spin_unlock(&vmx_vpid_lock);
>  }
>  
> @@ -8482,7 +8481,7 @@ 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 +8500,7 @@ 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 +8576,7 @@ 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);
>  }
>