Subject: Re: [RFC PATCH 02/19] drivers/vhost: Convert to use vm_account

From: Alistair Popple <[email-masked]>
Date: Mon, 30 Jan 2023 21:43:52 +1100

"Michael S. Tsirkin" <[email-masked]> writes:

> On Tue, Jan 24, 2023 at 04:42:31PM +1100, Alistair Popple wrote:
>> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
>> index ec32f78..a31dd53 100644
>> --- a/drivers/vhost/vdpa.c
>> +++ b/drivers/vhost/vdpa.c
>
> ...
>
>> @@ -780,6 +780,10 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
>>  	u32 asid = iotlb_to_asid(iotlb);
>>  	int r = 0;
>>  
>> +	if (!vdpa->use_va)
>> +		if (vm_account_pinned(&dev->vm_account, PFN_DOWN(size)))
>> +			return -ENOMEM;
>> +
>>  	r = vhost_iotlb_add_range_ctx(iotlb, iova, iova + size - 1,
>>  				      pa, perm, opaque);
>>  	if (r)
>
> I suspect some error handling will have to be reworked then, no?

Thanks. I had meant to go back and double check some of these driver
conversions. Will add something like below:

@@ -787,7 +787,7 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
 	r = vhost_iotlb_add_range_ctx(iotlb, iova, iova + size - 1,
 				      pa, perm, opaque);
 	if (r)
-		return r;
+		goto out_unaccount;
 
 	if (ops->dma_map) {
 		r = ops->dma_map(vdpa, asid, iova, size, pa, perm, opaque);
@@ -798,12 +798,14 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
 		r = iommu_map(v->domain, iova, pa, size,
 			      perm_to_iommu_flags(perm));
 	}
-	if (r) {
+	if (r)
 		vhost_iotlb_del_range(iotlb, iova, iova + size - 1);
-		return r;
-	}
 
-	return 0;
+out_unaccount:
+	if (!vdpa->use_va)
+		vm_unaccount_pinned(&dev->vm_account, PFN_DOWN(size));
+
+	return r;
 }
 
 static void vhost_vdpa_unmap(struct vhost_vdpa *v,

>> -- 
>> git-series 0.9.1