diff mbox series

[RFC,02/19] drivers/vhost: Convert to use vm_account

Message ID 97a17a6ab7e59be4287a2a94d43bb787300476b4.1674538665.git-series.apopple@nvidia.com (mailing list archive)
State RFC
Headers show
Series [RFC,01/19] mm: Introduce vm_account | expand

Commit Message

Alistair Popple Jan. 24, 2023, 5:42 a.m. UTC
Convert vhost to use the new vm_account structure and associated
account_pinned_vm() functions.

Signed-off-by: Alistair Popple <apopple@nvidia.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/vhost/vdpa.c  |  9 +++++----
 drivers/vhost/vhost.c |  2 ++
 drivers/vhost/vhost.h |  1 +
 3 files changed, 8 insertions(+), 4 deletions(-)

Comments

Michael S. Tsirkin Jan. 24, 2023, 5:55 a.m. UTC | #1
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?

> -- 
> git-series 0.9.1
Jason Gunthorpe Jan. 24, 2023, 2:34 p.m. UTC | #2
On Tue, Jan 24, 2023 at 04:42:31PM +1100, Alistair Popple wrote:

> @@ -799,9 +803,6 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
>  		return r;
>  	}
>  
> -	if (!vdpa->use_va)
> -		atomic64_add(PFN_DOWN(size), &dev->mm->pinned_vm);

Mention in the commit message this fixes a "bug" where vhost didn't
respect the limits

Jason
Alistair Popple Jan. 30, 2023, 10:43 a.m. UTC | #3
"Michael S. Tsirkin" <mst@redhat.com> 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
diff mbox series

Patch

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
@@ -716,7 +716,7 @@  static void vhost_vdpa_pa_unmap(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
 				set_page_dirty_lock(page);
 			unpin_user_page(page);
 		}
-		atomic64_sub(PFN_DOWN(map->size), &dev->mm->pinned_vm);
+		vm_unaccount_pinned(&dev->vm_account, PFN_DOWN(map->size));
 		vhost_vdpa_general_unmap(v, map, asid);
 		vhost_iotlb_map_free(iotlb, map);
 	}
@@ -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)
@@ -799,9 +803,6 @@  static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
 		return r;
 	}
 
-	if (!vdpa->use_va)
-		atomic64_add(PFN_DOWN(size), &dev->mm->pinned_vm);
-
 	return 0;
 }
 
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index cbe72bf..5645c26 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -556,6 +556,7 @@  static void vhost_attach_mm(struct vhost_dev *dev)
 		dev->mm = current->mm;
 		mmgrab(dev->mm);
 	}
+	vm_account_init_current(&dev->vm_account);
 }
 
 static void vhost_detach_mm(struct vhost_dev *dev)
@@ -569,6 +570,7 @@  static void vhost_detach_mm(struct vhost_dev *dev)
 		mmdrop(dev->mm);
 
 	dev->mm = NULL;
+	vm_account_release(&dev->vm_account);
 }
 
 /* Caller should have device mutex */
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index d910910..3a9aed8 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -144,6 +144,7 @@  struct vhost_msg_node {
 struct vhost_dev {
 	struct mm_struct *mm;
 	struct mutex mutex;
+	struct vm_account vm_account;
 	struct vhost_virtqueue **vqs;
 	int nvqs;
 	struct eventfd_ctx *log_ctx;