On 2018年07月04日 12:13, Wei Xu wrote:
On Tue, Jul 03, 2018 at 01:38:04PM +0800, Jason Wang wrote:
This patch introduces support for event suppression. This is done by
have a two areas: device area and driver area. One side could then try
to disable or enable (delayed) notification from other side by using a
boolean hint or event index interface in the areas.
For more information, please refer Virtio spec.
Signed-off-by: Jason Wang<jasowang@xxxxxxxxxx>
---
drivers/vhost/vhost.c | 191 ++++++++++++++++++++++++++++++++++++++++++++++----
drivers/vhost/vhost.h | 10 ++-
2 files changed, 185 insertions(+), 16 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 0f3f07c..cccbc82 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1115,10 +1115,15 @@ static int vq_access_ok_packed(struct vhost_virtqueue *vq, unsigned int num,
struct vring_used __user *used)
{
struct vring_desc_packed *packed = (struct vring_desc_packed *)desc;
+ struct vring_packed_desc_event *driver_event =
+ (struct vring_packed_desc_event *)avail;
+ struct vring_packed_desc_event *device_event =
+ (struct vring_packed_desc_event *)used;
- /* TODO: check device area and driver area */
return access_ok(VERIFY_READ, packed, num * sizeof(*packed)) &&
- access_ok(VERIFY_WRITE, packed, num * sizeof(*packed));
+ access_ok(VERIFY_WRITE, packed, num * sizeof(*packed)) &&
R/W parameter doesn't make sense to most architectures and the comment in x86
says WRITE is a superset of READ, is it possible to converge them here?
/**
* access_ok: - Checks if a user space pointer is valid
* @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
* %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
* to write to a block, it is always safe to read from it.
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
* Context: User context only. This function may sleep if pagefaults are
* enabled.
*
* Checks if a pointer to a block of memory in user space is valid.
*
* Returns true (nonzero) if the memory block may be valid, false (zero)
* if it is definitely invalid.
*
* Note that, depending on architecture, this function probably just
* checks that the pointer is in the user space range - after calling
* this function, memory access functions may still return -EFAULT.
*/
#define access_ok(type, addr, size)
......
Thanks,
Wei
Well, this is a question that beyond the scope of this patch.
My understanding is we should keep it unless type was meaningless on all
archs.
Thanks
