Re: [PATCH net-next 8/8] vhost: event suppression for packed ring

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





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




[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux