Messages in this thread | | | Subject | Re: [PATCH net-next 8/8] vhost: event suppression for packed ring | From | Jason Wang <> | Date | Wed, 4 Jul 2018 13:23:18 +0800 |
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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@redhat.com> >> --- >> 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
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