Use "libvhost-user: " commit title tag/prefix?
On Thu, Aug 24, 2017 at 12:27 PM, Dr. David Alan Gilbert (git)
<[email protected]> wrote:
> From: "Dr. David Alan Gilbert" <[email protected]>
>
> When new regions are sent to the client using SET_MEM_TABLE, register
> them with the userfaultfd.
>
> Signed-off-by: Dr. David Alan Gilbert <[email protected]>
> ---
> contrib/libvhost-user/libvhost-user.c | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/contrib/libvhost-user/libvhost-user.c
> b/contrib/libvhost-user/libvhost-user.c
> index e8accf11db..e6ab059a03 100644
> --- a/contrib/libvhost-user/libvhost-user.c
> +++ b/contrib/libvhost-user/libvhost-user.c
> @@ -449,6 +449,38 @@ vu_set_mem_table_exec(VuDev *dev, VhostUserMsg *vmsg)
> dev_region->mmap_addr);
> }
>
> + if (dev->postcopy_listening) {
> + /* We should already have an open ufd need to mark each memory
> + * range as ufd.
> + * Note: Do we need any madvises? Well it's not been accessed
> + * yet, still probably need no THP to be safe, discard to be
> safe?
> + */
> + struct uffdio_register reg_struct;
> + reg_struct.range.start = (uintptr_t)dev_region->mmap_addr;
> + reg_struct.range.len = dev_region->size +
> dev_region->mmap_offset;
> + reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
> +
> + if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER, ®_struct)) {
> + vu_panic(dev, "%s: Failed to userfault region %d "
> + "@%p + %zx: (ufd=%d)%s\n",
> + __func__, i,
> + dev_region->mmap_addr,
> + dev_region->size + dev_region->mmap_offset,
> + dev->postcopy_ufd, strerror(errno));
> + continue;
panic is supposed to be unrecoverable errors, so I would suggest to return here
> + }
> + if (!(reg_struct.ioctls & ((__u64)1 << _UFFDIO_COPY))) {
> + vu_panic(dev, "%s Region (%d) doesn't support COPY",
> + __func__, i);
> + continue;
> + }
> + DPRINT("%s: region %d: Registered userfault for %llx + %llx\n",
> + __func__, i, reg_struct.range.start,
> reg_struct.range.len);
> + /* TODO: Stash 'zero' support flags somewhere */
> + /* TODO: Get address back to QEMU */
> +
> + }
> +
> close(vmsg->fds[i]);
> }
This patch would be nicer if it compiles on !Linux / without userfault.
--
Marc-André Lureau
