From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55986) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dZfBh-0001vn-8B for qemu-devel@nongnu.org; Mon, 24 Jul 2017 11:22:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dZfBe-0005Jf-2R for qemu-devel@nongnu.org; Mon, 24 Jul 2017 11:22:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35754) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dZfBd-0005JH-PV for qemu-devel@nongnu.org; Mon, 24 Jul 2017 11:22:22 -0400 References: <20170628190047.26159-1-dgilbert@redhat.com> <20170628190047.26159-15-dgilbert@redhat.com> From: Maxime Coquelin Message-ID: <726dd083-341b-aa13-37d2-b66479f6039a@redhat.com> Date: Mon, 24 Jul 2017 17:22:08 +0200 MIME-Version: 1.0 In-Reply-To: <20170628190047.26159-15-dgilbert@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC 14/29] vhost+postcopy: Register new regions with the ufd List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" , qemu-devel@nongnu.org, a.perevalov@samsung.com, marcandre.lureau@redhat.com, mst@redhat.com, quintela@redhat.com, peterx@redhat.com, lvivier@redhat.com, aarcange@redhat.com On 06/28/2017 09:00 PM, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" > > When new regions are sent to the client using SET_MEM_TABLE, register > them with the userfaultfd. > > Signed-off-by: Dr. David Alan Gilbert > --- > contrib/libvhost-user/libvhost-user.c | 33 +++++++++++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) > > diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c > index 6de339fb7a..be7470e3a9 100644 > --- a/contrib/libvhost-user/libvhost-user.c > +++ b/contrib/libvhost-user/libvhost-user.c > @@ -450,6 +450,39 @@ 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; > + /* Note: We might need to go back to using mmap_addr and > + * len + mmap_offset for * huge pages, but then we do hope not to > + * see accesses in that area below the offset > + */ > + reg_struct.range.start = (uintptr_t)(dev_region->mmap_addr + > + dev_region->mmap_offset); > + reg_struct.range.len = dev_region->size; > + reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING; > + > + if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER, ®_struct)) { > + vu_panic(dev, "%s: Failed to userfault region %d: (ufd=%d)%s\n", > + __func__, i, strerror(errno), dev->postcopy_ufd); Aren't the two last args swapped? > + continue; > + } > + 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]); > } > >