From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41388) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dZhVJ-0004v7-Po for qemu-devel@nongnu.org; Mon, 24 Jul 2017 13:50:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dZhVE-0005to-UD for qemu-devel@nongnu.org; Mon, 24 Jul 2017 13:50:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56314) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dZhVE-0005tV-CV for qemu-devel@nongnu.org; Mon, 24 Jul 2017 13:50:44 -0400 Date: Mon, 24 Jul 2017 18:50:31 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170724175031.GG2127@work-vm> References: <20170628190047.26159-1-dgilbert@redhat.com> <20170628190047.26159-15-dgilbert@redhat.com> <726dd083-341b-aa13-37d2-b66479f6039a@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <726dd083-341b-aa13-37d2-b66479f6039a@redhat.com> 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: Maxime Coquelin Cc: 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 * Maxime Coquelin (maxime.coquelin@redhat.com) wrote: > > > 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? Fixed. Thanks for spotting that; adding a GCC_FMT_ATTR(2, 3) before vu_panic doesn't show any more from me, but there are a couple of existing cases that look wrong; I think they just need a * before them, but am not 100% sure. Dave > > + 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]); > > } > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK