From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51081) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ey7mX-0006sw-N9 for qemu-devel@nongnu.org; Mon, 19 Mar 2018 23:17:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ey7mU-0008Ic-GU for qemu-devel@nongnu.org; Mon, 19 Mar 2018 23:17:49 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53458 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ey7mU-0008IW-Az for qemu-devel@nongnu.org; Mon, 19 Mar 2018 23:17:46 -0400 Date: Tue, 20 Mar 2018 05:17:45 +0200 From: "Michael S. Tsirkin" Message-ID: <1521515720-612046-30-git-send-email-mst@redhat.com> References: <1521515720-612046-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1521515720-612046-1-git-send-email-mst@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PULL v2 29/50] libvhost-user: Open userfaultfd List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , "Dr. David Alan Gilbert" , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Maxime Coquelin , Yongji Xie , Peter Xu From: "Dr. David Alan Gilbert" Open a userfaultfd (on a postcopy_advise) and send it back in the reply to the qemu for it to monitor. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Marc-Andr=C3=A9 Lureau Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- contrib/libvhost-user/libvhost-user.h | 3 +++ contrib/libvhost-user/libvhost-user.c | 42 +++++++++++++++++++++++++++++= ++++-- 2 files changed, 43 insertions(+), 2 deletions(-) diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-use= r/libvhost-user.h index 00d78a8..074b786 100644 --- a/contrib/libvhost-user/libvhost-user.h +++ b/contrib/libvhost-user/libvhost-user.h @@ -282,6 +282,9 @@ struct VuDev { * re-initialize */ vu_panic_cb panic; const VuDevIface *iface; + + /* Postcopy data */ + int postcopy_ufd; }; =20 typedef struct VuVirtqElement { diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-use= r/libvhost-user.c index ed9f314..9e31f47 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -26,9 +26,20 @@ #include #include #include +#include "qemu/compiler.h" + +#if defined(__linux__) +#include +#include +#include #include =20 -#include "qemu/compiler.h" +#ifdef __NR_userfaultfd +#include +#endif + +#endif + #include "qemu/atomic.h" =20 #include "libvhost-user.h" @@ -888,8 +899,35 @@ vu_set_config(VuDev *dev, VhostUserMsg *vmsg) static bool vu_set_postcopy_advise(VuDev *dev, VhostUserMsg *vmsg) { - /* TODO: Open ufd, pass it back in the request */ + dev->postcopy_ufd =3D -1; +#ifdef UFFDIO_API + struct uffdio_api api_struct; + + dev->postcopy_ufd =3D syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLO= CK); vmsg->size =3D 0; +#endif + + if (dev->postcopy_ufd =3D=3D -1) { + vu_panic(dev, "Userfaultfd not available: %s", strerror(errno)); + goto out; + } + +#ifdef UFFDIO_API + api_struct.api =3D UFFD_API; + api_struct.features =3D 0; + if (ioctl(dev->postcopy_ufd, UFFDIO_API, &api_struct)) { + vu_panic(dev, "Failed UFFDIO_API: %s", strerror(errno)); + close(dev->postcopy_ufd); + dev->postcopy_ufd =3D -1; + goto out; + } + /* TODO: Stash feature flags somewhere */ +#endif + +out: + /* Return a ufd to the QEMU */ + vmsg->fd_num =3D 1; + vmsg->fds[0] =3D dev->postcopy_ufd; return true; /* =3D send a reply */ } =20 --=20 MST