From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41719) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ew51e-00032U-1J for qemu-devel@nongnu.org; Wed, 14 Mar 2018 07:56:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ew51c-0004d6-3o for qemu-devel@nongnu.org; Wed, 14 Mar 2018 07:56:58 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58644 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 1ew51b-0004cx-Uo for qemu-devel@nongnu.org; Wed, 14 Mar 2018 07:56:56 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7279AEAEA2 for ; Wed, 14 Mar 2018 11:56:55 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" Date: Wed, 14 Mar 2018 11:55:57 +0000 Message-Id: <20180314115618.28831-9-dgilbert@redhat.com> In-Reply-To: <20180314115618.28831-1-dgilbert@redhat.com> References: <20180314115618.28831-1-dgilbert@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v6 08/29] libvhost-user: Open userfaultfd List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, mst@redhat.com, maxime.coquelin@redhat.com, marcandre.lureau@redhat.com, peterx@redhat.com, quintela@redhat.com Cc: aarcange@redhat.com 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 --- contrib/libvhost-user/libvhost-user.c | 42 +++++++++++++++++++++++++++++= ++++-- contrib/libvhost-user/libvhost-user.h | 3 +++ 2 files changed, 43 insertions(+), 2 deletions(-) diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-use= r/libvhost-user.c index ed9f3148d3..9e31f47b7a 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 diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-use= r/libvhost-user.h index 00d78a8810..074b7860f6 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 { --=20 2.14.3