From nobody Mon Feb 9 00:01:32 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1503603988181773.0908711645687; Thu, 24 Aug 2017 12:46:28 -0700 (PDT) Received: from localhost ([::1]:50202 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dky5C-0002Qz-Sw for importer@patchew.org; Thu, 24 Aug 2017 15:46:26 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52965) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dkxpG-0003ix-Od for qemu-devel@nongnu.org; Thu, 24 Aug 2017 15:29:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dkxpF-0005f5-QE for qemu-devel@nongnu.org; Thu, 24 Aug 2017 15:29:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35702) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dkxpF-0005es-Ju for qemu-devel@nongnu.org; Thu, 24 Aug 2017 15:29:57 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 98986267F8; Thu, 24 Aug 2017 19:29:56 +0000 (UTC) Received: from dgilbert-t530.redhat.com (ovpn-117-165.ams2.redhat.com [10.36.117.165]) by smtp.corp.redhat.com (Postfix) with ESMTP id DB41A7F38A; Thu, 24 Aug 2017 19:29:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 98986267F8 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=dgilbert@redhat.com From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, maxime.coquelin@redhat.com, a.perevalov@samsung.com, mst@redhat.com, marcandre.lureau@redhat.com Date: Thu, 24 Aug 2017 20:27:27 +0100 Message-Id: <20170824192730.8440-30-dgilbert@redhat.com> In-Reply-To: <20170824192730.8440-1-dgilbert@redhat.com> References: <20170824192730.8440-1-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Thu, 24 Aug 2017 19:29:56 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [RFC v2 29/32] vhost-user: Claim support for postcopy X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, aarcange@redhat.com, felipe@nutanix.com, peterx@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: "Dr. David Alan Gilbert" Tell QEMU we understand the protocol features needed for postcopy. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Marc-Andr=C3=A9 Lureau --- 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 23bff47649..290748733b 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -144,6 +144,35 @@ vmsg_close_fds(VhostUserMsg *vmsg) } } =20 +/* A test to see if we have userfault available */ +static bool +have_userfault(void) +{ +#if defined(__linux__) && defined(__NR_userfaultfd) &&\ + defined(UFFD_FEATURE_MISSING_SHMEM) &&\ + defined(UFFD_FEATURE_MISSING_HUGETLBFS) + /* Now test the kernel we're running on really has the features */ + int ufd =3D syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK); + struct uffdio_api api_struct; + if (ufd < 0) { + return false; + } + + api_struct.api =3D UFFD_API; + api_struct.features =3D UFFD_FEATURE_MISSING_SHMEM | + UFFD_FEATURE_MISSING_HUGETLBFS; + if (ioctl(ufd, UFFDIO_API, &api_struct)) { + close(ufd); + return false; + } + close(ufd); + return true; + +#else + return false; +#endif +} + static bool vu_message_read(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) { @@ -796,6 +825,10 @@ vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg= *vmsg) { uint64_t features =3D 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD; =20 + if (have_userfault()) { + features |=3D 1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT; + } + if (dev->iface->get_protocol_features) { features |=3D dev->iface->get_protocol_features(dev); } --=20 2.13.5