From nobody Tue Feb 10 05:17:29 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 1516853342307882.4247011995076; Wed, 24 Jan 2018 20:09:02 -0800 (PST) Received: from localhost ([::1]:40553 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eeYqT-0005Mp-IH for importer@patchew.org; Wed, 24 Jan 2018 23:09:01 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40515) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eeYm0-00027u-8c for qemu-devel@nongnu.org; Wed, 24 Jan 2018 23:04:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eeYly-0005Yi-Si for qemu-devel@nongnu.org; Wed, 24 Jan 2018 23:04:24 -0500 Received: from mga14.intel.com ([192.55.52.115]:64671) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eeYly-0005Wb-ID for qemu-devel@nongnu.org; Wed, 24 Jan 2018 23:04:22 -0500 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Jan 2018 20:04:22 -0800 Received: from debian-xvivbkq.sh.intel.com ([10.67.104.226]) by fmsmga001.fm.intel.com with ESMTP; 24 Jan 2018 20:04:20 -0800 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,409,1511856000"; d="scan'208";a="25261360" From: Tiwei Bie To: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, alex.williamson@redhat.com, jasowang@redhat.com, pbonzini@redhat.com, stefanha@redhat.com Date: Thu, 25 Jan 2018 12:03:26 +0800 Message-Id: <20180125040328.22867-5-tiwei.bie@intel.com> X-Mailer: git-send-email 2.13.3 In-Reply-To: <20180125040328.22867-1-tiwei.bie@intel.com> References: <20180125040328.22867-1-tiwei.bie@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.115 Subject: [Qemu-devel] [PATCH v1 4/6] vfio: support getting VFIOGroup from groupfd 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: jianfeng.tan@intel.com, tiwei.bie@intel.com, cunming.liang@intel.com, xiao.w.wang@intel.com, zhihong.wang@intel.com, dan.daly@intel.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" Add an API to support getting VFIOGroup from groupfd. When groupfd is shared by another process, the VFIOGroup may not have its container and address space in QEMU. Besides, add a reference counter to better support getting VFIOGroup multiple times. Signed-off-by: Tiwei Bie --- hw/vfio/common.c | 96 +++++++++++++++++++++++++++++++++++++++= +++- include/hw/vfio/vfio-common.h | 2 + 2 files changed, 97 insertions(+), 1 deletion(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 7b2924c0ef..027fa005c1 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -962,6 +962,11 @@ static int vfio_connect_container(VFIOGroup *group, Ad= dressSpace *as, int ret, fd; VFIOAddressSpace *space; =20 + if (as =3D=3D NULL) { + vfio_kvm_device_add_group(group); + return 0; + } + space =3D vfio_get_address_space(as); =20 QLIST_FOREACH(container, &space->containers, next) { @@ -1153,6 +1158,10 @@ static void vfio_disconnect_container(VFIOGroup *gro= up) { VFIOContainer *container =3D group->container; =20 + if (container =3D=3D NULL) { + return; + } + if (ioctl(group->fd, VFIO_GROUP_UNSET_CONTAINER, &container->fd)) { error_report("vfio: error disconnecting group %d from container", group->groupid); @@ -1183,6 +1192,85 @@ static void vfio_disconnect_container(VFIOGroup *gro= up) } } =20 +static int vfio_groupfd_to_groupid(int groupfd) +{ + char linkname[PATH_MAX]; + char pathname[PATH_MAX]; + char *filename; + int groupid, ret; + + snprintf(linkname, sizeof(linkname), "/proc/self/fd/%d", groupfd); + + ret =3D readlink(linkname, pathname, sizeof(pathname)); + if (ret < 0) { + return -1; + } + + filename =3D g_path_get_basename(pathname); + groupid =3D atoi(filename); + g_free(filename); + + return groupid; +} + +/* + * The @as param could be NULL. In this case, groupfd is shared by + * another process which will setup the DMA mapping for this group, + * and this group won't have container and address space in QEMU. + */ +VFIOGroup *vfio_get_group_from_fd(int groupfd, AddressSpace *as, Error **e= rrp) +{ + VFIOGroup *group; + int groupid; + + groupid =3D vfio_groupfd_to_groupid(groupfd); + if (groupid < 0) { + return NULL; + } + + QLIST_FOREACH(group, &vfio_group_list, next) { + if (group->groupid =3D=3D groupid) { + /* Found it. Now is it already in the right context? */ + if ((group->container =3D=3D NULL && as =3D=3D NULL) || + (group->container && group->container->space->as =3D=3D as= )) { + group->refcnt++; + return group; + } + error_setg(errp, "group %d used in multiple address spaces", + group->groupid); + return NULL; + } + } + + group =3D g_malloc0(sizeof(*group)); + + group->fd =3D groupfd; + group->groupid =3D groupid; + group->refcnt =3D 1; + + QLIST_INIT(&group->device_list); + + if (vfio_connect_container(group, as, errp)) { + error_prepend(errp, "failed to setup container for group %d: ", + groupid); + goto free_group_exit; + } + + if (QLIST_EMPTY(&vfio_group_list)) { + qemu_register_reset(vfio_reset_handler, NULL); + } + + QLIST_INSERT_HEAD(&vfio_group_list, group, next); + + return group; + +free_group_exit: + g_free(group); + + return NULL; +} + +/* The @as param cannot be NULL. */ VFIOGroup *vfio_get_group(int groupid, AddressSpace *as, Error **errp) { VFIOGroup *group; @@ -1192,7 +1280,8 @@ VFIOGroup *vfio_get_group(int groupid, AddressSpace *= as, Error **errp) QLIST_FOREACH(group, &vfio_group_list, next) { if (group->groupid =3D=3D groupid) { /* Found it. Now is it already in the right context? */ - if (group->container->space->as =3D=3D as) { + if (group->container && group->container->space->as =3D=3D as)= { + group->refcnt++; return group; } else { error_setg(errp, "group %d used in multiple address spaces= ", @@ -1225,6 +1314,7 @@ VFIOGroup *vfio_get_group(int groupid, AddressSpace *= as, Error **errp) } =20 group->groupid =3D groupid; + group->refcnt =3D 1; QLIST_INIT(&group->device_list); =20 if (vfio_connect_container(group, as, errp)) { @@ -1256,6 +1346,10 @@ void vfio_put_group(VFIOGroup *group) return; } =20 + if (--group->refcnt > 0) { + return; + } + vfio_kvm_device_del_group(group); vfio_disconnect_container(group); QLIST_REMOVE(group, next); diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index f3a2ac9fee..2383ded670 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -136,6 +136,7 @@ struct VFIODeviceOps { typedef struct VFIOGroup { int fd; int groupid; + int refcnt; VFIOContainer *container; QLIST_HEAD(, VFIODevice) device_list; QLIST_ENTRY(VFIOGroup) next; @@ -158,6 +159,7 @@ void vfio_region_exit(VFIORegion *region); void vfio_region_finalize(VFIORegion *region); void vfio_reset_handler(void *opaque); VFIOGroup *vfio_get_group(int groupid, AddressSpace *as, Error **errp); +VFIOGroup *vfio_get_group_from_fd(int groupfd, AddressSpace *as, Error **e= rrp); void vfio_put_group(VFIOGroup *group); int vfio_get_device(VFIOGroup *group, const char *name, VFIODevice *vbasedev, Error **errp); --=20 2.13.3