From patchwork Mon Jul 23 04:59:55 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiwei Bie X-Patchwork-Id: 947608 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 41Yq8F5G7Rz9s1x for ; Mon, 23 Jul 2018 15:01:17 +1000 (AEST) Received: from localhost ([::1]:32779 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fhSyB-0003rd-C2 for incoming@patchwork.ozlabs.org; Mon, 23 Jul 2018 01:01:15 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43748) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fhSxa-0003lL-Hv for qemu-devel@nongnu.org; Mon, 23 Jul 2018 01:00:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fhSxX-00050j-8q for qemu-devel@nongnu.org; Mon, 23 Jul 2018 01:00:38 -0400 Received: from mga07.intel.com ([134.134.136.100]:45043) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fhSxW-0004yY-V6 for qemu-devel@nongnu.org; Mon, 23 Jul 2018 01:00:35 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Jul 2018 22:00:33 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,392,1526367600"; d="scan'208";a="59837285" Received: from debian.sh.intel.com ([10.67.104.228]) by orsmga006.jf.intel.com with ESMTP; 22 Jul 2018 22:00:19 -0700 From: Tiwei Bie To: mst@redhat.com, alex.williamson@redhat.com, jasowang@redhat.com, qemu-devel@nongnu.org Date: Mon, 23 Jul 2018 12:59:55 +0800 Message-Id: <20180723045956.27521-3-tiwei.bie@intel.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180723045956.27521-1-tiwei.bie@intel.com> References: <20180723045956.27521-1-tiwei.bie@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.100 Subject: [Qemu-devel] [RFC 2/3] 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: tiwei.bie@intel.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" This patch introduces an API to support getting VFIOGroup from groupfd. This is useful when the groupfd is opened and shared by another process via UNIX socket. Signed-off-by: Tiwei Bie --- hw/vfio/common.c | 44 +++++++++++++++++++++++++++++++++++ include/hw/vfio/vfio-common.h | 1 + 2 files changed, 45 insertions(+) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 52a05532cd..4c19a33dd5 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1279,6 +1279,30 @@ static void vfio_disconnect_container(VFIOGroup *group) } } +static int vfio_groupfd_to_groupid(int groupfd) +{ + char *tmp, group_path[PATH_MAX], *group_name; + int groupid, len; + + tmp = g_strdup_printf("/proc/self/fd/%d", groupfd); + len = readlink(tmp, group_path, sizeof(group_path)); + g_free(tmp); + + if (len <= 0 || len >= sizeof(group_path)) { + return -1; + } + + group_path[len] = '\0'; + + group_name = g_path_get_basename(group_path); + if (sscanf(group_name, "%d", &groupid) != 1) { + groupid = -1; + } + g_free(group_name); + + return groupid; +} + static VFIOGroup *vfio_init_group(int groupfd, int groupid, AddressSpace *as, Error **errp) { @@ -1373,6 +1397,26 @@ VFIOGroup *vfio_get_group(int groupid, AddressSpace *as, Error **errp) return group; } +VFIOGroup *vfio_get_group_from_fd(int groupfd, AddressSpace *as, Error **errp) +{ + VFIOGroup *group; + int groupid; + + groupid = vfio_groupfd_to_groupid(groupfd); + if (groupid < 0) { + error_setg(errp, "failed to get group id from group fd %d", + groupfd); + return NULL; + } + + group = vfio_find_group(groupid, as, errp); + if (group) { + return group; + } + + return vfio_init_group(groupfd, groupid, as, errp); +} + void vfio_put_group(VFIOGroup *group) { if (!group || !QLIST_EMPTY(&group->device_list)) { diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index a9036929b2..9bb1068a36 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -170,6 +170,7 @@ 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 **errp); void vfio_put_group(VFIOGroup *group); int vfio_get_device(VFIOGroup *group, const char *name, VFIODevice *vbasedev, Error **errp);