From patchwork Tue Mar 8 02:10:23 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 8528581 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 9D045C0553 for ; Tue, 8 Mar 2016 02:22:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CF9092015A for ; Tue, 8 Mar 2016 02:22:19 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0E0CC20155 for ; Tue, 8 Mar 2016 02:22:19 +0000 (UTC) Received: from localhost ([::1]:59641 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ad7Hu-0002w0-Cx for patchwork-qemu-devel@patchwork.kernel.org; Mon, 07 Mar 2016 21:22:18 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58514) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ad7He-0002tf-10 for qemu-devel@nongnu.org; Mon, 07 Mar 2016 21:22:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ad7Hc-0002Tc-Md for qemu-devel@nongnu.org; Mon, 07 Mar 2016 21:22:01 -0500 Received: from ozlabs.org ([2401:3900:2:1::2]:48422) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ad7Hc-0002T3-22; Mon, 07 Mar 2016 21:22:00 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 82594140B0D; Tue, 8 Mar 2016 13:21:56 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1457403716; bh=Mdwm/hUHb02p1ydCYde1kreGzc7SPHpm/Q/I37aRDDo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cp/ZguMGlwE6rqhC7Ez+h/f0qunFtW9BiRqCZs4pKv2FTKgUpB4ydNajTjE8zbKpw +Wa/VaOxO0NNEuvalnkGM/wj8BtdxbYgv5ICWotxDahTYSEIsxIlRR0hM3Vo2TEMhH hxYtzEibfWogHBxMSNyIDGlDWopiZ2egTmRvFoG8= From: David Gibson To: aik@ozlabs.ru, alex.williamson@redhat.com Date: Tue, 8 Mar 2016 13:10:23 +1100 Message-Id: <1457403029-21322-2-git-send-email-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1457403029-21322-1-git-send-email-david@gibson.dropbear.id.au> References: <1457403029-21322-1-git-send-email-david@gibson.dropbear.id.au> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2401:3900:2:1::2 Cc: agraf@suse.de, gwshan@au1.ibm.com, qemu-devel@nongnu.org, qemu-ppc@nongnu.org, David Gibson Subject: [Qemu-devel] [PATCHv3 1/7] vfio: Start improving VFIO/EEH interface X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP At present the code handling IBM's Enhanced Error Handling (EEH) interface on VFIO devices operates by bypassing the usual VFIO logic with vfio_container_ioctl(). That's a poorly designed interface with unclear semantics about exactly what can be operated on. In particular it operates on a single vfio container internally (hence the name), but takes an address space and group id, from which it deduces the container in a rather roundabout way. groupids are something that code outside vfio shouldn't even be aware of. This patch creates new interfaces for EEH operations. Internally we have vfio_eeh_container_op() which takes a VFIOContainer object directly. For external use we have vfio_eeh_as_ok() which determines if an AddressSpace is usable for EEH (at present this means it has a single container with exactly one group attached), and vfio_eeh_as_op() which will perform an operation on an AddressSpace in the unambiguous case, and otherwise returns an error. This interface still isn't great, but it's enough of an improvement to allow a number of cleanups in other places. Signed-off-by: David Gibson Reviewed-by: Alexey Kardashevskiy Acked-by: Alex Williamson --- hw/vfio/common.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++ include/hw/vfio/vfio.h | 2 ++ 2 files changed, 97 insertions(+) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 96ccb79..0636bb1 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1137,3 +1137,98 @@ int vfio_container_ioctl(AddressSpace *as, int32_t groupid, return vfio_container_do_ioctl(as, groupid, req, param); } + +/* + * Interfaces for IBM EEH (Enhanced Error Handling) + */ +static bool vfio_eeh_container_ok(VFIOContainer *container) +{ + /* + * As of 2016-03-04 (linux-4.5) the host kernel EEH/VFIO + * implementation is broken if there are multiple groups in a + * container. The hardware works in units of Partitionable + * Endpoints (== IOMMU groups) and the EEH operations naively + * iterate across all groups in the container, without any logic + * to make sure the groups have their state synchronized. For + * certain operations (ENABLE) that might be ok, until an error + * occurs, but for others (GET_STATE) it's clearly broken. + */ + + /* + * XXX Once fixed kernels exist, test for them here + */ + + if (QLIST_EMPTY(&container->group_list)) { + return false; + } + + if (QLIST_NEXT(QLIST_FIRST(&container->group_list), container_next)) { + return false; + } + + return true; +} + +static int vfio_eeh_container_op(VFIOContainer *container, uint32_t op) +{ + struct vfio_eeh_pe_op pe_op = { + .argsz = sizeof(pe_op), + .op = op, + }; + int ret; + + if (!vfio_eeh_container_ok(container)) { + error_report("vfio/eeh: EEH_PE_OP 0x%x: " + "kernel requires a container with exactly one group", op); + return -EPERM; + } + + ret = ioctl(container->fd, VFIO_EEH_PE_OP, &pe_op); + if (ret < 0) { + error_report("vfio/eeh: EEH_PE_OP 0x%x failed: %m", op); + return -errno; + } + + return 0; +} + +static VFIOContainer *vfio_eeh_as_container(AddressSpace *as) +{ + VFIOAddressSpace *space = vfio_get_address_space(as); + VFIOContainer *container = NULL; + + if (QLIST_EMPTY(&space->containers)) { + /* No containers to act on */ + goto out; + } + + container = QLIST_FIRST(&space->containers); + + if (QLIST_NEXT(container, next)) { + /* We don't yet have logic to synchronize EEH state across + * multiple containers */ + container = NULL; + goto out; + } + +out: + vfio_put_address_space(space); + return container; +} + +bool vfio_eeh_as_ok(AddressSpace *as) +{ + VFIOContainer *container = vfio_eeh_as_container(as); + + return (container != NULL) && vfio_eeh_container_ok(container); +} + +int vfio_eeh_as_op(AddressSpace *as, uint32_t op) +{ + VFIOContainer *container = vfio_eeh_as_container(as); + + if (!container) { + return -ENODEV; + } + return vfio_eeh_container_op(container, op); +} diff --git a/include/hw/vfio/vfio.h b/include/hw/vfio/vfio.h index 0b26cd8..fd3933b 100644 --- a/include/hw/vfio/vfio.h +++ b/include/hw/vfio/vfio.h @@ -5,5 +5,7 @@ extern int vfio_container_ioctl(AddressSpace *as, int32_t groupid, int req, void *param); +bool vfio_eeh_as_ok(AddressSpace *as); +int vfio_eeh_as_op(AddressSpace *as, uint32_t op); #endif