From patchwork Tue Jan 5 11:41:34 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerd Hoffmann X-Patchwork-Id: 7954211 Return-Path: X-Original-To: patchwork-xen-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 9FC33BEEE5 for ; Tue, 5 Jan 2016 11:45:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C43CF20396 for ; Tue, 5 Jan 2016 11:45:08 +0000 (UTC) Received: from lists.xen.org (lists.xenproject.org [50.57.142.19]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D446520166 for ; Tue, 5 Jan 2016 11:45:07 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aGQ09-0004iQ-Lf; Tue, 05 Jan 2016 11:42:09 +0000 Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aGQ05-0004fo-CN for xen-devel@lists.xensource.com; Tue, 05 Jan 2016 11:42:05 +0000 Received: from [193.109.254.147] by server-14.bemta-14.messagelabs.com id FD/A5-07165-C0CAB865; Tue, 05 Jan 2016 11:42:04 +0000 X-Env-Sender: kraxel@redhat.com X-Msg-Ref: server-4.tower-27.messagelabs.com!1451994121!13841121!1 X-Originating-IP: [209.132.183.28] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogMjA5LjEzMi4xODMuMjggPT4gNTQwNjQ=\n X-StarScan-Received: X-StarScan-Version: 7.35.1; banners=-,-,- X-VirusChecked: Checked Received: (qmail 5818 invoked from network); 5 Jan 2016 11:42:03 -0000 Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by server-4.tower-27.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 5 Jan 2016 11:42:03 -0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 9CB4EC0A8046; Tue, 5 Jan 2016 11:42:01 +0000 (UTC) Received: from nilsson.home.kraxel.org (ovpn-116-22.ams2.redhat.com [10.36.116.22]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u05BfxFK012474; Tue, 5 Jan 2016 06:42:00 -0500 Received: by nilsson.home.kraxel.org (Postfix, from userid 500) id 9F30480DDC; Tue, 5 Jan 2016 12:41:57 +0100 (CET) From: Gerd Hoffmann To: qemu-devel@nongnu.org Date: Tue, 5 Jan 2016 12:41:34 +0100 Message-Id: <1451994098-6972-8-git-send-email-kraxel@redhat.com> In-Reply-To: <1451994098-6972-1-git-send-email-kraxel@redhat.com> References: <1451994098-6972-1-git-send-email-kraxel@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 Cc: igvt-g@ml01.01.org, xen-devel@lists.xensource.com, Eduardo Habkost , Stefano Stabellini , Cao jin , vfio-users@redhat.com, Gerd Hoffmann Subject: [Xen-devel] [PATCH v3 07/11] igd: revamp host config read X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable 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 Move all work to the host_pci_config_copy helper function, which we can easily reuse when adding q35 support. Open sysfs file only once for all values. Use pread. Proper error handling. Fix bugs: * Don't throw away results (like old host_pci_config_read did because val was passed by value not reference). * Update config space directly (writing via pci_default_write_config only works for registers whitelisted in wmask). Hmm, this code can hardly ever worked before, /me wonders what test coverage it had. With this patch in place igd-passthru=on actually works, although it still requires root priviledges because linux refuses to allow non-root users access pci config space above offset 0x50. Signed-off-by: Gerd Hoffmann --- hw/pci-host/igd.c | 65 +++++++++++++++++++++++-------------------------------- 1 file changed, 27 insertions(+), 38 deletions(-) diff --git a/hw/pci-host/igd.c b/hw/pci-host/igd.c index 0784128..ec48875 100644 --- a/hw/pci-host/igd.c +++ b/hw/pci-host/igd.c @@ -19,47 +19,39 @@ static const IGDHostInfo igd_host_bridge_infos[] = { {0xa8, 4}, /* SNB: base of GTT stolen memory */ }; -static int host_pci_config_read(int pos, int len, uint32_t val) +static void host_pci_config_copy(PCIDevice *guest, const char *host, + const IGDHostInfo *list, int len, Error **errp) { - char path[PATH_MAX]; - int config_fd; - ssize_t size = sizeof(path); - /* Access real host bridge. */ - int rc = snprintf(path, size, "/sys/bus/pci/devices/%04x:%02x:%02x.%d/%s", - 0, 0, 0, 0, "config"); - int ret = 0; + char *path; + int config_fd, rc, i; - if (rc >= size || rc < 0) { - return -ENODEV; - } - - config_fd = open(path, O_RDWR); + path = g_strdup_printf("/sys/bus/pci/devices/%s/config", host); + config_fd = open(path, O_RDONLY); if (config_fd < 0) { - return -ENODEV; + error_setg_file_open(errp, errno, path); + goto out_free; } - if (lseek(config_fd, pos, SEEK_SET) != pos) { - ret = -errno; - goto out; + for (i = 0; i < len; i++) { + rc = pread(config_fd, guest->config + list[i].offset, + list[i].len, list[i].offset); + if (rc != list[i].len) { + error_setg_errno(errp, errno, "read %s, offset 0x%x", + path, list[i].offset); + goto out_close; + } } - do { - rc = read(config_fd, (uint8_t *)&val, len); - } while (rc < 0 && (errno == EINTR || errno == EAGAIN)); - if (rc != len) { - ret = -errno; - } -out: + +out_close: close(config_fd); - return ret; +out_free: + g_free(path); } static void (*i440fx_realize)(PCIDevice *pci_dev, Error **errp); static void igd_pt_i440fx_realize(PCIDevice *pci_dev, Error **errp) { Error *err = NULL; - uint32_t val = 0; - int rc, i, num; - int pos, len; i440fx_realize(pci_dev, &err); if (err != NULL) { @@ -67,16 +59,13 @@ static void igd_pt_i440fx_realize(PCIDevice *pci_dev, Error **errp) return; } - num = ARRAY_SIZE(igd_host_bridge_infos); - for (i = 0; i < num; i++) { - pos = igd_host_bridge_infos[i].offset; - len = igd_host_bridge_infos[i].len; - rc = host_pci_config_read(pos, len, val); - if (rc) { - error_setg(errp, "failed to read host config"); - return; - } - pci_default_write_config(pci_dev, pos, val, len); + host_pci_config_copy(pci_dev, "0000:00:00.0", + igd_host_bridge_infos, + ARRAY_SIZE(igd_host_bridge_infos), + &err); + if (err != NULL) { + error_propagate(errp, err); + return; } }