From nobody Wed Oct 29 20:50:48 2025 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 1525462224093920.5959867668403; Fri, 4 May 2018 12:30:24 -0700 (PDT) Received: from localhost ([::1]:36190 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fEgPM-0004p5-91 for importer@patchew.org; Fri, 04 May 2018 15:30:20 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35750) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fEgLU-0001U7-18 for qemu-devel@nongnu.org; Fri, 04 May 2018 15:26:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fEgLP-0006hl-Hw for qemu-devel@nongnu.org; Fri, 04 May 2018 15:26:19 -0400 Received: from smtp03.citrix.com ([162.221.156.55]:53752) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fEgLP-0006gU-9t; Fri, 04 May 2018 15:26:15 -0400 X-IronPort-AV: E=Sophos;i="5.49,363,1520899200"; d="scan'208";a="53727417" From: Paul Durrant To: , , Date: Fri, 4 May 2018 20:26:03 +0100 Message-ID: <1525461967-32174-5-git-send-email-paul.durrant@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1525461967-32174-1-git-send-email-paul.durrant@citrix.com> References: <1525461967-32174-1-git-send-email-paul.durrant@citrix.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 162.221.156.55 Subject: [Qemu-devel] [PATCH v3 4/8] xen_backend: add an emulation of grant copy 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: Anthony Perard , Paul Durrant , Stefano Stabellini 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 Content-Type: text/plain; charset="utf-8" Not all Xen environments support the xengnttab_grant_copy() operation. E.g. where the OS is FreeBSD or Xen is older than 4.8.0. This patch introduces an emulation of that operation using xengnttab_map_domain_grant_refs() and memcpy() for those environments. Signed-off-by: Paul Durrant --- Cc: Stefano Stabellini Cc: Anthony Perard v2: - New in v2 --- hw/xen/xen_backend.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++= ++++ 1 file changed, 53 insertions(+) diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c index 50412d6..3c3fc2c 100644 --- a/hw/xen/xen_backend.c +++ b/hw/xen/xen_backend.c @@ -146,6 +146,55 @@ void xen_be_unmap_grant_refs(struct XenDevice *xendev,= void *ptr, } } =20 +static int compat_copy_grant_refs(struct XenDevice *xendev, + bool to_domain, + XenGrantCopySegment segs[], + unsigned int nr_segs) +{ + uint32_t *refs =3D g_new(uint32_t, nr_segs); + int prot =3D to_domain ? PROT_WRITE : PROT_READ; + void *pages; + unsigned int i; + + for (i =3D 0; i < nr_segs; i++) { + XenGrantCopySegment *seg =3D &segs[i]; + + refs[i] =3D to_domain ? + seg->dest.foreign.ref : seg->source.foreign.ref; + } + + pages =3D xengnttab_map_domain_grant_refs(xendev->gnttabdev, nr_segs, + xen_domid, refs, prot); + if (!pages) { + xen_pv_printf(xendev, 0, + "xengnttab_map_domain_grant_refs failed: %s\n", + strerror(errno)); + g_free(refs); + return -1; + } + + for (i =3D 0; i < nr_segs; i++) { + XenGrantCopySegment *seg =3D &segs[i]; + void *page =3D pages + (i * XC_PAGE_SIZE); + + if (to_domain) { + memcpy(page + seg->dest.foreign.offset, seg->source.virt, + seg->len); + } else { + memcpy(seg->dest.virt, page + seg->source.foreign.offset, + seg->len); + } + } + + if (xengnttab_unmap(xendev->gnttabdev, pages, nr_segs)) { + xen_pv_printf(xendev, 0, "xengnttab_unmap failed: %s\n", + strerror(errno)); + } + + g_free(refs); + return 0; +} + int xen_be_copy_grant_refs(struct XenDevice *xendev, bool to_domain, XenGrantCopySegment segs[], @@ -157,6 +206,10 @@ int xen_be_copy_grant_refs(struct XenDevice *xendev, =20 assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV); =20 + if (!xen_feature_grant_copy) { + return compat_copy_grant_refs(xendev, to_domain, segs, nr_segs); + } + xengnttab_segs =3D g_new0(xengnttab_grant_copy_segment_t, nr_segs); =20 for (i =3D 0; i < nr_segs; i++) { --=20 2.1.4