From nobody Wed Oct 29 20:39:00 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 1526571752614387.541931740201; Thu, 17 May 2018 08:42:32 -0700 (PDT) Received: from localhost ([::1]:33015 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJL2z-00024Y-PT for importer@patchew.org; Thu, 17 May 2018 11:42:29 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50511) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJKwx-0005Fq-V3 for qemu-devel@nongnu.org; Thu, 17 May 2018 11:36:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fJKwt-0006TI-6Q for qemu-devel@nongnu.org; Thu, 17 May 2018 11:36:15 -0400 Received: from smtp03.citrix.com ([162.221.156.55]:38427) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fJKws-0006SY-MX; Thu, 17 May 2018 11:36:11 -0400 X-IronPort-AV: E=Sophos;i="5.49,411,1520899200"; d="scan'208";a="54916629" From: Paul Durrant To: , , Date: Thu, 17 May 2018 16:35:51 +0100 Message-ID: <1526571358-26685-3-git-send-email-paul.durrant@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1526571358-26685-1-git-send-email-paul.durrant@citrix.com> References: <1526571358-26685-1-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 v4 2/9] xen_backend: add grant table helpers 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" This patch adds grant table helper functions to the xen_backend code to localize error reporting and use of xen_domid. The patch also defers the call to xengnttab_open() until just before the initialise method in XenDevOps is invoked. This method is responsible for mapping the shared ring. No prior method requires access to the grant table. Signed-off-by: Paul Durrant Reviewed-by: Anthony PERARD --- Cc: Stefano Stabellini Cc: Anthony Perard v2: - New in v2 --- hw/xen/xen_backend.c | 123 ++++++++++++++++++++++++++++++++++++++-= ---- include/hw/xen/xen_backend.h | 33 ++++++++++++ 2 files changed, 144 insertions(+), 12 deletions(-) diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c index 7445b50..50412d6 100644 --- a/hw/xen/xen_backend.c +++ b/hw/xen/xen_backend.c @@ -106,6 +106,103 @@ int xen_be_set_state(struct XenDevice *xendev, enum x= enbus_state state) return 0; } =20 +void xen_be_set_max_grant_refs(struct XenDevice *xendev, + unsigned int nr_refs) +{ + assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV); + + if (xengnttab_set_max_grants(xendev->gnttabdev, nr_refs)) { + xen_pv_printf(xendev, 0, "xengnttab_set_max_grants failed: %s\n", + strerror(errno)); + } +} + +void *xen_be_map_grant_refs(struct XenDevice *xendev, uint32_t *refs, + unsigned int nr_refs, int prot) +{ + void *ptr; + + assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV); + + ptr =3D xengnttab_map_domain_grant_refs(xendev->gnttabdev, nr_refs, + xen_domid, refs, prot); + if (!ptr) { + xen_pv_printf(xendev, 0, + "xengnttab_map_domain_grant_refs failed: %s\n", + strerror(errno)); + } + + return ptr; +} + +void xen_be_unmap_grant_refs(struct XenDevice *xendev, void *ptr, + unsigned int nr_refs) +{ + assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV); + + if (xengnttab_unmap(xendev->gnttabdev, ptr, nr_refs)) { + xen_pv_printf(xendev, 0, "xengnttab_unmap failed: %s\n", + strerror(errno)); + } +} + +int xen_be_copy_grant_refs(struct XenDevice *xendev, + bool to_domain, + XenGrantCopySegment segs[], + unsigned int nr_segs) +{ + xengnttab_grant_copy_segment_t *xengnttab_segs; + unsigned int i; + int rc; + + assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV); + + xengnttab_segs =3D g_new0(xengnttab_grant_copy_segment_t, nr_segs); + + for (i =3D 0; i < nr_segs; i++) { + XenGrantCopySegment *seg =3D &segs[i]; + xengnttab_grant_copy_segment_t *xengnttab_seg =3D &xengnttab_segs[= i]; + + if (to_domain) { + xengnttab_seg->flags =3D GNTCOPY_dest_gref; + xengnttab_seg->dest.foreign.domid =3D xen_domid; + xengnttab_seg->dest.foreign.ref =3D seg->dest.foreign.ref; + xengnttab_seg->dest.foreign.offset =3D seg->dest.foreign.offse= t; + xengnttab_seg->source.virt =3D seg->source.virt; + } else { + xengnttab_seg->flags =3D GNTCOPY_source_gref; + xengnttab_seg->source.foreign.domid =3D xen_domid; + xengnttab_seg->source.foreign.ref =3D seg->source.foreign.ref; + xengnttab_seg->source.foreign.offset =3D + seg->source.foreign.offset; + xengnttab_seg->dest.virt =3D seg->dest.virt; + } + + xengnttab_seg->len =3D seg->len; + } + + rc =3D xengnttab_grant_copy(xendev->gnttabdev, nr_segs, xengnttab_segs= ); + + if (rc) { + xen_pv_printf(xendev, 0, "xengnttab_copy failed: %s\n", + strerror(errno)); + } + + for (i =3D 0; i < nr_segs; i++) { + xengnttab_grant_copy_segment_t *xengnttab_seg =3D + &xengnttab_segs[i]; + + if (xengnttab_seg->status !=3D GNTST_okay) { + xen_pv_printf(xendev, 0, "segment[%u] status: %d\n", i, + xengnttab_seg->status); + rc =3D -1; + } + } + + g_free(xengnttab_segs); + return rc; +} + /* * get xen backend device, allocate a new one if it doesn't exist. */ @@ -149,18 +246,6 @@ static struct XenDevice *xen_be_get_xendev(const char = *type, int dom, int dev, } qemu_set_cloexec(xenevtchn_fd(xendev->evtchndev)); =20 - if (ops->flags & DEVOPS_FLAG_NEED_GNTDEV) { - xendev->gnttabdev =3D xengnttab_open(NULL, 0); - if (xendev->gnttabdev =3D=3D NULL) { - xen_pv_printf(NULL, 0, "can't open gnttab device\n"); - xenevtchn_close(xendev->evtchndev); - qdev_unplug(DEVICE(xendev), NULL); - return NULL; - } - } else { - xendev->gnttabdev =3D NULL; - } - xen_pv_insert_xendev(xendev); =20 if (xendev->ops->alloc) { @@ -322,6 +407,16 @@ static int xen_be_try_initialise(struct XenDevice *xen= dev) } } =20 + if (xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV) { + xendev->gnttabdev =3D xengnttab_open(NULL, 0); + if (xendev->gnttabdev =3D=3D NULL) { + xen_pv_printf(NULL, 0, "can't open gnttab device\n"); + return -1; + } + } else { + xendev->gnttabdev =3D NULL; + } + if (xendev->ops->initialise) { rc =3D xendev->ops->initialise(xendev); } @@ -369,6 +464,10 @@ static void xen_be_disconnect(struct XenDevice *xendev= , enum xenbus_state state) xendev->ops->disconnect) { xendev->ops->disconnect(xendev); } + if (xendev->gnttabdev) { + xengnttab_close(xendev->gnttabdev); + xendev->gnttabdev =3D NULL; + } if (xendev->be_state !=3D state) { xen_be_set_state(xendev, state); } diff --git a/include/hw/xen/xen_backend.h b/include/hw/xen/xen_backend.h index 3a27692..29bf1c3 100644 --- a/include/hw/xen/xen_backend.h +++ b/include/hw/xen/xen_backend.h @@ -42,6 +42,39 @@ void xen_be_register_common(void); int xen_be_register(const char *type, struct XenDevOps *ops); int xen_be_set_state(struct XenDevice *xendev, enum xenbus_state state); int xen_be_bind_evtchn(struct XenDevice *xendev); +void xen_be_set_max_grant_refs(struct XenDevice *xendev, + unsigned int nr_refs); +void *xen_be_map_grant_refs(struct XenDevice *xendev, uint32_t *refs, + unsigned int nr_refs, int prot); +void xen_be_unmap_grant_refs(struct XenDevice *xendev, void *ptr, + unsigned int nr_refs); + +typedef struct XenGrantCopySegment { + union { + void *virt; + struct { + uint32_t ref; + off_t offset; + } foreign; + } source, dest; + size_t len; +} XenGrantCopySegment; + +int xen_be_copy_grant_refs(struct XenDevice *xendev, + bool to_domain, XenGrantCopySegment segs[], + unsigned int nr_segs); + +static inline void *xen_be_map_grant_ref(struct XenDevice *xendev, + uint32_t ref, int prot) +{ + return xen_be_map_grant_refs(xendev, &ref, 1, prot); +} + +static inline void xen_be_unmap_grant_ref(struct XenDevice *xendev, + void *ptr) +{ + return xen_be_unmap_grant_refs(xendev, ptr, 1); +} =20 /* actual backend drivers */ extern struct XenDevOps xen_console_ops; /* xen_console.c */ --=20 2.1.4