From patchwork Fri May 4 13:55:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 908738 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=none (p=none dis=none) header.from=citrix.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 40ctt62zFHz9s4t for ; Fri, 4 May 2018 23:59:26 +1000 (AEST) Received: from localhost ([::1]:34542 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fEbF5-0007U7-VJ for incoming@patchwork.ozlabs.org; Fri, 04 May 2018 09:59:24 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50410) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fEbBk-0004wj-BT for qemu-devel@nongnu.org; Fri, 04 May 2018 09:55:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fEbBg-0003RI-7m for qemu-devel@nongnu.org; Fri, 04 May 2018 09:55:56 -0400 Received: from smtp03.citrix.com ([162.221.156.55]:24318) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fEbBf-0003Qa-S8; Fri, 04 May 2018 09:55:52 -0400 X-IronPort-AV: E=Sophos;i="5.49,362,1520899200"; d="scan'208";a="53691024" From: Paul Durrant To: , , Date: Fri, 4 May 2018 14:55:27 +0100 Message-ID: <1525442134-20488-2-git-send-email-paul.durrant@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1525442134-20488-1-git-send-email-paul.durrant@citrix.com> References: <1525442134-20488-1-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 v2 1/8] 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 --- 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 xenbus_state state) return 0; } +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 = 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 = g_new0(xengnttab_grant_copy_segment_t, nr_segs); + + for (i = 0; i < nr_segs; i++) { + XenGrantCopySegment *seg = &segs[i]; + xengnttab_grant_copy_segment_t *xengnttab_seg = &xengnttab_segs[i]; + + if (to_domain) { + xengnttab_seg->flags = GNTCOPY_dest_gref; + xengnttab_seg->dest.foreign.domid = xen_domid; + xengnttab_seg->dest.foreign.ref = seg->dest.foreign.ref; + xengnttab_seg->dest.foreign.offset = seg->dest.foreign.offset; + xengnttab_seg->source.virt = seg->source.virt; + } else { + xengnttab_seg->flags = GNTCOPY_source_gref; + xengnttab_seg->source.foreign.domid = xen_domid; + xengnttab_seg->source.foreign.ref = seg->source.foreign.ref; + xengnttab_seg->source.foreign.offset = + seg->source.foreign.offset; + xengnttab_seg->dest.virt = seg->dest.virt; + } + + xengnttab_seg->len = seg->len; + } + + rc = 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 = 0; i < nr_segs; i++) { + xengnttab_grant_copy_segment_t *xengnttab_seg = + &xengnttab_segs[i]; + + if (xengnttab_seg->status != GNTST_okay) { + xen_pv_printf(xendev, 0, "segment[%u] status: %d\n", i, + xengnttab_seg->status); + rc = -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)); - if (ops->flags & DEVOPS_FLAG_NEED_GNTDEV) { - xendev->gnttabdev = xengnttab_open(NULL, 0); - if (xendev->gnttabdev == 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 = NULL; - } - xen_pv_insert_xendev(xendev); if (xendev->ops->alloc) { @@ -322,6 +407,16 @@ static int xen_be_try_initialise(struct XenDevice *xendev) } } + if (xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV) { + xendev->gnttabdev = xengnttab_open(NULL, 0); + if (xendev->gnttabdev == NULL) { + xen_pv_printf(NULL, 0, "can't open gnttab device\n"); + return -1; + } + } else { + xendev->gnttabdev = NULL; + } + if (xendev->ops->initialise) { rc = 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 = NULL; + } if (xendev->be_state != 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); +} /* actual backend drivers */ extern struct XenDevOps xen_console_ops; /* xen_console.c */