1 files changed, 146 insertions, 0 deletions

diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c
index 5e19592190..faa9fd3577 100644
--- a/hw/xen/xen-bus.c
+++ b/hw/xen/xen-bus.c
@@ -485,6 +485,138 @@ static void xen_device_frontend_destroy(XenDevice *xendev)
     }
 }
 
+void xen_device_set_max_grant_refs(XenDevice *xendev, unsigned int nr_refs,
+                                   Error **errp)
+{
+    if (xengnttab_set_max_grants(xendev->xgth, nr_refs)) {
+        error_setg_errno(errp, errno, "xengnttab_set_max_grants failed");
+    }
+}
+
+void *xen_device_map_grant_refs(XenDevice *xendev, uint32_t *refs,
+                                unsigned int nr_refs, int prot,
+                                Error **errp)
+{
+    void *map = xengnttab_map_domain_grant_refs(xendev->xgth, nr_refs,
+                                                xendev->frontend_id, refs,
+                                                prot);
+
+    if (!map) {
+        error_setg_errno(errp, errno,
+                         "xengnttab_map_domain_grant_refs failed");
+    }
+
+    return map;
+}
+
+void xen_device_unmap_grant_refs(XenDevice *xendev, void *map,
+                                 unsigned int nr_refs, Error **errp)
+{
+    if (xengnttab_unmap(xendev->xgth, map, nr_refs)) {
+        error_setg_errno(errp, errno, "xengnttab_unmap failed");
+    }
+}
+
+static void compat_copy_grant_refs(XenDevice *xendev, bool to_domain,
+                                   XenDeviceGrantCopySegment segs[],
+                                   unsigned int nr_segs, Error **errp)
+{
+    uint32_t *refs = g_new(uint32_t, nr_segs);
+    int prot = to_domain ? PROT_WRITE : PROT_READ;
+    void *map;
+    unsigned int i;
+
+    for (i = 0; i < nr_segs; i++) {
+        XenDeviceGrantCopySegment *seg = &segs[i];
+
+        refs[i] = to_domain ? seg->dest.foreign.ref :
+            seg->source.foreign.ref;
+    }
+
+    map = xengnttab_map_domain_grant_refs(xendev->xgth, nr_segs,
+                                          xendev->frontend_id, refs,
+                                          prot);
+    if (!map) {
+        error_setg_errno(errp, errno,
+                         "xengnttab_map_domain_grant_refs failed");
+        goto done;
+    }
+
+    for (i = 0; i < nr_segs; i++) {
+        XenDeviceGrantCopySegment *seg = &segs[i];
+        void *page = map + (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->xgth, map, nr_segs)) {
+        error_setg_errno(errp, errno, "xengnttab_unmap failed");
+    }
+
+done:
+    g_free(refs);
+}
+
+void xen_device_copy_grant_refs(XenDevice *xendev, bool to_domain,
+                                XenDeviceGrantCopySegment segs[],
+                                unsigned int nr_segs, Error **errp)
+{
+    xengnttab_grant_copy_segment_t *xengnttab_segs;
+    unsigned int i;
+
+    if (!xendev->feature_grant_copy) {
+        compat_copy_grant_refs(xendev, to_domain, segs, nr_segs, errp);
+        return;
+    }
+
+    xengnttab_segs = g_new0(xengnttab_grant_copy_segment_t, nr_segs);
+
+    for (i = 0; i < nr_segs; i++) {
+        XenDeviceGrantCopySegment *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 = xendev->frontend_id;
+            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 = xendev->frontend_id;
+            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;
+    }
+
+    if (xengnttab_grant_copy(xendev->xgth, nr_segs, xengnttab_segs)) {
+        error_setg_errno(errp, errno, "xengnttab_grant_copy failed");
+        goto done;
+    }
+
+    for (i = 0; i < nr_segs; i++) {
+        xengnttab_grant_copy_segment_t *xengnttab_seg = &xengnttab_segs[i];
+
+        if (xengnttab_seg->status != GNTST_okay) {
+            error_setg(errp, "xengnttab_grant_copy seg[%u] failed", i);
+            break;
+        }
+    }
+
+done:
+    g_free(xengnttab_segs);
+}
+
 static void xen_device_unrealize(DeviceState *dev, Error **errp)
 {
     XenDevice *xendev = XEN_DEVICE(dev);
@@ -509,6 +641,11 @@ static void xen_device_unrealize(DeviceState *dev, Error **errp)
     xen_device_frontend_destroy(xendev);
     xen_device_backend_destroy(xendev);
 
+    if (xendev->xgth) {
+        xengnttab_close(xendev->xgth);
+        xendev->xgth = NULL;
+    }
+
     g_free(xendev->name);
     xendev->name = NULL;
 }
@@ -551,6 +688,15 @@ static void xen_device_realize(DeviceState *dev, Error **errp)
 
     trace_xen_device_realize(type, xendev->name);
 
+    xendev->xgth = xengnttab_open(NULL, 0);
+    if (!xendev->xgth) {
+        error_setg_errno(errp, errno, "failed xengnttab_open");
+        goto unrealize;
+    }
+
+    xendev->feature_grant_copy =
+        (xengnttab_grant_copy(xendev->xgth, 0, NULL) == 0);
+
     xen_device_backend_create(xendev, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);