@@ -5,6 +5,7 @@ common-obj-$(CONFIG_TPM) += tpm.o
common-obj-y += hostmem.o hostmem-ram.o
common-obj-$(CONFIG_LINUX) += hostmem-file.o
+common-obj-${CONFIG_XEN_BACKEND} += hostmem-xen.o
common-obj-y += cryptodev.o
common-obj-y += cryptodev-builtin.o
new file mode 100644
@@ -0,0 +1,108 @@
+/*
+ * QEMU Host Memory Backend for Xen
+ *
+ * Copyright(C) 2017 Intel Corporation.
+ *
+ * Author:
+ * Haozhong Zhang <haozhong.zhang@intel.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>
+ */
+
+#include "qemu/osdep.h"
+#include "sysemu/hostmem.h"
+#include "qapi/error.h"
+#include "qom/object_interfaces.h"
+
+#define TYPE_MEMORY_BACKEND_XEN "memory-backend-xen"
+
+#define MEMORY_BACKEND_XEN(obj) \
+ OBJECT_CHECK(HostMemoryBackendXen, (obj), TYPE_MEMORY_BACKEND_XEN)
+
+typedef struct HostMemoryBackendXen HostMemoryBackendXen;
+
+struct HostMemoryBackendXen {
+ HostMemoryBackend parent_obj;
+
+ uint64_t host_addr;
+};
+
+static void xen_backend_get_host_addr(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ HostMemoryBackendXen *backend = MEMORY_BACKEND_XEN(obj);
+ uint64_t value = backend->host_addr;
+
+ visit_type_size(v, name, &value, errp);
+}
+
+static void xen_backend_set_host_addr(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ HostMemoryBackend *backend = MEMORY_BACKEND(obj);
+ HostMemoryBackendXen *xb = MEMORY_BACKEND_XEN(obj);
+ Error *local_err = NULL;
+ uint64_t value;
+
+ if (memory_region_size(&backend->mr)) {
+ error_setg(&local_err, "cannot change property value");
+ goto out;
+ }
+
+ visit_type_size(v, name, &value, &local_err);
+ if (local_err) {
+ goto out;
+ }
+ xb->host_addr = value;
+
+ out:
+ error_propagate(errp, local_err);
+}
+
+static void xen_backend_alloc(HostMemoryBackend *backend, Error **errp)
+{
+ if (!backend->size) {
+ error_setg(errp, "can't create backend with size 0");
+ return;
+ }
+ memory_region_init(&backend->mr, OBJECT(backend), "hostmem-xen",
+ backend->size);
+ backend->mr.align = getpagesize();
+}
+
+static void xen_backend_class_init(ObjectClass *oc, void *data)
+{
+ HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
+
+ bc->alloc = xen_backend_alloc;
+
+ object_class_property_add(oc, "host-addr", "int",
+ xen_backend_get_host_addr,
+ xen_backend_set_host_addr,
+ NULL, NULL, &error_abort);
+}
+
+static const TypeInfo xen_backend_info = {
+ .name = TYPE_MEMORY_BACKEND_XEN,
+ .parent = TYPE_MEMORY_BACKEND,
+ .class_init = xen_backend_class_init,
+ .instance_size = sizeof(HostMemoryBackendXen),
+};
+
+static void register_types(void)
+{
+ type_register_static(&xen_backend_info);
+}
+
+type_init(register_types);
@@ -12,6 +12,7 @@
#include "qemu/osdep.h"
#include "sysemu/hostmem.h"
#include "hw/boards.h"
+#include "hw/xen/xen.h"
#include "qapi/error.h"
#include "qapi/visitor.h"
#include "qapi-types.h"
@@ -277,6 +278,14 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
goto out;
}
+ /*
+ * The backend storage of MEMORY_BACKEND_XEN is managed by Xen,
+ * so no further work in this function is needed.
+ */
+ if (xen_enabled() && !backend->mr.ram_block) {
+ goto out;
+ }
+
ptr = memory_region_get_ram_ptr(&backend->mr);
sz = memory_region_size(&backend->mr);
@@ -28,6 +28,7 @@
#include "sysemu/kvm.h"
#include "trace.h"
#include "hw/virtio/vhost.h"
+#include "hw/xen/xen.h"
typedef struct pc_dimms_capacity {
uint64_t size;
@@ -108,7 +109,10 @@ void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
}
memory_region_add_subregion(&hpms->mr, addr - hpms->base, mr);
- vmstate_register_ram(vmstate_mr, dev);
+ /* memory-backend-xen is not backed by RAM. */
+ if (!xen_enabled()) {
+ vmstate_register_ram(vmstate_mr, dev);
+ }
numa_set_mem_node_id(addr, memory_region_size(mr), dimm->node);
out:
vNVDIMM requires a host memory backend to allocate its backend resources to the guest. When QEMU is used as Xen device model, the backend resource allocation of vNVDIMM is managed out of QEMU. A new host memory backend 'memory-backend-xen' is introduced to represent the backend resource allocated by Xen. It simply creates a memory region of the specified size as a placeholder in the guest address space, which will be mapped by Xen to the actual backend resource. Following example QEMU options create a vNVDIMM device backed by a 4GB host PMEM region at host physical address 0x100000000: -object memory-backend-xen,id=mem1,host-addr=0x100000000,size=4G -device nvdimm,id=nvdimm1,memdev=mem1 Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> --- Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> --- backends/Makefile.objs | 1 + backends/hostmem-xen.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++++ backends/hostmem.c | 9 +++++ hw/mem/pc-dimm.c | 6 ++- 4 files changed, 123 insertions(+), 1 deletion(-) create mode 100644 backends/hostmem-xen.c