libxl: allow the creation of HVM domains without a device model.

Replace the firmware loaded into HVM guests with an OS kernel. Since the HVM
builder now uses the PV xc_dom_* set of functions this kernel will be parsed
and loaded inside the guest like on PV, but the container is a pure HVM
guest.

Also, if device_model_version is set to none or a device model for the
specified domain is not present unconditinally set the nic type to
LIBXL_NIC_TYPE_VIF.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>

diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
index 3b695bd40603f21cfdd538ce85d19df1412353ba..8899f7568d25c5c3a5d8fbdd209169e76742660d 100644 (file)
--- a/docs/man/xl.cfg.pod.5
+++ b/docs/man/xl.cfg.pod.5
@@ -1789,6 +1789,11 @@ This device-model is the default for Linux dom0.
 Use the device-model based upon the historical Xen fork of Qemu.
 This device-model is still the default for NetBSD dom0.
 
+=item B<none>
+
+Don't use any device model. This requires a kernel capable of booting
+without emulated devices.
+
 =back
 
 It is recommended to accept the default value for new guests.  If

diff --git a/tools/libxc/include/xc_dom.h b/tools/libxc/include/xc_dom.h
index efa6c6ed8f366b8029c1c5a7200955afb65528fb..2460818ca5ae34d9397b384b4c76526ad9d12e50 100644 (file)
--- a/tools/libxc/include/xc_dom.h
+++ b/tools/libxc/include/xc_dom.h
@@ -20,6 +20,8 @@
 #include <xenguest.h>
 
 #define INVALID_PFN ((xen_pfn_t)-1)
+#define X86_HVM_NR_SPECIAL_PAGES    8
+#define X86_HVM_END_SPECIAL_REGION  0xff000u
 
 /* --- typedefs and structs ---------------------------------------- */
 

diff --git a/tools/libxc/xc_dom_x86.c b/tools/libxc/xc_dom_x86.c
index d05894984cec354c53cdc95a44c3538fc2531ca8..39608752d0bbf439cc2ac17befc86e27a1b3e31f 100644 (file)
--- a/tools/libxc/xc_dom_x86.c
+++ b/tools/libxc/xc_dom_x86.c
@@ -58,8 +58,8 @@
 #define SPECIALPAGE_IOREQ    5
 #define SPECIALPAGE_IDENT_PT 6
 #define SPECIALPAGE_CONSOLE  7
-#define NR_SPECIAL_PAGES     8
-#define special_pfn(x) (0xff000u - NR_SPECIAL_PAGES + (x))
+#define special_pfn(x) \
+    (X86_HVM_END_SPECIAL_REGION - X86_HVM_NR_SPECIAL_PAGES + (x))
 
 #define NR_IOREQ_SERVER_PAGES 8
 #define ioreq_server_pfn(x) (special_pfn(0) - NR_IOREQ_SERVER_PAGES + (x))
@@ -589,7 +589,7 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom)
     void *hvm_info_page;
     uint32_t *ident_pt, domid = dom->guest_domid;
     int rc;
-    xen_pfn_t special_array[NR_SPECIAL_PAGES];
+    xen_pfn_t special_array[X86_HVM_NR_SPECIAL_PAGES];
     xen_pfn_t ioreq_server_array[NR_IOREQ_SERVER_PAGES];
     xc_interface *xch = dom->xch;
 
@@ -604,18 +604,19 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom)
     }
 
     /* Allocate and clear special pages. */
-    for ( i = 0; i < NR_SPECIAL_PAGES; i++ )
+    for ( i = 0; i < X86_HVM_NR_SPECIAL_PAGES; i++ )
         special_array[i] = special_pfn(i);
 
-    rc = xc_domain_populate_physmap_exact(xch, domid, NR_SPECIAL_PAGES, 0, 0,
-                                          special_array);
+    rc = xc_domain_populate_physmap_exact(xch, domid, X86_HVM_NR_SPECIAL_PAGES,
+                                          0, 0, special_array);
     if ( rc != 0 )
     {
         DOMPRINTF("Could not allocate special pages.");
         goto error_out;
     }
 
-    if ( xc_clear_domain_pages(xch, domid, special_pfn(0), NR_SPECIAL_PAGES) )
+    if ( xc_clear_domain_pages(xch, domid, special_pfn(0),
+                               X86_HVM_NR_SPECIAL_PAGES) )
             goto error_out;
 
     xc_hvm_param_set(xch, domid, HVM_PARAM_STORE_PFN,

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index bd604ac8755f1dd3dd11daf39e0a4e07a4a2b665..9207621081d3d795a06dae4f6a1e4bd323316d4d 100644 (file)
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -1065,11 +1065,14 @@ int libxl_domain_unpause(libxl_ctx *ctx, uint32_t domid)
     }
 
     if (type == LIBXL_DOMAIN_TYPE_HVM) {
-        rc = libxl__domain_resume_device_model(gc, domid);
-        if (rc < 0) {
-            LOG(ERROR, "failed to unpause device model for domain %u:%d",
-                domid, rc);
-            goto out;
+        if (libxl__device_model_version_running(gc, domid) !=
+            LIBXL_DEVICE_MODEL_VERSION_NONE) {
+            rc = libxl__domain_resume_device_model(gc, domid);
+            if (rc < 0) {
+                LOG(ERROR, "failed to unpause device model for domain %u:%d",
+                    domid, rc);
+                goto out;
+            }
         }
     }
     ret = xc_domain_unpause(ctx->xch, domid);
@@ -1616,11 +1619,11 @@ void libxl__destroy_domid(libxl__egc *egc, libxl__destroy_domid_state *dis)
 
     switch (libxl__domain_type(gc, domid)) {
     case LIBXL_DOMAIN_TYPE_HVM:
-        if (!libxl_get_stubdom_id(CTX, domid))
-            dm_present = 1;
-        else
+        if (libxl_get_stubdom_id(CTX, domid)) {
             dm_present = 0;
-        break;
+            break;
+        }
+        /* fall through */
     case LIBXL_DOMAIN_TYPE_PV:
         pid = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("/local/domain/%d/image/device-model-pid", domid));
         dm_present = (pid != NULL);
@@ -3240,7 +3243,7 @@ out:
 /******************************************************************************/
 
 int libxl__device_nic_setdefault(libxl__gc *gc, libxl_device_nic *nic,
-                                 uint32_t domid)
+                                 uint32_t domid, libxl_domain_build_info *info)
 {
     int rc;
 
@@ -3277,8 +3280,23 @@ int libxl__device_nic_setdefault(libxl__gc *gc, libxl_device_nic *nic,
 
     switch (libxl__domain_type(gc, domid)) {
     case LIBXL_DOMAIN_TYPE_HVM:
-        if (!nic->nictype)
-            nic->nictype = LIBXL_NIC_TYPE_VIF_IOEMU;
+        if (!nic->nictype) {
+            if (info != NULL) {
+                /* Path taken at creation time. */
+                if (info->device_model_version ==
+                    LIBXL_DEVICE_MODEL_VERSION_NONE)
+                    nic->nictype = LIBXL_NIC_TYPE_VIF;
+                else
+                    nic->nictype = LIBXL_NIC_TYPE_VIF_IOEMU;
+            } else {
+                /* Path taken when hot-adding a nic. */
+                if (libxl__device_model_version_running(gc, domid) ==
+                    LIBXL_DEVICE_MODEL_VERSION_NONE)
+                    nic->nictype = LIBXL_NIC_TYPE_VIF;
+                else
+                    nic->nictype = LIBXL_NIC_TYPE_VIF_IOEMU;
+            }
+        }
         break;
     case LIBXL_DOMAIN_TYPE_PV:
         if (nic->nictype == LIBXL_NIC_TYPE_VIF_IOEMU) {
@@ -3327,7 +3345,7 @@ void libxl__device_nic_add(libxl__egc *egc, uint32_t domid,
     libxl_device_nic_init(&nic_saved);
     libxl_device_nic_copy(CTX, &nic_saved, nic);
 
-    rc = libxl__device_nic_setdefault(gc, nic, domid);
+    rc = libxl__device_nic_setdefault(gc, nic, domid, NULL);
     if (rc) goto out;
 
     front = flexarray_make(gc, 16, 1);

diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 981cb84dd73d3aba654c5106a5651bf8423c0253..05606a74f215793e3e859ab5180658d3d023a0a9 100644 (file)
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -859,6 +859,14 @@ void libxl_mac_copy(libxl_ctx *ctx, libxl_mac *dst, libxl_mac *src);
 */
 #define LIBXL_HAVE_GFX_PASSTHRU_KIND
 
+/*
+ * LIBXL_HAVE_DEVICE_MODEL_VERSION_NONE
+ *
+ * In the case that LIBXL_HAVE_DEVICE_MODEL_VERSION_NONE is set libxl
+ * allows the creation of HVM guests without a device model.
+ */
+#define LIBXL_HAVE_DEVICE_MODEL_VERSION_NONE 1
+
 typedef char **libxl_string_list;
 void libxl_string_list_dispose(libxl_string_list *sl);
 int libxl_string_list_length(const libxl_string_list *sl);

diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index a9cf16a633f19283201cb003c8120ced9eb5ed92..261816a0b0fb3fff844fd533976e6eba6bf8c08b 100644 (file)
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -119,6 +119,8 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
                 b_info->u.hvm.bios = LIBXL_BIOS_TYPE_ROMBIOS; break;
             case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
                 b_info->u.hvm.bios = LIBXL_BIOS_TYPE_SEABIOS; break;
+            case LIBXL_DEVICE_MODEL_VERSION_NONE:
+                break;
             default:return ERROR_INVAL;
             }
 
@@ -132,6 +134,8 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
             if (b_info->u.hvm.bios == LIBXL_BIOS_TYPE_ROMBIOS)
                 return ERROR_INVAL;
             break;
+        case LIBXL_DEVICE_MODEL_VERSION_NONE:
+            break;
         default:abort();
         }
 
@@ -236,6 +240,9 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
                 break;
             }
             break;
+        case LIBXL_DEVICE_MODEL_VERSION_NONE:
+            b_info->video_memkb = 0;
+            break;
         case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
         default:
             switch (b_info->u.hvm.vga.kind) {
@@ -920,7 +927,8 @@ static void initiate_domain_create(libxl__egc *egc,
          * called libxl_device_nic_add when domcreate_launch_dm gets called,
          * but qemu needs the nic information to be complete.
          */
-        ret = libxl__device_nic_setdefault(gc, &d_config->nics[i], domid);
+        ret = libxl__device_nic_setdefault(gc, &d_config->nics[i], domid,
+                                           &d_config->b_info);
         if (ret) {
             LOG(ERROR, "Unable to set nic defaults for nic %d", i);
             goto error_out;
@@ -1261,6 +1269,12 @@ static void domcreate_launch_dm(libxl__egc *egc, libxl__multidev *multidev,
         libxl__device_console_add(gc, domid, &console, state, &device);
         libxl__device_console_dispose(&console);
 
+        if (d_config->b_info.device_model_version ==
+            LIBXL_DEVICE_MODEL_VERSION_NONE) {
+            domcreate_devmodel_started(egc, &dcs->dmss.dm, 0);
+            return;
+        }
+
         libxl_device_vkb_init(&vkb);
         libxl__device_vkb_add(gc, domid, &vkb);
         libxl_device_vkb_dispose(&vkb);

diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index 2de02738e3cc7a5310ca469bd208e50eb6463794..0aaefd957242e426ea909c70077d095f4d6c9392 100644 (file)
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -1606,7 +1606,8 @@ static void spawn_stub_launch_dm(libxl__egc *egc,
          * called libxl_device_nic_add at this point, but qemu needs
          * the nic information to be complete.
          */
-        ret = libxl__device_nic_setdefault(gc, &dm_config->nics[i], dm_domid);
+        ret = libxl__device_nic_setdefault(gc, &dm_config->nics[i], dm_domid,
+                                           &dm_config->b_info);
         if (ret)
             goto out;
     }

diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index d17ea86ee05f705c30424f67daf28fc3c49de458..deb3ffa720e580eb320b2a3926063c96acda1acd 100644 (file)
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -787,21 +787,23 @@ static int hvm_build_set_params(xc_interface *handle, uint32_t domid,
     uint64_t str_mfn, cons_mfn;
     int i;
 
-    va_map = xc_map_foreign_range(handle, domid,
-                                  XC_PAGE_SIZE, PROT_READ | PROT_WRITE,
-                                  HVM_INFO_PFN);
-    if (va_map == NULL)
-        return ERROR_FAIL;
+    if (info->device_model_version != LIBXL_DEVICE_MODEL_VERSION_NONE) {
+        va_map = xc_map_foreign_range(handle, domid,
+                                      XC_PAGE_SIZE, PROT_READ | PROT_WRITE,
+                                      HVM_INFO_PFN);
+        if (va_map == NULL)
+            return ERROR_FAIL;
 
-    va_hvm = (struct hvm_info_table *)(va_map + HVM_INFO_OFFSET);
-    va_hvm->apic_mode = libxl_defbool_val(info->u.hvm.apic);
-    va_hvm->nr_vcpus = info->max_vcpus;
-    memset(va_hvm->vcpu_online, 0, sizeof(va_hvm->vcpu_online));
-    memcpy(va_hvm->vcpu_online, info->avail_vcpus.map, info->avail_vcpus.size);
-    for (i = 0, sum = 0; i < va_hvm->length; i++)
-        sum += ((uint8_t *) va_hvm)[i];
-    va_hvm->checksum -= sum;
-    munmap(va_map, XC_PAGE_SIZE);
+        va_hvm = (struct hvm_info_table *)(va_map + HVM_INFO_OFFSET);
+        va_hvm->apic_mode = libxl_defbool_val(info->u.hvm.apic);
+        va_hvm->nr_vcpus = info->max_vcpus;
+        memset(va_hvm->vcpu_online, 0, sizeof(va_hvm->vcpu_online));
+        memcpy(va_hvm->vcpu_online, info->avail_vcpus.map, info->avail_vcpus.size);
+        for (i = 0, sum = 0; i < va_hvm->length; i++)
+            sum += ((uint8_t *) va_hvm)[i];
+        va_hvm->checksum -= sum;
+        munmap(va_map, XC_PAGE_SIZE);
+    }
 
     xc_hvm_param_get(handle, domid, HVM_PARAM_STORE_PFN, &str_mfn);
     xc_hvm_param_get(handle, domid, HVM_PARAM_CONSOLE_PFN, &cons_mfn);
@@ -867,7 +869,7 @@ static int libxl__domain_firmware(libxl__gc *gc,
 {
     libxl_ctx *ctx = libxl__gc_owner(gc);
     const char *firmware;
-    int e, rc = ERROR_FAIL;
+    int e, rc;
     int datalen = 0;
     void *data;
 
@@ -882,18 +884,34 @@ static int libxl__domain_firmware(libxl__gc *gc,
         case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
             firmware = "hvmloader";
             break;
+        case LIBXL_DEVICE_MODEL_VERSION_NONE:
+            if (info->kernel == NULL) {
+                LOG(ERROR, "no device model requested without a kernel");
+                rc = ERROR_FAIL;
+                goto out;
+            }
+            break;
         default:
             LOG(ERROR, "invalid device model version %d",
                 info->device_model_version);
-            return ERROR_FAIL;
-            break;
+            rc = ERROR_FAIL;
+            goto out;
         }
     }
 
-    rc = xc_dom_kernel_file(dom, libxl__abs_path(gc, firmware,
+    if (info->kernel != NULL &&
+        info->device_model_version == LIBXL_DEVICE_MODEL_VERSION_NONE) {
+        /* Try to load a kernel instead of the firmware. */
+        rc = xc_dom_kernel_file(dom, info->kernel);
+        if (rc == 0 && info->ramdisk != NULL)
+            rc = xc_dom_ramdisk_file(dom, info->ramdisk);
+    } else {
+        rc = xc_dom_kernel_file(dom, libxl__abs_path(gc, firmware,
                                                  libxl__xenfirmwaredir_path()));
+    }
+
     if (rc != 0) {
-        LOGE(ERROR, "xc_dom_kernel_file failed");
+        LOGE(ERROR, "xc_dom_{kernel_file/ramdisk_file} failed");
         goto out;
     }
 
@@ -904,6 +922,7 @@ static int libxl__domain_firmware(libxl__gc *gc,
         if (e) {
             LOGEV(ERROR, e, "failed to read SMBIOS firmware file %s",
                 info->u.hvm.smbios_firmware);
+            rc = ERROR_FAIL;
             goto out;
         }
         libxl__ptr_add(gc, data);
@@ -921,6 +940,7 @@ static int libxl__domain_firmware(libxl__gc *gc,
         if (e) {
             LOGEV(ERROR, e, "failed to read ACPI firmware file %s",
                 info->u.hvm.acpi_firmware);
+            rc = ERROR_FAIL;
             goto out;
         }
         libxl__ptr_add(gc, data);
@@ -933,6 +953,7 @@ static int libxl__domain_firmware(libxl__gc *gc,
 
     return 0;
 out:
+    assert(rc != 0);
     return rc;
 }
 
@@ -945,10 +966,13 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
     uint64_t mmio_start, lowmem_end, highmem_end, mem_size;
     libxl_domain_build_info *const info = &d_config->b_info;
     struct xc_dom_image *dom = NULL;
+    bool device_model =
+        info->device_model_version != LIBXL_DEVICE_MODEL_VERSION_NONE ?
+        true : false;
 
     xc_dom_loginit(ctx->xch);
 
-    dom = xc_dom_allocate(ctx->xch, NULL, NULL);
+    dom = xc_dom_allocate(ctx->xch, info->cmdline, NULL);
     if (!dom) {
         LOGE(ERROR, "xc_dom_allocate failed");
         rc = ERROR_NOMEM;
@@ -981,8 +1005,12 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
 
     if (dom->target_pages == 0)
         dom->target_pages = mem_size >> XC_PAGE_SHIFT;
-    if (dom->mmio_size == 0)
+    if (dom->mmio_size == 0 && device_model)
         dom->mmio_size = HVM_BELOW_4G_MMIO_LENGTH;
+    else if (dom->mmio_size == 0 && !device_model)
+        dom->mmio_size = GB(4) -
+                    ((X86_HVM_END_SPECIAL_REGION - X86_HVM_NR_SPECIAL_PAGES)
+                    << XC_PAGE_SHIFT);
     lowmem_end = mem_size;
     highmem_end = 0;
     mmio_start = (1ull << 32) - dom->mmio_size;
@@ -994,8 +1022,8 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
     dom->lowmem_end = lowmem_end;
     dom->highmem_end = highmem_end;
     dom->mmio_start = mmio_start;
-    dom->vga_hole_size = LIBXL_VGA_HOLE_SIZE;
-    dom->device_model = true;
+    dom->vga_hole_size = device_model ? LIBXL_VGA_HOLE_SIZE : 0;
+    dom->device_model = device_model;
 
     rc = libxl__domain_device_construct_rdm(gc, d_config,
                                             info->u.hvm.rdm_mem_boundary_memkb*1024,

diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 96842d3f4244a96d538a7620188cf0c94b4a6c76..15731a84a34f50e0595f6f6db220decc55b9b2dc 100644 (file)
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -115,6 +115,12 @@
 #define DOMID_XS_PATH "domid"
 #define INVALID_DOMID ~0
 
+/* Size macros. */
+#define __AC(X,Y)   (X##Y)
+#define _AC(X,Y)    __AC(X,Y)
+#define MB(_mb)     (_AC(_mb, ULL) << 20)
+#define GB(_gb)     (_AC(_gb, ULL) << 30)
+
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
 
 #define ROUNDUP(_val, _order)                                           \
@@ -1190,7 +1196,8 @@ _hidden int libxl__domain_build_info_setdefault(libxl__gc *gc,
 _hidden int libxl__device_disk_setdefault(libxl__gc *gc,
                                           libxl_device_disk *disk);
 _hidden int libxl__device_nic_setdefault(libxl__gc *gc, libxl_device_nic *nic,
-                                         uint32_t domid);
+                                         uint32_t domid,
+                                         libxl_domain_build_info *info);
 _hidden int libxl__device_vtpm_setdefault(libxl__gc *gc, libxl_device_vtpm *vtpm);
 _hidden int libxl__device_vfb_setdefault(libxl__gc *gc, libxl_device_vfb *vfb);
 _hidden int libxl__device_vkb_setdefault(libxl__gc *gc, libxl_device_vkb *vkb);

diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index cf3730fa74d027a547ad4b88f31277fd6c7c4e5a..9658356b0da61707282405db1feac2959c6a3c09 100644 (file)
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -98,6 +98,7 @@ libxl_device_model_version = Enumeration("device_model_version", [
     (0, "UNKNOWN"),
     (1, "QEMU_XEN_TRADITIONAL"), # Historical qemu-xen device model (qemu-dm)
     (2, "QEMU_XEN"),             # Upstream based qemu-xen device model
+    (3, "NONE"),                 # No device model
     ])
 
 libxl_console_type = Enumeration("console_type", [

diff --git a/tools/libxl/libxl_x86.c b/tools/libxl/libxl_x86.c
index 183b6c20e82b93da2caac680ad4cd5bb406b578e..46cfafb51305625a94bec73840634079433ee84c 100644 (file)
--- a/tools/libxl/libxl_x86.c
+++ b/tools/libxl/libxl_x86.c
@@ -7,10 +7,16 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
                                       libxl_domain_config *d_config,
                                       xc_domain_configuration_t *xc_config)
 {
-    if (d_config->c_info.type == LIBXL_DOMAIN_TYPE_HVM)
+
+    if (d_config->c_info.type == LIBXL_DOMAIN_TYPE_HVM &&
+        d_config->b_info.device_model_version !=
+        LIBXL_DEVICE_MODEL_VERSION_NONE) {
+        /* HVM domains with a device model. */
         xc_config->emulation_flags = XEN_X86_EMU_ALL;
-    else
+    } else {
+        /* PV or HVM domains without a device model. */
         xc_config->emulation_flags = 0;
+    }
 
     return 0;
 }
@@ -485,6 +491,7 @@ int libxl__arch_domain_construct_memmap(libxl__gc *gc,
     struct e820entry *e820 = NULL;
     uint64_t highmem_size =
                     dom->highmem_end ? dom->highmem_end - (1ull << 32) : 0;
+    uint32_t lowmem_start = dom->device_model ? GUEST_LOW_MEM_START_DEFAULT : 0;
 
     /* Add all rdm entries. */
     for (i = 0; i < d_config->num_rdms; i++)
@@ -505,8 +512,8 @@ int libxl__arch_domain_construct_memmap(libxl__gc *gc,
     e820 = libxl__malloc(gc, sizeof(struct e820entry) * e820_entries);
 
     /* Low memory */
-    e820[nr].addr = GUEST_LOW_MEM_START_DEFAULT;
-    e820[nr].size = dom->lowmem_end - GUEST_LOW_MEM_START_DEFAULT;
+    e820[nr].addr = lowmem_start;
+    e820[nr].size = dom->lowmem_end - lowmem_start;
     e820[nr].type = E820_RAM;
     nr++;
 

diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 2b6371d119c7d1461f19552cde3bdcc56b8eb0be..f9933cb83db746255e45015e8720e585ea8b3fe3 100644 (file)
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -2186,6 +2186,8 @@ skip_vfb:
         } else if (!strcmp(buf, "qemu-xen")) {
             b_info->device_model_version
                 = LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN;
+        } else if (!strcmp(buf, "none")) {
+            b_info->device_model_version = LIBXL_DEVICE_MODEL_VERSION_NONE;
         } else {
             fprintf(stderr,
                     "Unknown device_model_version \"%s\" specified\n", buf);