[PATCH v3 32/32] libxl: allow the creation of HVM domains without a device model.

[Roger Pau Monne <roger.pau@citrix.com>]

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 unconditinally set the nic type
to LIBXL_NIC_TYPE_VIF.

Signed-off-by: Roger Pau Monné <roger.pau@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>
---
 docs/man/xl.cfg.pod.5       |  5 ++++
 tools/libxl/libxl.c         |  7 +++---
 tools/libxl/libxl_create.c  | 18 ++++++++++++++
 tools/libxl/libxl_dom.c     | 60 ++++++++++++++++++++++++++++++---------------
 tools/libxl/libxl_types.idl |  1 +
 tools/libxl/libxl_x86.c     |  4 ++-
 tools/libxl/xl_cmdimpl.c    |  2 ++
 7 files changed, 72 insertions(+), 25 deletions(-)

diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
index a3e0e2e..1270605 100644
--- a/docs/man/xl.cfg.pod.5
+++ b/docs/man/xl.cfg.pod.5
@@ -1631,6 +1631,11 @@ 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
+in this mode.
+
 =back
 
 It is recommended to accept the default value for new guests.  If
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index e9a2d26..a6690cf 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -1590,11 +1590,10 @@ 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;
+        }
     case LIBXL_DOMAIN_TYPE_PV:
         pid = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "/local/domain/%d/image/device-model-pid", domid));
         dm_present = (pid != NULL);
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index f366a09..1444e40 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -164,6 +164,8 @@ 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;
             }
 
@@ -177,6 +179,8 @@ 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();
         }
 
@@ -278,6 +282,9 @@ 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) {
@@ -945,6 +952,11 @@ static void initiate_domain_create(libxl__egc *egc,
         ret = libxl__device_nic_setdefault(gc, &d_config->nics[i], domid);
         if (ret) goto error_out;
 
+        /* HVM guests without a device model only have PV nics. */
+        if (d_config->b_info.device_model_version ==
+            LIBXL_DEVICE_MODEL_VERSION_NONE)
+            d_config->nics[i].nictype = LIBXL_NIC_TYPE_VIF;
+
         if (d_config->nics[i].devid > last_devid)
             last_devid = d_config->nics[i].devid;
     }
@@ -1293,6 +1305,12 @@ 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_dom.c b/tools/libxl/libxl_dom.c
index 6ce4115..59854a1 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -789,21 +789,23 @@ 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 -1;
-
-    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);
+    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 -1;
+
+        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);
@@ -884,6 +886,12 @@ 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");
+                return ERROR_FAIL;
+            }
+            break;
         default:
             LOG(ERROR, "invalid device model version %d",
                 info->device_model_version);
@@ -892,10 +900,19 @@ static int libxl__domain_firmware(libxl__gc *gc,
         }
     }
 
-    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;
     }
 
@@ -946,10 +963,13 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
     int ret;
     uint64_t mmio_start, lowmem_end, highmem_end, mem_size;
     struct xc_dom_image *dom = NULL;
+    bool emulated_devices =
+        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");
         goto out;
@@ -979,7 +999,7 @@ 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 && emulated_devices)
         dom->mmio_size = HVM_BELOW_4G_MMIO_LENGTH;
     lowmem_end = mem_size;
     highmem_end = 0;
@@ -992,7 +1012,7 @@ 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->emulation = true;
+    dom->emulation = emulated_devices;
 
     if (info->num_vnuma_nodes != 0) {
         int i;
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index e1632fa..0283197 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -86,6 +86,7 @@ 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 f04433a..435290b 100644
--- a/tools/libxl/libxl_x86.c
+++ b/tools/libxl/libxl_x86.c
@@ -5,7 +5,9 @@ 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)
         xc_config->emulation_flags = (EMU_LAPIC | EMU_HPET | EMU_PMTIMER |
                                       EMU_RTC | EMU_IOAPIC | EMU_PIC |
                                       EMU_PMU | EMU_VGA | EMU_IOMMU);
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index c858068..3d9b3d4 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -2067,6 +2067,8 @@ 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);
-- 
1.9.5 (Apple Git-50.3)


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