[libvirt] [PATCH] libxl: add memory attach support

[Bob Liu]

Support for VIR_DOMAIN_DEVICE_MEMORY on domainAttachDeviceFlags API in libxl
driver, using libxl_set_memory_target in xen libxl.

With "virsh attach-device" command we can then hotplug memory to a domain:
<memory model='dimm'>
    <target>
        <size unit='MiB'>128</size>
        <node>0</node>
    </target>
</memory>

$ virsh attach-device domain_name this.xml --live

Signed-off-by: Bob Liu <bob.liu at oracle.com>
---
 src/libxl/libxl_domain.c |  1 +
 src/libxl/libxl_driver.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c
index f529a2e..3924ba0 100644
--- a/src/libxl/libxl_domain.c
+++ b/src/libxl/libxl_domain.c
@@ -414,6 +414,7 @@ virDomainDefParserConfig libxlDomainDefParserConfig = {
     .macPrefix = { 0x00, 0x16, 0x3e },
     .devicesPostParseCallback = libxlDomainDeviceDefPostParse,
     .domainPostParseCallback = libxlDomainDefPostParse,
+    .features = VIR_DOMAIN_DEF_FEATURE_MEMORY_HOTPLUG
 };
 
 
diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
index a34eb02..541ea3b 100644
--- a/src/libxl/libxl_driver.c
+++ b/src/libxl/libxl_driver.c
@@ -3085,6 +3085,30 @@ libxlDomainAttachHostUSBDevice(libxlDriverPrivatePtr driver,
 #endif
 
 static int
+libxlDomainAttachMemory(libxlDriverPrivatePtr driver,
+                        virDomainObjPtr vm,
+                        virDomainMemoryDefPtr mem)
+{
+    int res = 0;
+    libxlDriverConfigPtr cfg = libxlDriverConfigGet(driver);
+
+    if (mem->targetNode != 0) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("unsupport non-zero target node for memory device"));
+        return -1;
+    }
+
+    res = libxl_set_memory_target(cfg->ctx, vm->def->id, mem->size, 1, 1);
+    if (res < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Failed to attach %lluKB memory for domain %d"),
+                       mem->size, vm->def->id);
+        return -1;
+    }
+    return 0;
+}
+
+static int
 libxlDomainAttachHostDevice(libxlDriverPrivatePtr driver,
                             virDomainObjPtr vm,
                             virDomainHostdevDefPtr hostdev)
@@ -3284,6 +3308,11 @@ libxlDomainAttachDeviceLive(libxlDriverPrivatePtr driver,
                 dev->data.hostdev = NULL;
             break;
 
+        case VIR_DOMAIN_DEVICE_MEMORY:
+            ret = libxlDomainAttachMemory(driver, vm, dev->data.memory);
+            dev->data.memory = NULL;
+            break;
+
         default:
             virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                            _("device type '%s' cannot be attached"),
-- 
2.6.5