qemu: Build command line for virtio-mem

Nothing special is happening here. All important changes were
done when for 'virtio-pmem' (adjusting the code to put virtio
memory on PCI bus, generating alias using
qemuDomainDeviceAliasIndex(). The only bit that might look
suspicious is no prealloc for virtio-mem. But if you think about
it, the whole purpose of this device is to change amount of
memory exposed to guest on the fly. There is no point in locking
the whole backend in memory.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/src/qemu/qemu_alias.c b/src/qemu/qemu_alias.c
index 79e8953b2f5c2ab03f884953bcf4b1aeab67c353..81a1e7eeed2fec2ed9738212fd8682a9008f3651 100644 (file)
--- a/src/qemu/qemu_alias.c
+++ b/src/qemu/qemu_alias.c
@@ -475,8 +475,11 @@ qemuDeviceMemoryGetAliasID(virDomainDef *def,
     size_t i;
     int maxidx = 0;
 
-    /* virtio-pmem goes onto PCI bus and thus DIMM address is not valid */
-    if (!oldAlias && mem->model != VIR_DOMAIN_MEMORY_MODEL_VIRTIO_PMEM)
+    /* virtio-pmem and virtio-mem go onto PCI bus and thus DIMM address is not
+     * valid */
+    if (!oldAlias &&
+        mem->model != VIR_DOMAIN_MEMORY_MODEL_VIRTIO_PMEM &&
+        mem->model != VIR_DOMAIN_MEMORY_MODEL_VIRTIO_MEM)
         return mem->info.addr.dimm.slot;
 
     for (i = 0; i < def->nmems; i++) {
@@ -523,6 +526,8 @@ qemuAssignDeviceMemoryAlias(virDomainDef *def,
         prefix = "virtiopmem";
         break;
     case VIR_DOMAIN_MEMORY_MODEL_VIRTIO_MEM:
+        prefix = "virtiomem";
+        break;
     case VIR_DOMAIN_MEMORY_MODEL_NONE:
     case VIR_DOMAIN_MEMORY_MODEL_LAST:
     default:

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 0814e713f79324fbe069e48573f76218459d0b81..eaa1e0deb99de1ccd62d810fd5188d7a4d8f7484 100644 (file)
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -3028,9 +3028,23 @@ qemuBuildMemoryBackendProps(virJSONValue **backendProps,
         virJSONValueObjectAdd(props, "b:x-use-canonical-path-for-ramblock-id", false, NULL) < 0)
         return -1;
 
-    if (!priv->memPrealloc &&
-        virJSONValueObjectAdd(props, "B:prealloc", prealloc, NULL) < 0)
-        return -1;
+    if (mem->model == VIR_DOMAIN_MEMORY_MODEL_VIRTIO_MEM) {
+        /* Explicitly disable prealloc for virtio-mem as it's not supported
+         * currently. Warn users if their config would result in prealloc. */
+        if (priv->memPrealloc || prealloc) {
+            VIR_WARN("Memory preallocation is unsupported for virtio-mem memory devices");
+        }
+        if (priv->memPrealloc &&
+            virJSONValueObjectAppendBoolean(props, "prealloc", 0) < 0)
+            return -1;
+        if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MEMORY_BACKEND_RESERVE) &&
+            virJSONValueObjectAppendBoolean(props, "reserve", 0) < 0)
+            return -1;
+    } else {
+        if (!priv->memPrealloc &&
+            virJSONValueObjectAdd(props, "B:prealloc", prealloc, NULL) < 0)
+            return -1;
+    }
 
     if (virJSONValueObjectAdd(props, "U:size", mem->size * 1024, NULL) < 0)
         return -1;
@@ -3210,6 +3224,9 @@ qemuBuildMemoryDeviceStr(const virDomainDef *def,
         break;
 
     case VIR_DOMAIN_MEMORY_MODEL_VIRTIO_MEM:
+        device = "virtio-mem-pci";
+        break;
+
     case VIR_DOMAIN_MEMORY_MODEL_NONE:
     case VIR_DOMAIN_MEMORY_MODEL_LAST:
     default:
@@ -3226,6 +3243,11 @@ qemuBuildMemoryDeviceStr(const virDomainDef *def,
     if (mem->labelsize)
         virBufferAsprintf(&buf, "label-size=%llu,", mem->labelsize * 1024);
 
+    if (mem->blocksize) {
+        virBufferAsprintf(&buf, "block-size=%llu,", mem->blocksize * 1024);
+        virBufferAsprintf(&buf, "requested-size=%llu,", mem->requestedsize * 1024);
+    }
+
     if (mem->uuid) {
         char uuidstr[VIR_UUID_STRING_BUFLEN];
 

diff --git a/tests/qemuxml2argvdata/memory-hotplug-virtio-mem.x86_64-latest.args b/tests/qemuxml2argvdata/memory-hotplug-virtio-mem.x86_64-latest.args
new file mode 100644 (file)
index 0000000..22ee1bc
--- /dev/null
+++ b/tests/qemuxml2argvdata/memory-hotplug-virtio-mem.x86_64-latest.args
@@ -0,0 +1,41 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-i386 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/tmp/lib/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine pc,accel=kvm,usb=off,dump-guest-core=off \
+-cpu qemu64 \
+-m size=2095104k,slots=16,maxmem=1099511627776k \
+-overcommit mem-lock=off \
+-smp 2,sockets=2,dies=1,cores=1,threads=1 \
+-object '{"qom-type":"memory-backend-ram","id":"ram-node0","size":2145386496}' \
+-numa node,nodeid=0,cpus=0-1,memdev=ram-node0 \
+-object '{"qom-type":"memory-backend-ram","id":"memvirtiomem0","reserve":false,"size":1073741824}' \
+-device virtio-mem-pci,node=0,block-size=2097152,requested-size=536870912,memdev=memvirtiomem0,id=virtiomem0,bus=pci.0,addr=0x2 \
+-object '{"qom-type":"memory-backend-file","id":"memvirtiomem1","mem-path":"/dev/hugepages2M/libvirt/qemu/-1-QEMUGuest1","reserve":false,"size":2147483648,"host-nodes":[1,2,3],"policy":"bind"}' \
+-device virtio-mem-pci,node=0,block-size=2097152,requested-size=1073741824,memdev=memvirtiomem1,id=virtiomem1,bus=pci.0,addr=0x3 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-boot strict=on \
+-device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \
+-blockdev '{"driver":"host_device","filename":"/dev/HostVG/QEMUGuest1","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \
+-blockdev '{"node-name":"libvirt-1-format","read-only":false,"driver":"raw","file":"libvirt-1-storage"}' \
+-device ide-hd,bus=ide.0,unit=0,drive=libvirt-1-format,id=ide0-0-0,bootindex=1 \
+-audiodev id=audio1,driver=none \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4 \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on

diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 13e387df3f5233d6ad3a1969441595dc98fbd024..bf05c9c6c33e0f55d0b6820fd2bd35b1cd3cc5ab 100644 (file)
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -3085,6 +3085,7 @@ mymain(void)
                  ARG_END);
     DO_TEST_CAPS_VER("memory-hotplug-virtio-pmem", "5.2.0");
     DO_TEST_CAPS_LATEST("memory-hotplug-virtio-pmem");
+    DO_TEST_CAPS_LATEST("memory-hotplug-virtio-mem");
 
     DO_TEST("machine-aeskeywrap-on-caps",
             QEMU_CAPS_AES_KEY_WRAP,