7:25 a.m.
Add conversion from xml to argv for subelements
source,access and allocation of <memoryBacking>
This change introduces support for preallocated
shared file descriptor based memory backing.
It allows vhost-user to be used without hugepages.
Configured by these elements:
<memoryBacking>
<source type="file|anonymous"/>
<access Mode="shared|private"/>
<allocation mode="immediate|ondemand"/>
</memoryBacking>
---
src/qemu/qemu_command.c | 56 ++++++++++++++++++++++
src/qemu/qemu_command.h | 4 ++
.../qemuxml2argv-memorybacking-set.args | 6 ++-
tests/qemuxml2argvtest.c | 3 ++
4 files changed, 68 insertions(+), 1 deletion(-)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 6944129..321e71f 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -9328,6 +9328,9 @@ qemuBuildCommandLine(virQEMUDriverPtr driver,
if (qemuBuildNVRAMCommandLine(cmd, def, qemuCaps) < 0)
goto error;
+ if (qemuBuildMemoryBackendCommandLine(cmd, def, qemuCaps) < 0)
+ goto error;
+
if (snapshot)
virCommandAddArgList(cmd, "-loadvm", snapshot->def->name, NULL);
@@ -9592,3 +9595,56 @@ qemuBuildChrDeviceStr(char **deviceStr,
return ret;
}
+
+static char *
+qemuBuildMemoryBackendFileStr(const virDomainDef *def)
+{
+ virBuffer buf = VIR_BUFFER_INITIALIZER;
+ const char template[] =
"memory-backend-file,id=mem,size=1024M,mem-path=/var/lib/libvirt/qemu";
+
+ if (VIR_DOMAIN_MEMORY_ACCESS_SHARED == def->mem.access) {
+ // add ",share=on" to -object memory-backend-file
+ virBufferAsprintf(&buf, "%s,share=on", template);
+ } else {
+ virBufferAsprintf(&buf, "%s", template);
+ }
+
+
+ if (virBufferCheckError(&buf) < 0)
+ goto error;
+
+ return virBufferContentAndReset(&buf);
+
+ error:
+ virBufferFreeAndReset(&buf);
+ return NULL;
+}
+
+
+int
+qemuBuildMemoryBackendCommandLine(virCommandPtr cmd,
+ const virDomainDef *def,
+ virQEMUCapsPtr qemuCaps __attribute__((unused)))
+{
+ char *optstr = NULL;
+
+ if (VIR_DOMAIN_MEMORY_ALLOCATION_IMMEDIATE == def->mem.allocation) {
+ // add '-mem-prealloc'
+ virCommandAddArg(cmd, "-mem-prealloc");
+ }
+
+ if (VIR_DOMAIN_MEMORY_SOURCE_FILE == def->mem.source) {
+ optstr = qemuBuildMemoryBackendFileStr(def);
+ if (optstr) {
+ virCommandAddArg(cmd, "-object");
+ virCommandAddArg(cmd, optstr);
+ VIR_FREE(optstr);
+ }
+
+ // add '-object
memory-backend-file,id=mem,size=1024M,mem-path=/var/lib/libvirt/qemu'
+ // add '-numa node,memdev=mem'
+ virCommandAddArgList(cmd, "-numa", "node,memdev=mem", NULL);
+ }
+
+ return 0;
+}
diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h
index 9ff4edb..f95d0ea 100644
--- a/src/qemu/qemu_command.h
+++ b/src/qemu/qemu_command.h
@@ -175,5 +175,9 @@ bool qemuCheckCCWS390AddressSupport(const virDomainDef *def,
virDomainDeviceInfo info,
virQEMUCapsPtr qemuCaps,
const char *devicename);
+int
+qemuBuildMemoryBackendCommandLine(virCommandPtr cmd,
+ const virDomainDef *def,
+ virQEMUCapsPtr qemuCaps);
#endif /* __QEMU_COMMAND_H__*/
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-memorybacking-set.args
b/tests/qemuxml2argvdata/qemuxml2argv-memorybacking-set.args
index bb702dc..626fb21 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-memorybacking-set.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-memorybacking-set.args
@@ -19,4 +19,8 @@ QEMU_AUDIO_DRV=none \
-usb \
-drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-ide0-0-0 \
-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
--device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 \
+-mem-prealloc \
+-object memory-backend-file,id=mem,size=1024M,mem-path=/var/lib/libvirt/qemu,\
+share=on \
+-numa node,memdev=mem
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index a4b8bf4..401b455 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -2024,6 +2024,9 @@ mymain(void)
DO_TEST("acpi-table", NONE);
+ DO_TEST("memorybacking-unset", NONE);
+ DO_TEST("memorybacking-set", NONE);
+
qemuTestDriverFree(&driver);
return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
--
2.1.0
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