[libvirt] [PATCH v2 3/3] qemu: add support for shared memory mapping

[Martin Kletzander]

Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
---

Notes:
    v2:
     - memShared -> memAccess

 src/qemu/qemu_command.c                            | 27 ++++++++++++++++++++++
 .../qemuxml2argv-hugepages-shared.args             | 16 +++++++++++++
 tests/qemuxml2argvtest.c                           |  5 ++++
 3 files changed, 48 insertions(+)
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-hugepages-shared.args

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index e5270bd..4b89809 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6545,6 +6545,7 @@ qemuBuildNumaArgStr(virQEMUDriverConfigPtr cfg,
     for (i = 0; i < def->cpu->ncells; i++) {
         int cellmem = VIR_DIV_UP(def->cpu->cells[i].mem, 1024);
         def->cpu->cells[i].mem = cellmem * 1024;
+        virTristateSwitch memAccess = def->cpu->cells[i].memAccess;

         VIR_FREE(cpumask);
         VIR_FREE(nodemask);
@@ -6623,7 +6624,26 @@ qemuBuildNumaArgStr(virQEMUDriverConfigPtr cfg,
                 virBufferAsprintf(&buf,
                                   "memory-backend-file,prealloc=yes,mem-path=%s",
                                   mem_path);
+
+                switch (memAccess) {
+                case VIR_MEM_ACCESS_SHARED:
+                    virBufferAddLit(&buf, ",share=on");
+                case VIR_MEM_ACCESS_PRIVATE:
+                    virBufferAddLit(&buf, ",share=off");
+                    break;
+
+                case VIR_MEM_ACCESS_DEFAULT:
+                case VIR_MEM_ACCESS_LAST:
+                    break;
+                }
+
             } else {
+                if (memAccess) {
+                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                                   _("Shared memory mapping is supported "
+                                     "only with hugepages"));
+                    goto cleanup;
+                }
                 virBufferAddLit(&buf, "memory-backend-ram");
             }

@@ -6654,6 +6674,13 @@ qemuBuildNumaArgStr(virQEMUDriverConfigPtr cfg,

             virCommandAddArg(cmd, "-object");
             virCommandAddArgBuffer(cmd, &buf);
+        } else {
+            if (memAccess) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("Shared memory mapping is not supported "
+                                 "with this QEMU"));
+                goto cleanup;
+            }
         }

         virCommandAddArg(cmd, "-numa");
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hugepages-shared.args b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-shared.args
new file mode 100644
index 0000000..a7c7d92
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-shared.args
@@ -0,0 +1,16 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
+/usr/bin/qemu -S -M pc -m 4096 -smp 4 \
+-object memory-backend-file,prealloc=yes,mem-path=/dev/hugepages1G/libvirt/qemu,\
+size=1024M,id=ram-node0,host-nodes=0-3,policy=bind \
+-numa node,nodeid=0,cpus=0,memdev=ram-node0 \
+-object memory-backend-file,prealloc=yes,mem-path=/dev/hugepages2M/libvirt/qemu,\
+share=on,size=1024M,id=ram-node1,host-nodes=0-3,policy=bind \
+-numa node,nodeid=1,cpus=1,memdev=ram-node1 \
+-object memory-backend-file,prealloc=yes,mem-path=/dev/hugepages1G/libvirt/qemu,\
+share=off,size=1024M,id=ram-node2,host-nodes=0-3,policy=bind \
+-numa node,nodeid=2,cpus=2,memdev=ram-node2 \
+-object memory-backend-file,prealloc=yes,mem-path=/dev/hugepages1G/libvirt/qemu,\
+size=1024M,id=ram-node3,host-nodes=3,policy=bind \
+-numa node,nodeid=3,cpus=3,memdev=ram-node3 \
+-nographic -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -usb \
+-hda /dev/HostVG/QEMUGuest1 -net none -serial none -parallel none
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 5c28253..515058e 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -684,6 +684,8 @@ mymain(void)
             QEMU_CAPS_OBJECT_MEMORY_FILE);
     DO_TEST("hugepages-pages3", QEMU_CAPS_MEM_PATH, QEMU_CAPS_OBJECT_MEMORY_RAM,
             QEMU_CAPS_OBJECT_MEMORY_FILE);
+    DO_TEST("hugepages-shared", QEMU_CAPS_MEM_PATH, QEMU_CAPS_OBJECT_MEMORY_RAM,
+            QEMU_CAPS_OBJECT_MEMORY_FILE);
     DO_TEST("nosharepages", QEMU_CAPS_MACHINE_OPT, QEMU_CAPS_MEM_MERGE);
     DO_TEST("disk-cdrom", NONE);
     DO_TEST("disk-cdrom-network-http", QEMU_CAPS_KVM, QEMU_CAPS_DEVICE,
@@ -1207,6 +1209,9 @@ mymain(void)
     DO_TEST_PARSE_ERROR("cpu-numa3", NONE);
     DO_TEST_FAILURE("cpu-numa-disjoint", NONE);
     DO_TEST("cpu-numa-disjoint", QEMU_CAPS_NUMA);
+    DO_TEST_FAILURE("cpu-numa-memshared", QEMU_CAPS_SMP_TOPOLOGY,
+                    QEMU_CAPS_OBJECT_MEMORY_RAM);
+    DO_TEST_FAILURE("cpu-numa-memshared", QEMU_CAPS_SMP_TOPOLOGY);
     DO_TEST("cpu-host-model", NONE);
     skipLegacyCPUs = true;
     DO_TEST("cpu-host-model-fallback", NONE);
-- 
2.1.0