From 766ccea976922a5da2f76e26fc37e03ac14ecacd Mon Sep 17 00:00:00 2001

Message-Id: <766ccea976922a5da2f76e26fc37e03ac14ecacd@dist-git>

From: Michal Privoznik <mprivozn@redhat.com>

Date: Wed, 14 Jun 2017 16:58:12 +0200

Subject: [PATCH] qemu: Prefer hugepages over mem source='file'

https://bugzilla.redhat.com/show_bug.cgi?id=1214369

Consider the following XML:

  <memoryBacking>

    <hugepages>

      <page size='2048' unit='KiB' nodeset='1'/>

    </hugepages>

    <source type='file'/>

    <access mode='shared'/>

  </memoryBacking>

  <numa>

    <cell id='0' cpus='0-3' memory='512000' unit='KiB'/>

    <cell id='1' cpus='4-7' memory='512000' unit='KiB'/>

  </numa>

The following cmd line is generated:

  -object

  memory-backend-file,id=ram-node0,mem-path=/var/lib/libvirt/qemu/ram,

  share=yes,size=524288000 -numa node,nodeid=0,cpus=0-3,memdev=ram-node0

  -object

  memory-backend-file,id=ram-node1,mem-path=/var/lib/libvirt/qemu/ram,

  share=yes,size=524288000 -numa node,nodeid=1,cpus=4-7,memdev=ram-node1

This is obviously wrong as for node 1 hugepages should have been

used. The hugepages configuration is more specific than 

type='file'/>.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

(cherry picked from commit 992bf863fccfe1fa1d0c5a5277b9cee50abc48ef)

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

---

 src/qemu/qemu_command.c                            |  6 +--

 .../qemuxml2argv-hugepages-memaccess2.args         | 39 ++++++++++++++

 .../qemuxml2argv-hugepages-memaccess2.xml          | 62 ++++++++++++++++++++++

 tests/qemuxml2argvtest.c                           |  3 ++

 .../qemuxml2xmlout-hugepages-memaccess2.xml        |  1 +

 tests/qemuxml2xmltest.c                            |  1 +

 6 files changed, 109 insertions(+), 3 deletions(-)

 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.args

 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.xml

 create mode 120000 tests/qemuxml2xmloutdata/qemuxml2xmlout-hugepages-memaccess2.xml

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c

index c791214528..5013d3149d 100644

--- a/src/qemu/qemu_command.c

+++ b/src/qemu/qemu_command.c

@@ -3413,9 +3413,9 @@ qemuBuildMemoryBackendStr(virJSONValuePtr *backendProps,

             if (VIR_STRDUP(memPath, mem->nvdimmPath) < 0)

                 goto cleanup;

             prealloc = true;

-        } else if (def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE) {

-            /* We can have both pagesize and mem source,

-             * then check mem source first. */

+        } else if (!pagesize && def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE) {

+            /* We can have both pagesize and mem source. If that's the case,

+             * prefer hugepages as those are more specific. */

             if (VIR_STRDUP(memPath, cfg->memoryBackingDir) < 0)

                 goto cleanup;

         } else {

diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.args b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.args

new file mode 100644

index 0000000000..11985232a7

--- /dev/null

+++ b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.args

@@ -0,0 +1,39 @@

+LC_ALL=C \

+PATH=/bin \

+HOME=/home/test \

+USER=test \

+LOGNAME=test \

+QEMU_AUDIO_DRV=none \

+/usr/bin/qemu-system-i686 \

+-name QEMUGuest1 \

+-S \

+-M pc \

+-m size=4194304k,slots=16,maxmem=8388608k \

+-smp 4,sockets=4,cores=1,threads=1 \

+-object memory-backend-file,id=ram-node0,mem-path=/var/lib/libvirt/qemu/ram,\

+share=no,size=1073741824,host-nodes=0-3,policy=bind \

+-numa node,nodeid=0,cpus=0,memdev=ram-node0 \

+-object memory-backend-file,id=ram-node1,prealloc=yes,\

+mem-path=/dev/hugepages2M/libvirt/qemu/-1-QEMUGuest1,share=yes,size=1073741824,\

+host-nodes=0-3,policy=bind \

+-numa node,nodeid=1,cpus=1,memdev=ram-node1 \

+-object memory-backend-file,id=ram-node2,mem-path=/var/lib/libvirt/qemu/ram,\

+share=no,size=1073741824,host-nodes=0-3,policy=bind \

+-numa node,nodeid=2,cpus=2,memdev=ram-node2 \

+-object memory-backend-file,id=ram-node3,mem-path=/var/lib/libvirt/qemu/ram,\

+share=no,size=1073741824,host-nodes=3,policy=bind \

+-numa node,nodeid=3,cpus=3,memdev=ram-node3 \

+-object memory-backend-file,id=memdimm0,prealloc=yes,\

+mem-path=/dev/hugepages2M/libvirt/qemu/-1-QEMUGuest1,share=yes,size=536870912,\

+host-nodes=0-3,policy=bind \

+-device pc-dimm,node=1,memdev=memdimm0,id=dimm0,slot=0,addr=4294967296 \

+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \

+-nographic \

+-nodefaults \

+-monitor unix:/tmp/lib/domain--1-QEMUGuest1/monitor.sock,server,nowait \

+-no-acpi \

+-boot c \

+-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

diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.xml b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.xml

new file mode 100644

index 0000000000..c0011285c2

--- /dev/null

+++ b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.xml

@@ -0,0 +1,62 @@

+<domain type='qemu'>

+  <name>QEMUGuest1</name>

+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>

+  <maxMemory slots='16' unit='KiB'>8388608</maxMemory>

+  <memory unit='KiB'>4194304</memory>

+  <currentMemory unit='KiB'>4194304</currentMemory>

+  <memoryBacking>

+    <hugepages>

+      <page size='2048' unit='KiB' nodeset='1'/>

+    </hugepages>

+    <source type='file'/>

+    <access mode='private'/>

+  </memoryBacking>

+  <vcpu placement='static'>4</vcpu>

+  <numatune>

+    <memory mode='strict' nodeset='0-3'/>

+    <memnode cellid='3' mode='strict' nodeset='3'/>

+  </numatune>

+  <os>

+    <type arch='i686' machine='pc'>hvm</type>

+    <boot dev='hd'/>

+  </os>

+  <cpu>

+    <numa>

+      <cell id='0' cpus='0' memory='1048576' unit='KiB'/>

+      <cell id='1' cpus='1' memory='1048576' unit='KiB' memAccess='shared'/>

+      <cell id='2' cpus='2' memory='1048576' unit='KiB' memAccess='private'/>

+      <cell id='3' cpus='3' memory='1048576' unit='KiB'/>

+    </numa>

+  </cpu>

+  <clock offset='utc'/>

+  <on_poweroff>destroy</on_poweroff>

+  <on_reboot>restart</on_reboot>

+  <on_crash>destroy</on_crash>

+  <devices>

+    <emulator>/usr/bin/qemu-system-i686</emulator>

+    <disk type='block' device='disk'>

+      <source dev='/dev/HostVG/QEMUGuest1'/>

+      <target dev='hda' bus='ide'/>

+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>

+    </disk>

+    <controller type='usb' index='0'>

+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>

+    </controller>

+    <controller type='ide' index='0'>

+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>

+    </controller>

+    <controller type='pci' index='0' model='pci-root'/>

+    <input type='mouse' bus='ps2'/>

+    <input type='keyboard' bus='ps2'/>

+    <memballoon model='virtio'>

+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>

+    </memballoon>

+    <memory model='dimm'>

+      <target>

+        <size unit='KiB'>524288</size>

+        <node>1</node>

+      </target>

+      <address type='dimm' slot='0' base='0x100000000'/>

+    </memory>

+  </devices>

+</domain>

diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c

index 77e52bd33b..98e70033ec 100644

--- a/tests/qemuxml2argvtest.c

+++ b/tests/qemuxml2argvtest.c

@@ -830,6 +830,9 @@ mymain(void)

     DO_TEST("hugepages-memaccess", QEMU_CAPS_OBJECT_MEMORY_FILE,

             QEMU_CAPS_OBJECT_MEMORY_RAM, QEMU_CAPS_DEVICE_PC_DIMM,

             QEMU_CAPS_NUMA);

+    DO_TEST("hugepages-memaccess2", QEMU_CAPS_OBJECT_MEMORY_FILE,

+            QEMU_CAPS_OBJECT_MEMORY_RAM, QEMU_CAPS_DEVICE_PC_DIMM,

+            QEMU_CAPS_NUMA);

     DO_TEST("nosharepages", QEMU_CAPS_MACHINE_OPT, QEMU_CAPS_MEM_MERGE);

     DO_TEST("disk-cdrom", NONE);

     DO_TEST("disk-iscsi", NONE);

diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-hugepages-memaccess2.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-hugepages-memaccess2.xml

new file mode 120000

index 0000000000..3f7a38333f

--- /dev/null

+++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-hugepages-memaccess2.xml

@@ -0,0 +1 @@

+../qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.xml

\ No newline at end of file

diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c

index 511d1b3fb9..f2abad00cf 100644

--- a/tests/qemuxml2xmltest.c

+++ b/tests/qemuxml2xmltest.c

@@ -421,6 +421,7 @@ mymain(void)

     DO_TEST("hugepages-pages3", NONE);

     DO_TEST("hugepages-shared", NONE);

     DO_TEST("hugepages-memaccess", NONE);

+    DO_TEST("hugepages-memaccess2", NONE);

     DO_TEST("nosharepages", NONE);

     DO_TEST("restore-v2", NONE);

     DO_TEST("migrate", NONE);

-- 

2.13.1