[libvirt] [PATCH v2 2/2] qemu: Implement support for locking domain's memory pages

Laine Stump laine at laine.org
Fri May 17 00:21:52 UTC 2013


On 05/16/2013 05:23 PM, Jiri Denemark wrote:
> ---
>  src/qemu/qemu_capabilities.c                           |  2 ++
>  src/qemu/qemu_capabilities.h                           |  1 +
>  src/qemu/qemu_command.c                                | 11 +++++++++++
>  tests/qemuxml2argvdata/qemuxml2argv-mlock-off.args     |  4 ++++
>  tests/qemuxml2argvdata/qemuxml2argv-mlock-off.xml      | 15 +++++++++++++++
>  tests/qemuxml2argvdata/qemuxml2argv-mlock-on.args      |  4 ++++
>  tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml       | 18 ++++++++++++++++++
>  .../qemuxml2argv-mlock-unsupported.args                |  4 ++++
>  .../qemuxml2argv-mlock-unsupported.xml                 | 15 +++++++++++++++
>  tests/qemuxml2argvtest.c                               |  5 +++++
>  10 files changed, 79 insertions(+)
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-mlock-off.args
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-mlock-off.xml
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-mlock-on.args
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-mlock-unsupported.args
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-mlock-unsupported.xml
>
> diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
> index 488cbfe..82129a2 100644
> --- a/src/qemu/qemu_capabilities.c
> +++ b/src/qemu/qemu_capabilities.c
> @@ -230,6 +230,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
>                "mem-merge",
>                "vnc-websocket",
>                "drive-discard",
> +              "mlock",
>      );
>  
>  struct _virQEMUCaps {
> @@ -2246,6 +2247,7 @@ struct virQEMUCapsCommandLineProps {
>  static struct virQEMUCapsCommandLineProps virQEMUCapsCommandLine[] = {
>      { "machine", "mem-merge", QEMU_CAPS_MEM_MERGE },
>      { "drive", "discard", QEMU_CAPS_DRIVE_DISCARD },
> +    { "realtime", "mlock", QEMU_CAPS_MLOCK },
>  };
>  
>  static int
> diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
> index 173ca77..117bf8a 100644
> --- a/src/qemu/qemu_capabilities.h
> +++ b/src/qemu/qemu_capabilities.h
> @@ -187,6 +187,7 @@ enum virQEMUCapsFlags {
>      QEMU_CAPS_MEM_MERGE          = 146, /* -machine mem-merge */
>      QEMU_CAPS_VNC_WEBSOCKET      = 147, /* -vnc x:y,websocket */
>      QEMU_CAPS_DRIVE_DISCARD      = 148, /* -drive discard=off(ignore)|on(unmap) */
> +    QEMU_CAPS_MLOCK              = 149, /* -realtime mlock=on|off */
>  
>      QEMU_CAPS_LAST,                   /* this must always be the last item */
>  };
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index 5b95c07..c268a3a 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -6541,6 +6541,17 @@ qemuBuildCommandLine(virConnectPtr conn,
>                               cfg->hugepagePath, NULL);
>      }
>  
> +    if (def->mem.locked && !virQEMUCapsGet(qemuCaps, QEMU_CAPS_MLOCK)) {
> +        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                       _("memory locking not supported by QEMU binary"));
> +        goto error;
> +    }
> +    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_MLOCK)) {
> +        virCommandAddArg(cmd, "-realtime");
> +        virCommandAddArgFormat(cmd, "mlock=%s",
> +                               def->mem.locked ? "on" : "off");
> +    }
> +

If this is going to lock all of the guests memory in RAM, doesn't
libvirt need to increase RLIMIT_MEMLOCK for the qemu process? (I
recently added virCommandSetMaxMemLock(), which will do that if you need
it).


>      virCommandAddArg(cmd, "-smp");
>      if (!(smp = qemuBuildSmpArgStr(def, qemuCaps)))
>          goto error;
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-mlock-off.args b/tests/qemuxml2argvdata/qemuxml2argv-mlock-off.args
> new file mode 100644
> index 0000000..2a5d94c
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-mlock-off.args
> @@ -0,0 +1,4 @@
> +LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test \
> +/usr/bin/qemu -S -M pc -m 214 -realtime mlock=off \
> +-smp 1 -nographic -monitor unix:/tmp/test-monitor,server,nowait \
> +-no-acpi -boot c -usb -net none -serial none -parallel none
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-mlock-off.xml b/tests/qemuxml2argvdata/qemuxml2argv-mlock-off.xml
> new file mode 100644
> index 0000000..4125ca5
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-mlock-off.xml
> @@ -0,0 +1,15 @@
> +<domain type='qemu'>
> +  <name>QEMUGuest1</name>
> +  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
> +  <memory unit='KiB'>219136</memory>
> +  <currentMemory unit='KiB'>219136</currentMemory>
> +  <vcpu placement='static'>1</vcpu>
> +  <os>
> +    <type arch='i686' machine='pc'>hvm</type>
> +    <boot dev='hd'/>
> +  </os>
> +  <devices>
> +    <emulator>/usr/bin/qemu</emulator>
> +    <memballoon model='none'/>
> +  </devices>
> +</domain>
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.args b/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.args
> new file mode 100644
> index 0000000..bb6de13
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.args
> @@ -0,0 +1,4 @@
> +LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test \
> +/usr/bin/qemu -S -M pc -m 214 -realtime mlock=on \
> +-smp 1 -nographic -monitor unix:/tmp/test-monitor,server,nowait \
> +-no-acpi -boot c -usb -net none -serial none -parallel none
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml b/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml
> new file mode 100644
> index 0000000..20a5eaa
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-mlock-on.xml
> @@ -0,0 +1,18 @@
> +<domain type='qemu'>
> +  <name>QEMUGuest1</name>
> +  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
> +  <memory unit='KiB'>219136</memory>
> +  <currentMemory unit='KiB'>219136</currentMemory>
> +  <memoryBacking>
> +    <locked/>
> +  </memoryBacking>
> +  <vcpu placement='static'>1</vcpu>
> +  <os>
> +    <type arch='i686' machine='pc'>hvm</type>
> +    <boot dev='hd'/>
> +  </os>
> +  <devices>
> +    <emulator>/usr/bin/qemu</emulator>
> +    <memballoon model='none'/>
> +  </devices>
> +</domain>
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-mlock-unsupported.args b/tests/qemuxml2argvdata/qemuxml2argv-mlock-unsupported.args
> new file mode 100644
> index 0000000..54dd3b9
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-mlock-unsupported.args
> @@ -0,0 +1,4 @@
> +LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test \
> +/usr/bin/qemu -S -M pc -m 214 \
> +-smp 1 -nographic -monitor unix:/tmp/test-monitor,server,nowait \
> +-no-acpi -boot c -usb -net none -serial none -parallel none
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-mlock-unsupported.xml b/tests/qemuxml2argvdata/qemuxml2argv-mlock-unsupported.xml
> new file mode 100644
> index 0000000..4125ca5
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-mlock-unsupported.xml
> @@ -0,0 +1,15 @@
> +<domain type='qemu'>
> +  <name>QEMUGuest1</name>
> +  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
> +  <memory unit='KiB'>219136</memory>
> +  <currentMemory unit='KiB'>219136</currentMemory>
> +  <vcpu placement='static'>1</vcpu>
> +  <os>
> +    <type arch='i686' machine='pc'>hvm</type>
> +    <boot dev='hd'/>
> +  </os>
> +  <devices>
> +    <emulator>/usr/bin/qemu</emulator>
> +    <memballoon model='none'/>
> +  </devices>
> +</domain>
> diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
> index c751440..d853308 100644
> --- a/tests/qemuxml2argvtest.c
> +++ b/tests/qemuxml2argvtest.c
> @@ -1007,6 +1007,11 @@ mymain(void)
>              QEMU_CAPS_DEVICE_SCSI_GENERIC,
>              QEMU_CAPS_DEVICE_SCSI_GENERIC_BOOTINDEX);
>  
> +    DO_TEST("mlock-on", QEMU_CAPS_MLOCK);
> +    DO_TEST_FAILURE("mlock-on", NONE);
> +    DO_TEST("mlock-off", QEMU_CAPS_MLOCK);
> +    DO_TEST("mlock-unsupported", NONE);
> +
>      virObjectUnref(driver.config);
>      virObjectUnref(driver.caps);
>      virObjectUnref(driver.xmlopt);




More information about the libvir-list mailing list