Ping.
Can anyone else review this patch?
Regards,
Satoru
On 03/12/2013 05:40 AM, Paolo Bonzini wrote:
> Il 14/02/2013 21:21, Satoru Moriya ha scritto:
>> We have some plans to migrate legacy enterprise systems which require
>> low latency (10 msec order) to kvm virtualized environment. In our
>> usecase, the system runs with other untrusted guests and so locking
>> memory which is used by the system is needed to avoid latency impacts
>> from other guests' memory activity.
>>
>> ChangeLog:
>> v2
>> - Change the option name from -mlock to -realtime mlock=on|off
>> - Rebase qemu version 1.3.91
>> - Update patch description
>>
>> ---
>> In certain scenario, latency induced by paging is significant and
>> memory locking is needed. Also, in the scenario with untrusted
>> guests, latency improvement due to mlock is desired.
>>
>> This patch introduces a following new option to mlock guest and qemu
>> memory:
>>
>> -realtime mlock=on|off
>>
>> Signed-off-by: Satoru Moriya <satoru.mor...@hds.com>
>
> Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
>
> As a follow up it would be nice to move -mem-prealloc/-mem-path under
> -realtime as well.
>
> Paolo
>
>> ---
>> include/sysemu/os-posix.h | 1 +
>> include/sysemu/os-win32.h | 1 +
>> os-posix.c | 8 ++++++++
>> qemu-options.hx | 13 +++++++++++++
>> vl.c | 31 +++++++++++++++++++++++++++++++
>> 5 files changed, 54 insertions(+)
>>
>> diff --git a/include/sysemu/os-posix.h b/include/sysemu/os-posix.h
>> index 7f198e4..2f2ead6 100644
>> --- a/include/sysemu/os-posix.h
>> +++ b/include/sysemu/os-posix.h
>> @@ -31,6 +31,7 @@ void os_set_proc_name(const char *s); void
>> os_setup_signal_handling(void); void os_daemonize(void); void
>> os_setup_post(void);
>> +void os_mlock(void);
>>
>> typedef struct timeval qemu_timeval; #define qemu_gettimeofday(tp)
>> gettimeofday(tp, NULL) diff --git a/include/sysemu/os-win32.h
>> b/include/sysemu/os-win32.h index bf9edeb..a74ca13 100644
>> --- a/include/sysemu/os-win32.h
>> +++ b/include/sysemu/os-win32.h
>> @@ -80,6 +80,7 @@ static inline void os_daemonize(void) {} static
>> inline void os_setup_post(void) {} void os_set_line_buffering(void);
>> static inline void os_set_proc_name(const char *dummy) {}
>> +static inline void os_mlock(void) {}
>>
>> #if !defined(EPROTONOSUPPORT)
>> # define EPROTONOSUPPORT EINVAL
>> diff --git a/os-posix.c b/os-posix.c
>> index 5c64518..1304b0e 100644
>> --- a/os-posix.c
>> +++ b/os-posix.c
>> @@ -363,3 +363,11 @@ bool is_daemonized(void) {
>> return daemonize;
>> }
>> +
>> +void os_mlock(void)
>> +{
>> + if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
>> + perror("mlockall");
>> + exit(1);
>> + }
>> +}
>> diff --git a/qemu-options.hx b/qemu-options.hx index 9d7131a..843fcb4
>> 100644
>> --- a/qemu-options.hx
>> +++ b/qemu-options.hx
>> @@ -2464,6 +2464,19 @@ STEXI
>> Do not start CPU at startup (you must type 'c' in the monitor).
>> ETEXI
>>
>> +DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
>> + "-realtime [mlock=on|off]\n"
>> + " run qemu with realtime features\n"
>> + " mlock=on|off controls mlock support (default: on)\n",
>> + QEMU_ARCH_ALL)
>> +STEXI
>> +@item -realtime mlock=on|off
>> +@findex -realtime
>> +Run qemu with realtime features.
>> +mlocking qemu and guest memory can be enabled via @option{mlock=on}
>> +(enabled by default).
>> +ETEXI
>> +
>> DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
>> "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
>> STEXI
>> diff --git a/vl.c b/vl.c
>> index 1355f69..c16c8ad 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -491,6 +491,18 @@ static QemuOptsList qemu_object_opts = {
>> },
>> };
>>
>> +static QemuOptsList qemu_realtime_opts = {
>> + .name = "realtime",
>> + .head = QTAILQ_HEAD_INITIALIZER(qemu_realtime_opts.head),
>> + .desc = {
>> + {
>> + .name = "mlock",
>> + .type = QEMU_OPT_BOOL,
>> + },
>> + { /* end of list */ }
>> + },
>> +};
>> +
>> const char *qemu_get_vm_name(void)
>> {
>> return qemu_name;
>> @@ -1384,6 +1396,17 @@ static void smp_parse(const char *optarg)
>> max_cpus = smp_cpus;
>> }
>>
>> +static void configure_realtime(QemuOpts *opts) {
>> + bool is_mlock;
>> +
>> + is_mlock = qemu_opt_get_bool(opts, "mlock", true);
>> +
>> + if (is_mlock) {
>> + os_mlock();
>> + }
>> +}
>> +
>> /***********************************************************/
>> /* USB devices */
>>
>> @@ -2860,6 +2883,7 @@ int main(int argc, char **argv, char **envp)
>> qemu_add_opts(&qemu_sandbox_opts);
>> qemu_add_opts(&qemu_add_fd_opts);
>> qemu_add_opts(&qemu_object_opts);
>> + qemu_add_opts(&qemu_realtime_opts);
>>
>> runstate_init();
>>
>> @@ -3806,6 +3830,13 @@ int main(int argc, char **argv, char **envp)
>> exit(1);
>> }
>> break;
>> + case QEMU_OPTION_realtime:
>> + opts = qemu_opts_parse(qemu_find_opts("realtime"), optarg,
>> 0);
>> + if (!opts) {
>> + exit(1);
>> + }
>> + configure_realtime(opts);
>> + break;
>> default:
>> os_parse_cmd_args(popt->index, optarg);
>> }
>>
>
>
