| Message ID | 20241009234610.27039-9-yichen.wang@bytedance.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Use Intel DSA accelerator to offload zero page checking in multifd live migration. | expand |
* Yichen Wang (yichen.wang@bytedance.com) wrote: > From: Hao Xiang <hao.xiang@linux.dev> Please split the cpuid stuff out into a separate patch; it feels like it should be in some x86 specific place. > Intel DSA offloading is an optional feature that turns on if > proper hardware and software stack is available. To turn on > DSA offloading in multifd live migration by setting: > > zero-page-detection=dsa-accel > dsa-accel-path=[dsa_dev_path1] [dsa_dev_path2] ... [dsa_dev_pathX] I'd like to suggest changing that to: accel-path=dsa:dev_path1 dsa:dev_path2 somethingelse:dev_path2 etc that means we don't need a new option when someone adds a different accelerator. Dave > This feature is turned off by default. > > Signed-off-by: Hao Xiang <hao.xiang@linux.dev> > Signed-off-by: Yichen Wang <yichen.wang@bytedance.com> > --- > hmp-commands.hx | 2 +- > include/qemu/dsa.h | 13 +++++++++++++ > migration/migration-hmp-cmds.c | 19 ++++++++++++++++++- > migration/options.c | 30 ++++++++++++++++++++++++++++++ > migration/options.h | 1 + > qapi/migration.json | 32 ++++++++++++++++++++++++++++---- > util/dsa.c | 31 +++++++++++++++++++++++++++++++ > 7 files changed, 122 insertions(+), 6 deletions(-) > > diff --git a/hmp-commands.hx b/hmp-commands.hx > index 06746f0afc..0e04eac7c7 100644 > --- a/hmp-commands.hx > +++ b/hmp-commands.hx > @@ -1009,7 +1009,7 @@ ERST > > { > .name = "migrate_set_parameter", > - .args_type = "parameter:s,value:s", > + .args_type = "parameter:s,value:S", Can you show the case you need this for? Dave > .params = "parameter value", > .help = "Set the parameter for migration", > .cmd = hmp_migrate_set_parameter, > diff --git a/include/qemu/dsa.h b/include/qemu/dsa.h > index a3b502ee41..b1bb6daad2 100644 > --- a/include/qemu/dsa.h > +++ b/include/qemu/dsa.h > @@ -100,6 +100,13 @@ void qemu_dsa_stop(void); > */ > void qemu_dsa_cleanup(void); > > +/** > + * @brief Check if DSA is supported. > + * > + * @return True if DSA is supported, otherwise false. > + */ > +bool qemu_dsa_is_supported(void); > + > /** > * @brief Check if DSA is running. > * > @@ -141,6 +148,12 @@ buffer_is_zero_dsa_batch_sync(QemuDsaBatchTask *batch_task, > > typedef struct QemuDsaBatchTask {} QemuDsaBatchTask; > > +static inline bool qemu_dsa_is_supported(void) > +{ > + return false; > +} > + > + > static inline bool qemu_dsa_is_running(void) > { > return false; > diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c > index 20d1a6e219..983f13b73c 100644 > --- a/migration/migration-hmp-cmds.c > +++ b/migration/migration-hmp-cmds.c > @@ -312,7 +312,16 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) > monitor_printf(mon, "%s: '%s'\n", > MigrationParameter_str(MIGRATION_PARAMETER_TLS_AUTHZ), > params->tls_authz); > - > + if (params->has_dsa_accel_path) { > + strList *dsa_accel_path = params->dsa_accel_path; > + monitor_printf(mon, "%s:", > + MigrationParameter_str(MIGRATION_PARAMETER_DSA_ACCEL_PATH)); > + while (dsa_accel_path) { > + monitor_printf(mon, " '%s'", dsa_accel_path->value); > + dsa_accel_path = dsa_accel_path->next; > + } > + monitor_printf(mon, "\n"); > + } > if (params->has_block_bitmap_mapping) { > const BitmapMigrationNodeAliasList *bmnal; > > @@ -563,6 +572,14 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) > p->has_x_checkpoint_delay = true; > visit_type_uint32(v, param, &p->x_checkpoint_delay, &err); > break; > + case MIGRATION_PARAMETER_DSA_ACCEL_PATH: > + p->has_dsa_accel_path = true; > + g_autofree char **strv = g_strsplit(valuestr ? : "", " ", -1); > + strList **tail = &p->dsa_accel_path; > + for (int i = 0; strv[i]; i++) { > + QAPI_LIST_APPEND(tail, strv[i]); > + } > + break; > case MIGRATION_PARAMETER_MULTIFD_CHANNELS: > p->has_multifd_channels = true; > visit_type_uint8(v, param, &p->multifd_channels, &err); > diff --git a/migration/options.c b/migration/options.c > index 147cd2b8fd..a0b3a7d291 100644 > --- a/migration/options.c > +++ b/migration/options.c > @@ -13,6 +13,7 @@ > > #include "qemu/osdep.h" > #include "qemu/error-report.h" > +#include "qemu/dsa.h" > #include "exec/target_page.h" > #include "qapi/clone-visitor.h" > #include "qapi/error.h" > @@ -832,6 +833,13 @@ const char *migrate_tls_creds(void) > return s->parameters.tls_creds; > } > > +const strList *migrate_dsa_accel_path(void) > +{ > + MigrationState *s = migrate_get_current(); > + > + return s->parameters.dsa_accel_path; > +} > + > const char *migrate_tls_hostname(void) > { > MigrationState *s = migrate_get_current(); > @@ -945,6 +953,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) > params->zero_page_detection = s->parameters.zero_page_detection; > params->has_direct_io = true; > params->direct_io = s->parameters.direct_io; > + params->has_dsa_accel_path = true; > + params->dsa_accel_path = QAPI_CLONE(strList, s->parameters.dsa_accel_path); > > return params; > } > @@ -953,6 +963,7 @@ void migrate_params_init(MigrationParameters *params) > { > params->tls_hostname = g_strdup(""); > params->tls_creds = g_strdup(""); > + params->dsa_accel_path = NULL; > > /* Set has_* up only for parameter checks */ > params->has_throttle_trigger_threshold = true; > @@ -1165,6 +1176,14 @@ bool migrate_params_check(MigrationParameters *params, Error **errp) > return false; > } > > + if (params->has_zero_page_detection && > + params->zero_page_detection == ZERO_PAGE_DETECTION_DSA_ACCEL) { > + if (!qemu_dsa_is_supported()) { > + error_setg(errp, "DSA acceleration is not supported."); > + return false; > + } > + } > + > return true; > } > > @@ -1278,6 +1297,11 @@ static void migrate_params_test_apply(MigrateSetParameters *params, > if (params->has_direct_io) { > dest->direct_io = params->direct_io; > } > + > + if (params->has_dsa_accel_path) { > + dest->has_dsa_accel_path = true; > + dest->dsa_accel_path = params->dsa_accel_path; > + } > } > > static void migrate_params_apply(MigrateSetParameters *params, Error **errp) > @@ -1410,6 +1434,12 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) > if (params->has_direct_io) { > s->parameters.direct_io = params->direct_io; > } > + if (params->has_dsa_accel_path) { > + qapi_free_strList(s->parameters.dsa_accel_path); > + s->parameters.has_dsa_accel_path = true; > + s->parameters.dsa_accel_path = > + QAPI_CLONE(strList, params->dsa_accel_path); > + } > } > > void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp) > diff --git a/migration/options.h b/migration/options.h > index a0bd6edc06..8198b220bd 100644 > --- a/migration/options.h > +++ b/migration/options.h > @@ -86,6 +86,7 @@ const char *migrate_tls_creds(void); > const char *migrate_tls_hostname(void); > uint64_t migrate_xbzrle_cache_size(void); > ZeroPageDetection migrate_zero_page_detection(void); > +const strList *migrate_dsa_accel_path(void); > > /* parameters helpers */ > > diff --git a/qapi/migration.json b/qapi/migration.json > index b66cccf107..d8b42ceae6 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -626,10 +626,14 @@ > # multifd migration is enabled, else in the main migration thread > # as for @legacy. > # > +# @dsa-accel: Perform zero page checking with the DSA accelerator > +# offloading in multifd sender thread if multifd migration is > +# enabled, else in the main migration thread as for @legacy. > +# > # Since: 9.0 > ## > { 'enum': 'ZeroPageDetection', > - 'data': [ 'none', 'legacy', 'multifd' ] } > + 'data': [ 'none', 'legacy', 'multifd', 'dsa-accel' ] } > > ## > # @BitmapMigrationBitmapAliasTransform: > @@ -837,6 +841,12 @@ > # See description in @ZeroPageDetection. Default is 'multifd'. > # (since 9.0) > # > +# @dsa-accel-path: If enabled, use DSA accelerator offloading for > +# certain memory operations. Enable DSA accelerator for zero > +# page detection offloading by setting the @zero-page-detection > +# to dsa-accel. This parameter defines the dsa device path, and > +# defaults to an empty list. (Since 9.2) > +# > # @direct-io: Open migration files with O_DIRECT when possible. This > # only has effect if the @mapped-ram capability is enabled. > # (Since 9.1) > @@ -855,7 +865,7 @@ > 'cpu-throttle-initial', 'cpu-throttle-increment', > 'cpu-throttle-tailslow', > 'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth', > - 'avail-switchover-bandwidth', 'downtime-limit', > + 'avail-switchover-bandwidth', 'downtime-limit', 'dsa-accel-path', > { 'name': 'x-checkpoint-delay', 'features': [ 'unstable' ] }, > 'multifd-channels', > 'xbzrle-cache-size', 'max-postcopy-bandwidth', > @@ -1018,6 +1028,12 @@ > # See description in @ZeroPageDetection. Default is 'multifd'. > # (since 9.0) > # > +# @dsa-accel-path: If enabled, use DSA accelerator offloading for > +# certain memory operations. Enable DSA accelerator for zero > +# page detection offloading by setting the @zero-page-detection > +# to dsa-accel. This parameter defines the dsa device path, and > +# defaults to an empty list. (Since 9.2) > +# > # @direct-io: Open migration files with O_DIRECT when possible. This > # only has effect if the @mapped-ram capability is enabled. > # (Since 9.1) > @@ -1063,7 +1079,8 @@ > '*vcpu-dirty-limit': 'uint64', > '*mode': 'MigMode', > '*zero-page-detection': 'ZeroPageDetection', > - '*direct-io': 'bool' } } > + '*direct-io': 'bool', > + '*dsa-accel-path': [ 'str' ] } } > > ## > # @migrate-set-parameters: > @@ -1228,6 +1245,12 @@ > # See description in @ZeroPageDetection. Default is 'multifd'. > # (since 9.0) > # > +# @dsa-accel-path: If enabled, use DSA accelerator offloading for > +# certain memory operations. Enable DSA accelerator for zero > +# page detection offloading by setting the @zero-page-detection > +# to dsa-accel. This parameter defines the dsa device path, and > +# defaults to an empty list. (Since 9.2) > +# > # @direct-io: Open migration files with O_DIRECT when possible. This > # only has effect if the @mapped-ram capability is enabled. > # (Since 9.1) > @@ -1270,7 +1293,8 @@ > '*vcpu-dirty-limit': 'uint64', > '*mode': 'MigMode', > '*zero-page-detection': 'ZeroPageDetection', > - '*direct-io': 'bool' } } > + '*direct-io': 'bool', > + '*dsa-accel-path': [ 'str' ] } } > > ## > # @query-migrate-parameters: > diff --git a/util/dsa.c b/util/dsa.c > index cbaa47c360..eeede3c0c7 100644 > --- a/util/dsa.c > +++ b/util/dsa.c > @@ -23,6 +23,7 @@ > #include "qemu/bswap.h" > #include "qemu/error-report.h" > #include "qemu/rcu.h" > +#include <cpuid.h> > > #pragma GCC push_options > #pragma GCC target("enqcmd") > @@ -691,6 +692,36 @@ static void dsa_completion_thread_stop(void *opaque) > qemu_sem_destroy(&thread_context->sem_init_done); > } > > +/** > + * @brief Check if DSA is supported. > + * > + * @return True if DSA is supported, otherwise false. > + */ > +bool qemu_dsa_is_supported(void) > +{ > + /* > + * movdir64b is indicated by bit 28 of ecx in CPUID leaf 7, subleaf 0. > + * enqcmd is indicated by bit 29 of ecx in CPUID leaf 7, subleaf 0. > + * Doc: https://cdrdv2-public.intel.com/819680/architecture-instruction-\ > + * set-extensions-programming-reference.pdf > + */ > + uint32_t eax, ebx, ecx, edx; > + bool movedirb_enabled; > + bool enqcmd_enabled; > + > + __get_cpuid_count(7, 0, &eax, &ebx, &ecx, &edx); > + movedirb_enabled = (ecx >> 28) & 0x1; > + if (!movedirb_enabled) { > + return false; > + } > + enqcmd_enabled = (ecx >> 29) & 0x1; > + if (!enqcmd_enabled) { > + return false; > + } > + > + return true; > +} > + > /** > * @brief Check if DSA is running. > * > -- > Yichen Wang >
On Fri, Oct 11, 2024 at 10:14 AM Dr. David Alan Gilbert <dave@treblig.org> wrote: > > * Yichen Wang (yichen.wang@bytedance.com) wrote: > > From: Hao Xiang <hao.xiang@linux.dev> > > Please split the cpuid stuff out into a separate patch; it feels like > it should be in some x86 specific place. DSA is an Intel feature/device, and it only makes sense on x86. I mean, dsa.c already implies that it is a x86 specific feature. So I guess keeping it in the dsa.c is a better option? > > > Intel DSA offloading is an optional feature that turns on if > > proper hardware and software stack is available. To turn on > > DSA offloading in multifd live migration by setting: > > > > zero-page-detection=dsa-accel > > dsa-accel-path=[dsa_dev_path1] [dsa_dev_path2] ... [dsa_dev_pathX] > > I'd like to suggest changing that to: > > accel-path=dsa:dev_path1 dsa:dev_path2 somethingelse:dev_path2 etc > > that means we don't need a new option when someone adds a different > accelerator. It all depends on the implementation of "other accelerators". I am OK with this change if you believe that is better. > > Dave > > This feature is turned off by default. > > > > Signed-off-by: Hao Xiang <hao.xiang@linux.dev> > > Signed-off-by: Yichen Wang <yichen.wang@bytedance.com> > > --- > > hmp-commands.hx | 2 +- > > include/qemu/dsa.h | 13 +++++++++++++ > > migration/migration-hmp-cmds.c | 19 ++++++++++++++++++- > > migration/options.c | 30 ++++++++++++++++++++++++++++++ > > migration/options.h | 1 + > > qapi/migration.json | 32 ++++++++++++++++++++++++++++---- > > util/dsa.c | 31 +++++++++++++++++++++++++++++++ > > 7 files changed, 122 insertions(+), 6 deletions(-) > > > > diff --git a/hmp-commands.hx b/hmp-commands.hx > > index 06746f0afc..0e04eac7c7 100644 > > --- a/hmp-commands.hx > > +++ b/hmp-commands.hx > > @@ -1009,7 +1009,7 @@ ERST > > > > { > > .name = "migrate_set_parameter", > > - .args_type = "parameter:s,value:s", > > + .args_type = "parameter:s,value:S", > > Can you show the case you need this for? > That is used for pass a strList in the QEMU CLI. Without this change, I cannot do: migrate_set_parameter dsa-accel-path /dev/dsa/wq0.1 /dev/dsa/wq0.1 and it will complain. > Dave > > > .params = "parameter value", > > .help = "Set the parameter for migration", > > .cmd = hmp_migrate_set_parameter, > > diff --git a/include/qemu/dsa.h b/include/qemu/dsa.h > > index a3b502ee41..b1bb6daad2 100644 > > --- a/include/qemu/dsa.h > > +++ b/include/qemu/dsa.h > > @@ -100,6 +100,13 @@ void qemu_dsa_stop(void); > > */ > > void qemu_dsa_cleanup(void); > > > > +/** > > + * @brief Check if DSA is supported. > > + * > > + * @return True if DSA is supported, otherwise false. > > + */ > > +bool qemu_dsa_is_supported(void); > > + > > /** > > * @brief Check if DSA is running. > > * > > @@ -141,6 +148,12 @@ buffer_is_zero_dsa_batch_sync(QemuDsaBatchTask *batch_task, > > > > typedef struct QemuDsaBatchTask {} QemuDsaBatchTask; > > > > +static inline bool qemu_dsa_is_supported(void) > > +{ > > + return false; > > +} > > + > > + > > static inline bool qemu_dsa_is_running(void) > > { > > return false; > > diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c > > index 20d1a6e219..983f13b73c 100644 > > --- a/migration/migration-hmp-cmds.c > > +++ b/migration/migration-hmp-cmds.c > > @@ -312,7 +312,16 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) > > monitor_printf(mon, "%s: '%s'\n", > > MigrationParameter_str(MIGRATION_PARAMETER_TLS_AUTHZ), > > params->tls_authz); > > - > > + if (params->has_dsa_accel_path) { > > + strList *dsa_accel_path = params->dsa_accel_path; > > + monitor_printf(mon, "%s:", > > + MigrationParameter_str(MIGRATION_PARAMETER_DSA_ACCEL_PATH)); > > + while (dsa_accel_path) { > > + monitor_printf(mon, " '%s'", dsa_accel_path->value); > > + dsa_accel_path = dsa_accel_path->next; > > + } > > + monitor_printf(mon, "\n"); > > + } > > if (params->has_block_bitmap_mapping) { > > const BitmapMigrationNodeAliasList *bmnal; > > > > @@ -563,6 +572,14 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) > > p->has_x_checkpoint_delay = true; > > visit_type_uint32(v, param, &p->x_checkpoint_delay, &err); > > break; > > + case MIGRATION_PARAMETER_DSA_ACCEL_PATH: > > + p->has_dsa_accel_path = true; > > + g_autofree char **strv = g_strsplit(valuestr ? : "", " ", -1); > > + strList **tail = &p->dsa_accel_path; > > + for (int i = 0; strv[i]; i++) { > > + QAPI_LIST_APPEND(tail, strv[i]); > > + } > > + break; > > case MIGRATION_PARAMETER_MULTIFD_CHANNELS: > > p->has_multifd_channels = true; > > visit_type_uint8(v, param, &p->multifd_channels, &err); > > diff --git a/migration/options.c b/migration/options.c > > index 147cd2b8fd..a0b3a7d291 100644 > > --- a/migration/options.c > > +++ b/migration/options.c > > @@ -13,6 +13,7 @@ > > > > #include "qemu/osdep.h" > > #include "qemu/error-report.h" > > +#include "qemu/dsa.h" > > #include "exec/target_page.h" > > #include "qapi/clone-visitor.h" > > #include "qapi/error.h" > > @@ -832,6 +833,13 @@ const char *migrate_tls_creds(void) > > return s->parameters.tls_creds; > > } > > > > +const strList *migrate_dsa_accel_path(void) > > +{ > > + MigrationState *s = migrate_get_current(); > > + > > + return s->parameters.dsa_accel_path; > > +} > > + > > const char *migrate_tls_hostname(void) > > { > > MigrationState *s = migrate_get_current(); > > @@ -945,6 +953,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) > > params->zero_page_detection = s->parameters.zero_page_detection; > > params->has_direct_io = true; > > params->direct_io = s->parameters.direct_io; > > + params->has_dsa_accel_path = true; > > + params->dsa_accel_path = QAPI_CLONE(strList, s->parameters.dsa_accel_path); > > > > return params; > > } > > @@ -953,6 +963,7 @@ void migrate_params_init(MigrationParameters *params) > > { > > params->tls_hostname = g_strdup(""); > > params->tls_creds = g_strdup(""); > > + params->dsa_accel_path = NULL; > > > > /* Set has_* up only for parameter checks */ > > params->has_throttle_trigger_threshold = true; > > @@ -1165,6 +1176,14 @@ bool migrate_params_check(MigrationParameters *params, Error **errp) > > return false; > > } > > > > + if (params->has_zero_page_detection && > > + params->zero_page_detection == ZERO_PAGE_DETECTION_DSA_ACCEL) { > > + if (!qemu_dsa_is_supported()) { > > + error_setg(errp, "DSA acceleration is not supported."); > > + return false; > > + } > > + } > > + > > return true; > > } > > > > @@ -1278,6 +1297,11 @@ static void migrate_params_test_apply(MigrateSetParameters *params, > > if (params->has_direct_io) { > > dest->direct_io = params->direct_io; > > } > > + > > + if (params->has_dsa_accel_path) { > > + dest->has_dsa_accel_path = true; > > + dest->dsa_accel_path = params->dsa_accel_path; > > + } > > } > > > > static void migrate_params_apply(MigrateSetParameters *params, Error **errp) > > @@ -1410,6 +1434,12 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) > > if (params->has_direct_io) { > > s->parameters.direct_io = params->direct_io; > > } > > + if (params->has_dsa_accel_path) { > > + qapi_free_strList(s->parameters.dsa_accel_path); > > + s->parameters.has_dsa_accel_path = true; > > + s->parameters.dsa_accel_path = > > + QAPI_CLONE(strList, params->dsa_accel_path); > > + } > > } > > > > void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp) > > diff --git a/migration/options.h b/migration/options.h > > index a0bd6edc06..8198b220bd 100644 > > --- a/migration/options.h > > +++ b/migration/options.h > > @@ -86,6 +86,7 @@ const char *migrate_tls_creds(void); > > const char *migrate_tls_hostname(void); > > uint64_t migrate_xbzrle_cache_size(void); > > ZeroPageDetection migrate_zero_page_detection(void); > > +const strList *migrate_dsa_accel_path(void); > > > > /* parameters helpers */ > > > > diff --git a/qapi/migration.json b/qapi/migration.json > > index b66cccf107..d8b42ceae6 100644 > > --- a/qapi/migration.json > > +++ b/qapi/migration.json > > @@ -626,10 +626,14 @@ > > # multifd migration is enabled, else in the main migration thread > > # as for @legacy. > > # > > +# @dsa-accel: Perform zero page checking with the DSA accelerator > > +# offloading in multifd sender thread if multifd migration is > > +# enabled, else in the main migration thread as for @legacy. > > +# > > # Since: 9.0 > > ## > > { 'enum': 'ZeroPageDetection', > > - 'data': [ 'none', 'legacy', 'multifd' ] } > > + 'data': [ 'none', 'legacy', 'multifd', 'dsa-accel' ] } > > > > ## > > # @BitmapMigrationBitmapAliasTransform: > > @@ -837,6 +841,12 @@ > > # See description in @ZeroPageDetection. Default is 'multifd'. > > # (since 9.0) > > # > > +# @dsa-accel-path: If enabled, use DSA accelerator offloading for > > +# certain memory operations. Enable DSA accelerator for zero > > +# page detection offloading by setting the @zero-page-detection > > +# to dsa-accel. This parameter defines the dsa device path, and > > +# defaults to an empty list. (Since 9.2) > > +# > > # @direct-io: Open migration files with O_DIRECT when possible. This > > # only has effect if the @mapped-ram capability is enabled. > > # (Since 9.1) > > @@ -855,7 +865,7 @@ > > 'cpu-throttle-initial', 'cpu-throttle-increment', > > 'cpu-throttle-tailslow', > > 'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth', > > - 'avail-switchover-bandwidth', 'downtime-limit', > > + 'avail-switchover-bandwidth', 'downtime-limit', 'dsa-accel-path', > > { 'name': 'x-checkpoint-delay', 'features': [ 'unstable' ] }, > > 'multifd-channels', > > 'xbzrle-cache-size', 'max-postcopy-bandwidth', > > @@ -1018,6 +1028,12 @@ > > # See description in @ZeroPageDetection. Default is 'multifd'. > > # (since 9.0) > > # > > +# @dsa-accel-path: If enabled, use DSA accelerator offloading for > > +# certain memory operations. Enable DSA accelerator for zero > > +# page detection offloading by setting the @zero-page-detection > > +# to dsa-accel. This parameter defines the dsa device path, and > > +# defaults to an empty list. (Since 9.2) > > +# > > # @direct-io: Open migration files with O_DIRECT when possible. This > > # only has effect if the @mapped-ram capability is enabled. > > # (Since 9.1) > > @@ -1063,7 +1079,8 @@ > > '*vcpu-dirty-limit': 'uint64', > > '*mode': 'MigMode', > > '*zero-page-detection': 'ZeroPageDetection', > > - '*direct-io': 'bool' } } > > + '*direct-io': 'bool', > > + '*dsa-accel-path': [ 'str' ] } } > > > > ## > > # @migrate-set-parameters: > > @@ -1228,6 +1245,12 @@ > > # See description in @ZeroPageDetection. Default is 'multifd'. > > # (since 9.0) > > # > > +# @dsa-accel-path: If enabled, use DSA accelerator offloading for > > +# certain memory operations. Enable DSA accelerator for zero > > +# page detection offloading by setting the @zero-page-detection > > +# to dsa-accel. This parameter defines the dsa device path, and > > +# defaults to an empty list. (Since 9.2) > > +# > > # @direct-io: Open migration files with O_DIRECT when possible. This > > # only has effect if the @mapped-ram capability is enabled. > > # (Since 9.1) > > @@ -1270,7 +1293,8 @@ > > '*vcpu-dirty-limit': 'uint64', > > '*mode': 'MigMode', > > '*zero-page-detection': 'ZeroPageDetection', > > - '*direct-io': 'bool' } } > > + '*direct-io': 'bool', > > + '*dsa-accel-path': [ 'str' ] } } > > > > ## > > # @query-migrate-parameters: > > diff --git a/util/dsa.c b/util/dsa.c > > index cbaa47c360..eeede3c0c7 100644 > > --- a/util/dsa.c > > +++ b/util/dsa.c > > @@ -23,6 +23,7 @@ > > #include "qemu/bswap.h" > > #include "qemu/error-report.h" > > #include "qemu/rcu.h" > > +#include <cpuid.h> > > > > #pragma GCC push_options > > #pragma GCC target("enqcmd") > > @@ -691,6 +692,36 @@ static void dsa_completion_thread_stop(void *opaque) > > qemu_sem_destroy(&thread_context->sem_init_done); > > } > > > > +/** > > + * @brief Check if DSA is supported. > > + * > > + * @return True if DSA is supported, otherwise false. > > + */ > > +bool qemu_dsa_is_supported(void) > > +{ > > + /* > > + * movdir64b is indicated by bit 28 of ecx in CPUID leaf 7, subleaf 0. > > + * enqcmd is indicated by bit 29 of ecx in CPUID leaf 7, subleaf 0. > > + * Doc: https://cdrdv2-public.intel.com/819680/architecture-instruction-\ > > + * set-extensions-programming-reference.pdf > > + */ > > + uint32_t eax, ebx, ecx, edx; > > + bool movedirb_enabled; > > + bool enqcmd_enabled; > > + > > + __get_cpuid_count(7, 0, &eax, &ebx, &ecx, &edx); > > + movedirb_enabled = (ecx >> 28) & 0x1; > > + if (!movedirb_enabled) { > > + return false; > > + } > > + enqcmd_enabled = (ecx >> 29) & 0x1; > > + if (!enqcmd_enabled) { > > + return false; > > + } > > + > > + return true; > > +} > > + > > /** > > * @brief Check if DSA is running. > > * > > -- > > Yichen Wang > > > -- > -----Open up your eyes, open up your mind, open up your code ------- > / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ > \ dave @ treblig.org | | In Hex / > \ _________________________|_____ http://www.treblig.org |_______/
* Yichen Wang (yichen.wang@bytedance.com) wrote: > On Fri, Oct 11, 2024 at 10:14 AM Dr. David Alan Gilbert > <dave@treblig.org> wrote: > > > > * Yichen Wang (yichen.wang@bytedance.com) wrote: > > > From: Hao Xiang <hao.xiang@linux.dev> > > > > Please split the cpuid stuff out into a separate patch; it feels like > > it should be in some x86 specific place. > > DSA is an Intel feature/device, and it only makes sense on x86. I > mean, dsa.c already implies that it is a x86 specific feature. So I > guess keeping it in the dsa.c is a better option? Yes, the dsa.c might be OK; we just shouldn't have very x86 specific code in the other places. > > > > > Intel DSA offloading is an optional feature that turns on if > > > proper hardware and software stack is available. To turn on > > > DSA offloading in multifd live migration by setting: > > > > > > zero-page-detection=dsa-accel > > > dsa-accel-path=[dsa_dev_path1] [dsa_dev_path2] ... [dsa_dev_pathX] > > > > I'd like to suggest changing that to: > > > > accel-path=dsa:dev_path1 dsa:dev_path2 somethingelse:dev_path2 etc > > > > that means we don't need a new option when someone adds a different > > accelerator. > > It all depends on the implementation of "other accelerators". I am OK > with this change if you believe that is better. I think so; it makes no assumption about what any other accelerator might need, but means we don't need to add yet another command for them. > > > > Dave > > > This feature is turned off by default. > > > > > > Signed-off-by: Hao Xiang <hao.xiang@linux.dev> > > > Signed-off-by: Yichen Wang <yichen.wang@bytedance.com> > > > --- > > > hmp-commands.hx | 2 +- > > > include/qemu/dsa.h | 13 +++++++++++++ > > > migration/migration-hmp-cmds.c | 19 ++++++++++++++++++- > > > migration/options.c | 30 ++++++++++++++++++++++++++++++ > > > migration/options.h | 1 + > > > qapi/migration.json | 32 ++++++++++++++++++++++++++++---- > > > util/dsa.c | 31 +++++++++++++++++++++++++++++++ > > > 7 files changed, 122 insertions(+), 6 deletions(-) > > > > > > diff --git a/hmp-commands.hx b/hmp-commands.hx > > > index 06746f0afc..0e04eac7c7 100644 > > > --- a/hmp-commands.hx > > > +++ b/hmp-commands.hx > > > @@ -1009,7 +1009,7 @@ ERST > > > > > > { > > > .name = "migrate_set_parameter", > > > - .args_type = "parameter:s,value:s", > > > + .args_type = "parameter:s,value:S", > > > > Can you show the case you need this for? > > > > That is used for pass a strList in the QEMU CLI. Without this change, > I cannot do: > migrate_set_parameter dsa-accel-path /dev/dsa/wq0.1 /dev/dsa/wq0.1 > and it will complain. OK, please make sure you get a sensible error if you try and pass a string list to one of the existing parameters. Dave > > Dave > > > > > .params = "parameter value", > > > .help = "Set the parameter for migration", > > > .cmd = hmp_migrate_set_parameter, > > > diff --git a/include/qemu/dsa.h b/include/qemu/dsa.h > > > index a3b502ee41..b1bb6daad2 100644 > > > --- a/include/qemu/dsa.h > > > +++ b/include/qemu/dsa.h > > > @@ -100,6 +100,13 @@ void qemu_dsa_stop(void); > > > */ > > > void qemu_dsa_cleanup(void); > > > > > > +/** > > > + * @brief Check if DSA is supported. > > > + * > > > + * @return True if DSA is supported, otherwise false. > > > + */ > > > +bool qemu_dsa_is_supported(void); > > > + > > > /** > > > * @brief Check if DSA is running. > > > * > > > @@ -141,6 +148,12 @@ buffer_is_zero_dsa_batch_sync(QemuDsaBatchTask *batch_task, > > > > > > typedef struct QemuDsaBatchTask {} QemuDsaBatchTask; > > > > > > +static inline bool qemu_dsa_is_supported(void) > > > +{ > > > + return false; > > > +} > > > + > > > + > > > static inline bool qemu_dsa_is_running(void) > > > { > > > return false; > > > diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c > > > index 20d1a6e219..983f13b73c 100644 > > > --- a/migration/migration-hmp-cmds.c > > > +++ b/migration/migration-hmp-cmds.c > > > @@ -312,7 +312,16 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) > > > monitor_printf(mon, "%s: '%s'\n", > > > MigrationParameter_str(MIGRATION_PARAMETER_TLS_AUTHZ), > > > params->tls_authz); > > > - > > > + if (params->has_dsa_accel_path) { > > > + strList *dsa_accel_path = params->dsa_accel_path; > > > + monitor_printf(mon, "%s:", > > > + MigrationParameter_str(MIGRATION_PARAMETER_DSA_ACCEL_PATH)); > > > + while (dsa_accel_path) { > > > + monitor_printf(mon, " '%s'", dsa_accel_path->value); > > > + dsa_accel_path = dsa_accel_path->next; > > > + } > > > + monitor_printf(mon, "\n"); > > > + } > > > if (params->has_block_bitmap_mapping) { > > > const BitmapMigrationNodeAliasList *bmnal; > > > > > > @@ -563,6 +572,14 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) > > > p->has_x_checkpoint_delay = true; > > > visit_type_uint32(v, param, &p->x_checkpoint_delay, &err); > > > break; > > > + case MIGRATION_PARAMETER_DSA_ACCEL_PATH: > > > + p->has_dsa_accel_path = true; > > > + g_autofree char **strv = g_strsplit(valuestr ? : "", " ", -1); > > > + strList **tail = &p->dsa_accel_path; > > > + for (int i = 0; strv[i]; i++) { > > > + QAPI_LIST_APPEND(tail, strv[i]); > > > + } > > > + break; > > > case MIGRATION_PARAMETER_MULTIFD_CHANNELS: > > > p->has_multifd_channels = true; > > > visit_type_uint8(v, param, &p->multifd_channels, &err); > > > diff --git a/migration/options.c b/migration/options.c > > > index 147cd2b8fd..a0b3a7d291 100644 > > > --- a/migration/options.c > > > +++ b/migration/options.c > > > @@ -13,6 +13,7 @@ > > > > > > #include "qemu/osdep.h" > > > #include "qemu/error-report.h" > > > +#include "qemu/dsa.h" > > > #include "exec/target_page.h" > > > #include "qapi/clone-visitor.h" > > > #include "qapi/error.h" > > > @@ -832,6 +833,13 @@ const char *migrate_tls_creds(void) > > > return s->parameters.tls_creds; > > > } > > > > > > +const strList *migrate_dsa_accel_path(void) > > > +{ > > > + MigrationState *s = migrate_get_current(); > > > + > > > + return s->parameters.dsa_accel_path; > > > +} > > > + > > > const char *migrate_tls_hostname(void) > > > { > > > MigrationState *s = migrate_get_current(); > > > @@ -945,6 +953,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) > > > params->zero_page_detection = s->parameters.zero_page_detection; > > > params->has_direct_io = true; > > > params->direct_io = s->parameters.direct_io; > > > + params->has_dsa_accel_path = true; > > > + params->dsa_accel_path = QAPI_CLONE(strList, s->parameters.dsa_accel_path); > > > > > > return params; > > > } > > > @@ -953,6 +963,7 @@ void migrate_params_init(MigrationParameters *params) > > > { > > > params->tls_hostname = g_strdup(""); > > > params->tls_creds = g_strdup(""); > > > + params->dsa_accel_path = NULL; > > > > > > /* Set has_* up only for parameter checks */ > > > params->has_throttle_trigger_threshold = true; > > > @@ -1165,6 +1176,14 @@ bool migrate_params_check(MigrationParameters *params, Error **errp) > > > return false; > > > } > > > > > > + if (params->has_zero_page_detection && > > > + params->zero_page_detection == ZERO_PAGE_DETECTION_DSA_ACCEL) { > > > + if (!qemu_dsa_is_supported()) { > > > + error_setg(errp, "DSA acceleration is not supported."); > > > + return false; > > > + } > > > + } > > > + > > > return true; > > > } > > > > > > @@ -1278,6 +1297,11 @@ static void migrate_params_test_apply(MigrateSetParameters *params, > > > if (params->has_direct_io) { > > > dest->direct_io = params->direct_io; > > > } > > > + > > > + if (params->has_dsa_accel_path) { > > > + dest->has_dsa_accel_path = true; > > > + dest->dsa_accel_path = params->dsa_accel_path; > > > + } > > > } > > > > > > static void migrate_params_apply(MigrateSetParameters *params, Error **errp) > > > @@ -1410,6 +1434,12 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) > > > if (params->has_direct_io) { > > > s->parameters.direct_io = params->direct_io; > > > } > > > + if (params->has_dsa_accel_path) { > > > + qapi_free_strList(s->parameters.dsa_accel_path); > > > + s->parameters.has_dsa_accel_path = true; > > > + s->parameters.dsa_accel_path = > > > + QAPI_CLONE(strList, params->dsa_accel_path); > > > + } > > > } > > > > > > void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp) > > > diff --git a/migration/options.h b/migration/options.h > > > index a0bd6edc06..8198b220bd 100644 > > > --- a/migration/options.h > > > +++ b/migration/options.h > > > @@ -86,6 +86,7 @@ const char *migrate_tls_creds(void); > > > const char *migrate_tls_hostname(void); > > > uint64_t migrate_xbzrle_cache_size(void); > > > ZeroPageDetection migrate_zero_page_detection(void); > > > +const strList *migrate_dsa_accel_path(void); > > > > > > /* parameters helpers */ > > > > > > diff --git a/qapi/migration.json b/qapi/migration.json > > > index b66cccf107..d8b42ceae6 100644 > > > --- a/qapi/migration.json > > > +++ b/qapi/migration.json > > > @@ -626,10 +626,14 @@ > > > # multifd migration is enabled, else in the main migration thread > > > # as for @legacy. > > > # > > > +# @dsa-accel: Perform zero page checking with the DSA accelerator > > > +# offloading in multifd sender thread if multifd migration is > > > +# enabled, else in the main migration thread as for @legacy. > > > +# > > > # Since: 9.0 > > > ## > > > { 'enum': 'ZeroPageDetection', > > > - 'data': [ 'none', 'legacy', 'multifd' ] } > > > + 'data': [ 'none', 'legacy', 'multifd', 'dsa-accel' ] } > > > > > > ## > > > # @BitmapMigrationBitmapAliasTransform: > > > @@ -837,6 +841,12 @@ > > > # See description in @ZeroPageDetection. Default is 'multifd'. > > > # (since 9.0) > > > # > > > +# @dsa-accel-path: If enabled, use DSA accelerator offloading for > > > +# certain memory operations. Enable DSA accelerator for zero > > > +# page detection offloading by setting the @zero-page-detection > > > +# to dsa-accel. This parameter defines the dsa device path, and > > > +# defaults to an empty list. (Since 9.2) > > > +# > > > # @direct-io: Open migration files with O_DIRECT when possible. This > > > # only has effect if the @mapped-ram capability is enabled. > > > # (Since 9.1) > > > @@ -855,7 +865,7 @@ > > > 'cpu-throttle-initial', 'cpu-throttle-increment', > > > 'cpu-throttle-tailslow', > > > 'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth', > > > - 'avail-switchover-bandwidth', 'downtime-limit', > > > + 'avail-switchover-bandwidth', 'downtime-limit', 'dsa-accel-path', > > > { 'name': 'x-checkpoint-delay', 'features': [ 'unstable' ] }, > > > 'multifd-channels', > > > 'xbzrle-cache-size', 'max-postcopy-bandwidth', > > > @@ -1018,6 +1028,12 @@ > > > # See description in @ZeroPageDetection. Default is 'multifd'. > > > # (since 9.0) > > > # > > > +# @dsa-accel-path: If enabled, use DSA accelerator offloading for > > > +# certain memory operations. Enable DSA accelerator for zero > > > +# page detection offloading by setting the @zero-page-detection > > > +# to dsa-accel. This parameter defines the dsa device path, and > > > +# defaults to an empty list. (Since 9.2) > > > +# > > > # @direct-io: Open migration files with O_DIRECT when possible. This > > > # only has effect if the @mapped-ram capability is enabled. > > > # (Since 9.1) > > > @@ -1063,7 +1079,8 @@ > > > '*vcpu-dirty-limit': 'uint64', > > > '*mode': 'MigMode', > > > '*zero-page-detection': 'ZeroPageDetection', > > > - '*direct-io': 'bool' } } > > > + '*direct-io': 'bool', > > > + '*dsa-accel-path': [ 'str' ] } } > > > > > > ## > > > # @migrate-set-parameters: > > > @@ -1228,6 +1245,12 @@ > > > # See description in @ZeroPageDetection. Default is 'multifd'. > > > # (since 9.0) > > > # > > > +# @dsa-accel-path: If enabled, use DSA accelerator offloading for > > > +# certain memory operations. Enable DSA accelerator for zero > > > +# page detection offloading by setting the @zero-page-detection > > > +# to dsa-accel. This parameter defines the dsa device path, and > > > +# defaults to an empty list. (Since 9.2) > > > +# > > > # @direct-io: Open migration files with O_DIRECT when possible. This > > > # only has effect if the @mapped-ram capability is enabled. > > > # (Since 9.1) > > > @@ -1270,7 +1293,8 @@ > > > '*vcpu-dirty-limit': 'uint64', > > > '*mode': 'MigMode', > > > '*zero-page-detection': 'ZeroPageDetection', > > > - '*direct-io': 'bool' } } > > > + '*direct-io': 'bool', > > > + '*dsa-accel-path': [ 'str' ] } } > > > > > > ## > > > # @query-migrate-parameters: > > > diff --git a/util/dsa.c b/util/dsa.c > > > index cbaa47c360..eeede3c0c7 100644 > > > --- a/util/dsa.c > > > +++ b/util/dsa.c > > > @@ -23,6 +23,7 @@ > > > #include "qemu/bswap.h" > > > #include "qemu/error-report.h" > > > #include "qemu/rcu.h" > > > +#include <cpuid.h> > > > > > > #pragma GCC push_options > > > #pragma GCC target("enqcmd") > > > @@ -691,6 +692,36 @@ static void dsa_completion_thread_stop(void *opaque) > > > qemu_sem_destroy(&thread_context->sem_init_done); > > > } > > > > > > +/** > > > + * @brief Check if DSA is supported. > > > + * > > > + * @return True if DSA is supported, otherwise false. > > > + */ > > > +bool qemu_dsa_is_supported(void) > > > +{ > > > + /* > > > + * movdir64b is indicated by bit 28 of ecx in CPUID leaf 7, subleaf 0. > > > + * enqcmd is indicated by bit 29 of ecx in CPUID leaf 7, subleaf 0. > > > + * Doc: https://cdrdv2-public.intel.com/819680/architecture-instruction-\ > > > + * set-extensions-programming-reference.pdf > > > + */ > > > + uint32_t eax, ebx, ecx, edx; > > > + bool movedirb_enabled; > > > + bool enqcmd_enabled; > > > + > > > + __get_cpuid_count(7, 0, &eax, &ebx, &ecx, &edx); > > > + movedirb_enabled = (ecx >> 28) & 0x1; > > > + if (!movedirb_enabled) { > > > + return false; > > > + } > > > + enqcmd_enabled = (ecx >> 29) & 0x1; > > > + if (!enqcmd_enabled) { > > > + return false; > > > + } > > > + > > > + return true; > > > +} > > > + > > > /** > > > * @brief Check if DSA is running. > > > * > > > -- > > > Yichen Wang > > > > > -- > > -----Open up your eyes, open up your mind, open up your code ------- > > / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ > > \ dave @ treblig.org | | In Hex / > > \ _________________________|_____ http://www.treblig.org |_______/
diff --git a/hmp-commands.hx b/hmp-commands.hx index 06746f0afc..0e04eac7c7 100644 --- a/hmp-commands.hx +++ b/hmp-commands.hx @@ -1009,7 +1009,7 @@ ERST { .name = "migrate_set_parameter", - .args_type = "parameter:s,value:s", + .args_type = "parameter:s,value:S", .params = "parameter value", .help = "Set the parameter for migration", .cmd = hmp_migrate_set_parameter, diff --git a/include/qemu/dsa.h b/include/qemu/dsa.h index a3b502ee41..b1bb6daad2 100644 --- a/include/qemu/dsa.h +++ b/include/qemu/dsa.h @@ -100,6 +100,13 @@ void qemu_dsa_stop(void); */ void qemu_dsa_cleanup(void); +/** + * @brief Check if DSA is supported. + * + * @return True if DSA is supported, otherwise false. + */ +bool qemu_dsa_is_supported(void); + /** * @brief Check if DSA is running. * @@ -141,6 +148,12 @@ buffer_is_zero_dsa_batch_sync(QemuDsaBatchTask *batch_task, typedef struct QemuDsaBatchTask {} QemuDsaBatchTask; +static inline bool qemu_dsa_is_supported(void) +{ + return false; +} + + static inline bool qemu_dsa_is_running(void) { return false; diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c index 20d1a6e219..983f13b73c 100644 --- a/migration/migration-hmp-cmds.c +++ b/migration/migration-hmp-cmds.c @@ -312,7 +312,16 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) monitor_printf(mon, "%s: '%s'\n", MigrationParameter_str(MIGRATION_PARAMETER_TLS_AUTHZ), params->tls_authz); - + if (params->has_dsa_accel_path) { + strList *dsa_accel_path = params->dsa_accel_path; + monitor_printf(mon, "%s:", + MigrationParameter_str(MIGRATION_PARAMETER_DSA_ACCEL_PATH)); + while (dsa_accel_path) { + monitor_printf(mon, " '%s'", dsa_accel_path->value); + dsa_accel_path = dsa_accel_path->next; + } + monitor_printf(mon, "\n"); + } if (params->has_block_bitmap_mapping) { const BitmapMigrationNodeAliasList *bmnal; @@ -563,6 +572,14 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) p->has_x_checkpoint_delay = true; visit_type_uint32(v, param, &p->x_checkpoint_delay, &err); break; + case MIGRATION_PARAMETER_DSA_ACCEL_PATH: + p->has_dsa_accel_path = true; + g_autofree char **strv = g_strsplit(valuestr ? : "", " ", -1); + strList **tail = &p->dsa_accel_path; + for (int i = 0; strv[i]; i++) { + QAPI_LIST_APPEND(tail, strv[i]); + } + break; case MIGRATION_PARAMETER_MULTIFD_CHANNELS: p->has_multifd_channels = true; visit_type_uint8(v, param, &p->multifd_channels, &err); diff --git a/migration/options.c b/migration/options.c index 147cd2b8fd..a0b3a7d291 100644 --- a/migration/options.c +++ b/migration/options.c @@ -13,6 +13,7 @@ #include "qemu/osdep.h" #include "qemu/error-report.h" +#include "qemu/dsa.h" #include "exec/target_page.h" #include "qapi/clone-visitor.h" #include "qapi/error.h" @@ -832,6 +833,13 @@ const char *migrate_tls_creds(void) return s->parameters.tls_creds; } +const strList *migrate_dsa_accel_path(void) +{ + MigrationState *s = migrate_get_current(); + + return s->parameters.dsa_accel_path; +} + const char *migrate_tls_hostname(void) { MigrationState *s = migrate_get_current(); @@ -945,6 +953,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) params->zero_page_detection = s->parameters.zero_page_detection; params->has_direct_io = true; params->direct_io = s->parameters.direct_io; + params->has_dsa_accel_path = true; + params->dsa_accel_path = QAPI_CLONE(strList, s->parameters.dsa_accel_path); return params; } @@ -953,6 +963,7 @@ void migrate_params_init(MigrationParameters *params) { params->tls_hostname = g_strdup(""); params->tls_creds = g_strdup(""); + params->dsa_accel_path = NULL; /* Set has_* up only for parameter checks */ params->has_throttle_trigger_threshold = true; @@ -1165,6 +1176,14 @@ bool migrate_params_check(MigrationParameters *params, Error **errp) return false; } + if (params->has_zero_page_detection && + params->zero_page_detection == ZERO_PAGE_DETECTION_DSA_ACCEL) { + if (!qemu_dsa_is_supported()) { + error_setg(errp, "DSA acceleration is not supported."); + return false; + } + } + return true; } @@ -1278,6 +1297,11 @@ static void migrate_params_test_apply(MigrateSetParameters *params, if (params->has_direct_io) { dest->direct_io = params->direct_io; } + + if (params->has_dsa_accel_path) { + dest->has_dsa_accel_path = true; + dest->dsa_accel_path = params->dsa_accel_path; + } } static void migrate_params_apply(MigrateSetParameters *params, Error **errp) @@ -1410,6 +1434,12 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) if (params->has_direct_io) { s->parameters.direct_io = params->direct_io; } + if (params->has_dsa_accel_path) { + qapi_free_strList(s->parameters.dsa_accel_path); + s->parameters.has_dsa_accel_path = true; + s->parameters.dsa_accel_path = + QAPI_CLONE(strList, params->dsa_accel_path); + } } void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp) diff --git a/migration/options.h b/migration/options.h index a0bd6edc06..8198b220bd 100644 --- a/migration/options.h +++ b/migration/options.h @@ -86,6 +86,7 @@ const char *migrate_tls_creds(void); const char *migrate_tls_hostname(void); uint64_t migrate_xbzrle_cache_size(void); ZeroPageDetection migrate_zero_page_detection(void); +const strList *migrate_dsa_accel_path(void); /* parameters helpers */ diff --git a/qapi/migration.json b/qapi/migration.json index b66cccf107..d8b42ceae6 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -626,10 +626,14 @@ # multifd migration is enabled, else in the main migration thread # as for @legacy. # +# @dsa-accel: Perform zero page checking with the DSA accelerator +# offloading in multifd sender thread if multifd migration is +# enabled, else in the main migration thread as for @legacy. +# # Since: 9.0 ## { 'enum': 'ZeroPageDetection', - 'data': [ 'none', 'legacy', 'multifd' ] } + 'data': [ 'none', 'legacy', 'multifd', 'dsa-accel' ] } ## # @BitmapMigrationBitmapAliasTransform: @@ -837,6 +841,12 @@ # See description in @ZeroPageDetection. Default is 'multifd'. # (since 9.0) # +# @dsa-accel-path: If enabled, use DSA accelerator offloading for +# certain memory operations. Enable DSA accelerator for zero +# page detection offloading by setting the @zero-page-detection +# to dsa-accel. This parameter defines the dsa device path, and +# defaults to an empty list. (Since 9.2) +# # @direct-io: Open migration files with O_DIRECT when possible. This # only has effect if the @mapped-ram capability is enabled. # (Since 9.1) @@ -855,7 +865,7 @@ 'cpu-throttle-initial', 'cpu-throttle-increment', 'cpu-throttle-tailslow', 'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth', - 'avail-switchover-bandwidth', 'downtime-limit', + 'avail-switchover-bandwidth', 'downtime-limit', 'dsa-accel-path', { 'name': 'x-checkpoint-delay', 'features': [ 'unstable' ] }, 'multifd-channels', 'xbzrle-cache-size', 'max-postcopy-bandwidth', @@ -1018,6 +1028,12 @@ # See description in @ZeroPageDetection. Default is 'multifd'. # (since 9.0) # +# @dsa-accel-path: If enabled, use DSA accelerator offloading for +# certain memory operations. Enable DSA accelerator for zero +# page detection offloading by setting the @zero-page-detection +# to dsa-accel. This parameter defines the dsa device path, and +# defaults to an empty list. (Since 9.2) +# # @direct-io: Open migration files with O_DIRECT when possible. This # only has effect if the @mapped-ram capability is enabled. # (Since 9.1) @@ -1063,7 +1079,8 @@ '*vcpu-dirty-limit': 'uint64', '*mode': 'MigMode', '*zero-page-detection': 'ZeroPageDetection', - '*direct-io': 'bool' } } + '*direct-io': 'bool', + '*dsa-accel-path': [ 'str' ] } } ## # @migrate-set-parameters: @@ -1228,6 +1245,12 @@ # See description in @ZeroPageDetection. Default is 'multifd'. # (since 9.0) # +# @dsa-accel-path: If enabled, use DSA accelerator offloading for +# certain memory operations. Enable DSA accelerator for zero +# page detection offloading by setting the @zero-page-detection +# to dsa-accel. This parameter defines the dsa device path, and +# defaults to an empty list. (Since 9.2) +# # @direct-io: Open migration files with O_DIRECT when possible. This # only has effect if the @mapped-ram capability is enabled. # (Since 9.1) @@ -1270,7 +1293,8 @@ '*vcpu-dirty-limit': 'uint64', '*mode': 'MigMode', '*zero-page-detection': 'ZeroPageDetection', - '*direct-io': 'bool' } } + '*direct-io': 'bool', + '*dsa-accel-path': [ 'str' ] } } ## # @query-migrate-parameters: diff --git a/util/dsa.c b/util/dsa.c index cbaa47c360..eeede3c0c7 100644 --- a/util/dsa.c +++ b/util/dsa.c @@ -23,6 +23,7 @@ #include "qemu/bswap.h" #include "qemu/error-report.h" #include "qemu/rcu.h" +#include <cpuid.h> #pragma GCC push_options #pragma GCC target("enqcmd") @@ -691,6 +692,36 @@ static void dsa_completion_thread_stop(void *opaque) qemu_sem_destroy(&thread_context->sem_init_done); } +/** + * @brief Check if DSA is supported. + * + * @return True if DSA is supported, otherwise false. + */ +bool qemu_dsa_is_supported(void) +{ + /* + * movdir64b is indicated by bit 28 of ecx in CPUID leaf 7, subleaf 0. + * enqcmd is indicated by bit 29 of ecx in CPUID leaf 7, subleaf 0. + * Doc: https://cdrdv2-public.intel.com/819680/architecture-instruction-\ + * set-extensions-programming-reference.pdf + */ + uint32_t eax, ebx, ecx, edx; + bool movedirb_enabled; + bool enqcmd_enabled; + + __get_cpuid_count(7, 0, &eax, &ebx, &ecx, &edx); + movedirb_enabled = (ecx >> 28) & 0x1; + if (!movedirb_enabled) { + return false; + } + enqcmd_enabled = (ecx >> 29) & 0x1; + if (!enqcmd_enabled) { + return false; + } + + return true; +} + /** * @brief Check if DSA is running. *