| Message ID | 20240425022117.4035031-11-hao.xiang@linux.dev |
|---|---|
| State | New |
| Headers | show |
| Series | Use Intel DSA accelerator to offload zero page checking in multifd live migration. | expand |
On Thu, Apr 25, 2024 at 02:21:13AM +0000, Hao Xiang wrote: > Multifd sender path gets an array of pages queued by the migration > thread. It performs zero page checking on every page in the array. > The pages are classfied as either a zero page or a normal page. This > change uses Intel DSA to offload the zero page checking from CPU to > the DSA accelerator. The sender thread submits a batch of pages to DSA > hardware and waits for the DSA completion thread to signal for work > completion. > > Signed-off-by: Hao Xiang <hao.xiang@linux.dev> > --- > migration/multifd-zero-page.c | 99 +++++++++++++++++++++++++++++++++-- > migration/multifd.c | 27 +++++++++- > migration/multifd.h | 1 + > 3 files changed, 120 insertions(+), 7 deletions(-) > > diff --git a/migration/multifd-zero-page.c b/migration/multifd-zero-page.c > index e1b8370f88..4f426289e4 100644 > --- a/migration/multifd-zero-page.c > +++ b/migration/multifd-zero-page.c > diff --git a/migration/multifd.c b/migration/multifd.c > index cfd3a92f6c..7316643d0a 100644 > --- a/migration/multifd.c > +++ b/migration/multifd.c > @@ -818,6 +818,8 @@ void multifd_send_shutdown(void) > > multifd_send_terminate_threads(); > > + dsa_cleanup(); > + > for (i = 0; i < migrate_multifd_channels(); i++) { > MultiFDSendParams *p = &multifd_send_state->params[i]; > Error *local_err = NULL; > @@ -1155,11 +1157,20 @@ bool multifd_send_setup(void) > uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); > bool use_packets = multifd_use_packets(); > uint8_t i; > + const char *dsa_parameter = migrate_multifd_dsa_accel(); > > if (!migrate_multifd()) { > return true; > } > > + if (dsa_init(dsa_parameter)) { > + error_setg(&local_err, "multifd: Sender failed to initialize DSA."); > + error_report_err(local_err); > + return false; > + } This is an example of why all the dsa functions need to report a via an "Error **err" parameter. The error reported here is useless as it lacks any meaningful information of what went wrong. The multifd_send_setup method itself needs a "Error **errp" param so it can pass it back up to be reoprted too. > + > + dsa_start(); > + > thread_count = migrate_multifd_channels(); > multifd_send_state = g_malloc0(sizeof(*multifd_send_state)); > multifd_send_state->params = g_new0(MultiFDSendParams, thread_count); > @@ -1393,6 +1404,7 @@ void multifd_recv_cleanup(void) > qemu_thread_join(&p->thread); > } > } > + dsa_cleanup(); > for (i = 0; i < migrate_multifd_channels(); i++) { > multifd_recv_cleanup_channel(&multifd_recv_state->params[i]); > } > @@ -1568,6 +1580,9 @@ int multifd_recv_setup(Error **errp) > uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); > bool use_packets = multifd_use_packets(); > uint8_t i; > + const char *dsa_parameter = migrate_multifd_dsa_accel(); > + int ret; > + Error *local_err = NULL; > > /* > * Return successfully if multiFD recv state is already initialised > @@ -1577,6 +1592,15 @@ int multifd_recv_setup(Error **errp) > return 0; > } > > + ret = dsa_init(dsa_parameter); > + if (ret != 0) { > + error_setg(&local_err, "multifd: Receiver failed to initialize DSA."); > + error_propagate(errp, local_err); > + return ret; > + } > + > + dsa_start(); > + > thread_count = migrate_multifd_channels(); > multifd_recv_state = g_malloc0(sizeof(*multifd_recv_state)); > multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count); > @@ -1616,13 +1640,12 @@ int multifd_recv_setup(Error **errp) > > for (i = 0; i < thread_count; i++) { > MultiFDRecvParams *p = &multifd_recv_state->params[i]; > - int ret; > - > ret = multifd_recv_state->ops->recv_setup(p, errp); > if (ret) { > return ret; > } > } > + > return 0; > } > > diff --git a/migration/multifd.h b/migration/multifd.h > index 16e27db5e9..b3717fae24 100644 > --- a/migration/multifd.h > +++ b/migration/multifd.h > @@ -14,6 +14,7 @@ > #define QEMU_MIGRATION_MULTIFD_H > > #include "ram.h" > +#include "qemu/dsa.h" > > typedef struct MultiFDRecvData MultiFDRecvData; > > -- > 2.30.2 > > With regards, Daniel
Hao Xiang <hao.xiang@linux.dev> writes: > Multifd sender path gets an array of pages queued by the migration > thread. It performs zero page checking on every page in the array. > The pages are classfied as either a zero page or a normal page. This > change uses Intel DSA to offload the zero page checking from CPU to > the DSA accelerator. The sender thread submits a batch of pages to DSA > hardware and waits for the DSA completion thread to signal for work > completion. > > Signed-off-by: Hao Xiang <hao.xiang@linux.dev> > --- > migration/multifd-zero-page.c | 99 +++++++++++++++++++++++++++++++++-- > migration/multifd.c | 27 +++++++++- > migration/multifd.h | 1 + > 3 files changed, 120 insertions(+), 7 deletions(-) > > diff --git a/migration/multifd-zero-page.c b/migration/multifd-zero-page.c > index e1b8370f88..4f426289e4 100644 > --- a/migration/multifd-zero-page.c > +++ b/migration/multifd-zero-page.c > @@ -37,25 +37,83 @@ static void swap_page_offset(ram_addr_t *pages_offset, int a, int b) > } > > /** > - * multifd_send_zero_page_detect: Perform zero page detection on all pages. > + * zero_page_detect_cpu: Perform zero page detection using CPU. > * > * Sorts normal pages before zero pages in p->pages->offset and updates > * p->pages->normal_num. > * > * @param p A pointer to the send params. > */ > -void multifd_send_zero_page_detect(MultiFDSendParams *p) > +static void zero_page_detect_cpu(MultiFDSendParams *p) > { > MultiFDPages_t *pages = p->pages; > RAMBlock *rb = pages->block; > int i = 0; > int j = pages->num - 1; > > - if (!multifd_zero_page_enabled()) { > - pages->normal_num = pages->num; > + /* > + * Sort the page offset array by moving all normal pages to > + * the left and all zero pages to the right of the array. > + */ > + while (i <= j) { > + uint64_t offset = pages->offset[i]; > + > + if (!buffer_is_zero(rb->host + offset, p->page_size)) { > + i++; > + continue; > + } > + > + swap_page_offset(pages->offset, i, j); > + ram_release_page(rb->idstr, offset); > + j--; > + } > + > + pages->normal_num = i; > +} > + > + > +#ifdef CONFIG_DSA_OPT > + > +static void swap_result(bool *results, int a, int b) > +{ > + bool temp; > + > + if (a == b) { > return; > } > > + temp = results[a]; > + results[a] = results[b]; > + results[b] = temp; > +} > + > +/** > + * zero_page_detect_dsa: Perform zero page detection using > + * Intel Data Streaming Accelerator (DSA). > + * > + * Sorts normal pages before zero pages in p->pages->offset and updates > + * p->pages->normal_num. > + * > + * @param p A pointer to the send params. > + */ > +static void zero_page_detect_dsa(MultiFDSendParams *p) > +{ > + MultiFDPages_t *pages = p->pages; > + RAMBlock *rb = pages->block; > + bool *results = p->batch_task->results; At this point I don't see the need to carry p->batch_task in the multifd code. results here could be taken from the buffer_is_zero_dsa_batch_async call below. > + > + for (int i = 0; i < p->pages->num; i++) { > + p->batch_task->addr[i] = (ram_addr_t)(rb->host + p->pages->offset[i]); ... and this is just what p->iov[0].iov_base contains. > + } > + > + buffer_is_zero_dsa_batch_async(p->batch_task, This is not async. You're using the result right after this call. Leave the 'async' for the functions called from whithin this one, which do the actual wait part. > + (const void **)p->batch_task->addr, > + p->pages->num, > + p->page_size); > + > + int i = 0; > + int j = pages->num - 1; > + > /* > * Sort the page offset array by moving all normal pages to > * the left and all zero pages to the right of the array. > @@ -63,11 +121,12 @@ void multifd_send_zero_page_detect(MultiFDSendParams *p) > while (i <= j) { > uint64_t offset = pages->offset[i]; > > - if (!buffer_is_zero(rb->host + offset, p->page_size)) { > + if (!results[i]) { > i++; > continue; > } > > + swap_result(results, i, j); > swap_page_offset(pages->offset, i, j); > ram_release_page(rb->idstr, offset); > j--; > @@ -76,6 +135,15 @@ void multifd_send_zero_page_detect(MultiFDSendParams *p) > pages->normal_num = i; > } > > +#else > + > +static void zero_page_detect_dsa(MultiFDSendParams *p) > +{ > + exit(1); > +} > + > +#endif > + > void multifd_recv_zero_page_process(MultiFDRecvParams *p) > { > for (int i = 0; i < p->zero_num; i++) { > @@ -87,3 +155,24 @@ void multifd_recv_zero_page_process(MultiFDRecvParams *p) > } > } > } > + > +/** > + * multifd_send_zero_page_detect: Perform zero page detection on all pages. > + * > + * @param p A pointer to the send params. > + */ > +void multifd_send_zero_page_detect(MultiFDSendParams *p) > +{ > + MultiFDPages_t *pages = p->pages; > + > + if (!multifd_zero_page_enabled()) { > + pages->normal_num = pages->num; > + return; > + } > + > + if (dsa_is_running()) { > + zero_page_detect_dsa(p); > + } else { > + zero_page_detect_cpu(p); > + } > +} > diff --git a/migration/multifd.c b/migration/multifd.c > index cfd3a92f6c..7316643d0a 100644 > --- a/migration/multifd.c > +++ b/migration/multifd.c > @@ -818,6 +818,8 @@ void multifd_send_shutdown(void) > > multifd_send_terminate_threads(); > > + dsa_cleanup(); > + > for (i = 0; i < migrate_multifd_channels(); i++) { > MultiFDSendParams *p = &multifd_send_state->params[i]; > Error *local_err = NULL; > @@ -1155,11 +1157,20 @@ bool multifd_send_setup(void) > uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); > bool use_packets = multifd_use_packets(); > uint8_t i; > + const char *dsa_parameter = migrate_multifd_dsa_accel(); > > if (!migrate_multifd()) { > return true; > } > > + if (dsa_init(dsa_parameter)) { > + error_setg(&local_err, "multifd: Sender failed to initialize DSA."); > + error_report_err(local_err); > + return false; > + } > + > + dsa_start(); > + > thread_count = migrate_multifd_channels(); > multifd_send_state = g_malloc0(sizeof(*multifd_send_state)); > multifd_send_state->params = g_new0(MultiFDSendParams, thread_count); > @@ -1393,6 +1404,7 @@ void multifd_recv_cleanup(void) > qemu_thread_join(&p->thread); > } > } > + dsa_cleanup(); > for (i = 0; i < migrate_multifd_channels(); i++) { > multifd_recv_cleanup_channel(&multifd_recv_state->params[i]); > } > @@ -1568,6 +1580,9 @@ int multifd_recv_setup(Error **errp) > uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); > bool use_packets = multifd_use_packets(); > uint8_t i; > + const char *dsa_parameter = migrate_multifd_dsa_accel(); > + int ret; > + Error *local_err = NULL; > > /* > * Return successfully if multiFD recv state is already initialised > @@ -1577,6 +1592,15 @@ int multifd_recv_setup(Error **errp) > return 0; > } > > + ret = dsa_init(dsa_parameter); > + if (ret != 0) { > + error_setg(&local_err, "multifd: Receiver failed to initialize DSA."); > + error_propagate(errp, local_err); > + return ret; > + } > + > + dsa_start(); > + > thread_count = migrate_multifd_channels(); > multifd_recv_state = g_malloc0(sizeof(*multifd_recv_state)); > multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count); > @@ -1616,13 +1640,12 @@ int multifd_recv_setup(Error **errp) > > for (i = 0; i < thread_count; i++) { > MultiFDRecvParams *p = &multifd_recv_state->params[i]; > - int ret; > - > ret = multifd_recv_state->ops->recv_setup(p, errp); > if (ret) { > return ret; > } > } > + > return 0; > } > > diff --git a/migration/multifd.h b/migration/multifd.h > index 16e27db5e9..b3717fae24 100644 > --- a/migration/multifd.h > +++ b/migration/multifd.h > @@ -14,6 +14,7 @@ > #define QEMU_MIGRATION_MULTIFD_H > > #include "ram.h" > +#include "qemu/dsa.h" > > typedef struct MultiFDRecvData MultiFDRecvData;
On Thu, Apr 25, 2024 at 02:21:13AM +0000, Hao Xiang wrote: > Multifd sender path gets an array of pages queued by the migration > thread. It performs zero page checking on every page in the array. > The pages are classfied as either a zero page or a normal page. This > change uses Intel DSA to offload the zero page checking from CPU to > the DSA accelerator. The sender thread submits a batch of pages to DSA > hardware and waits for the DSA completion thread to signal for work > completion. > > Signed-off-by: Hao Xiang <hao.xiang@linux.dev> > --- > migration/multifd-zero-page.c | 99 +++++++++++++++++++++++++++++++++-- > migration/multifd.c | 27 +++++++++- > migration/multifd.h | 1 + > 3 files changed, 120 insertions(+), 7 deletions(-) > > diff --git a/migration/multifd-zero-page.c b/migration/multifd-zero-page.c > index e1b8370f88..4f426289e4 100644 > --- a/migration/multifd-zero-page.c > +++ b/migration/multifd-zero-page.c > @@ -37,25 +37,83 @@ static void swap_page_offset(ram_addr_t *pages_offset, int a, int b) > } > > /** > - * multifd_send_zero_page_detect: Perform zero page detection on all pages. > + * zero_page_detect_cpu: Perform zero page detection using CPU. > * > * Sorts normal pages before zero pages in p->pages->offset and updates > * p->pages->normal_num. > * > * @param p A pointer to the send params. > */ > -void multifd_send_zero_page_detect(MultiFDSendParams *p) > +static void zero_page_detect_cpu(MultiFDSendParams *p) > { > MultiFDPages_t *pages = p->pages; > RAMBlock *rb = pages->block; > int i = 0; > int j = pages->num - 1; > > - if (!multifd_zero_page_enabled()) { > - pages->normal_num = pages->num; > + /* > + * Sort the page offset array by moving all normal pages to > + * the left and all zero pages to the right of the array. > + */ > + while (i <= j) { > + uint64_t offset = pages->offset[i]; > + > + if (!buffer_is_zero(rb->host + offset, p->page_size)) { > + i++; > + continue; > + } > + > + swap_page_offset(pages->offset, i, j); > + ram_release_page(rb->idstr, offset); > + j--; > + } > + > + pages->normal_num = i; > +} > + > + > +#ifdef CONFIG_DSA_OPT > + > +static void swap_result(bool *results, int a, int b) > +{ > + bool temp; > + > + if (a == b) { > return; > } > > + temp = results[a]; > + results[a] = results[b]; > + results[b] = temp; > +} > + > +/** > + * zero_page_detect_dsa: Perform zero page detection using > + * Intel Data Streaming Accelerator (DSA). > + * > + * Sorts normal pages before zero pages in p->pages->offset and updates > + * p->pages->normal_num. > + * > + * @param p A pointer to the send params. > + */ > +static void zero_page_detect_dsa(MultiFDSendParams *p) > +{ > + MultiFDPages_t *pages = p->pages; > + RAMBlock *rb = pages->block; > + bool *results = p->batch_task->results; > + > + for (int i = 0; i < p->pages->num; i++) { > + p->batch_task->addr[i] = (ram_addr_t)(rb->host + p->pages->offset[i]); > + } > + > + buffer_is_zero_dsa_batch_async(p->batch_task, > + (const void **)p->batch_task->addr, > + p->pages->num, > + p->page_size); > + > + int i = 0; > + int j = pages->num - 1; > + > /* > * Sort the page offset array by moving all normal pages to > * the left and all zero pages to the right of the array. > @@ -63,11 +121,12 @@ void multifd_send_zero_page_detect(MultiFDSendParams *p) > while (i <= j) { > uint64_t offset = pages->offset[i]; > > - if (!buffer_is_zero(rb->host + offset, p->page_size)) { > + if (!results[i]) { > i++; > continue; > } > > + swap_result(results, i, j); > swap_page_offset(pages->offset, i, j); > ram_release_page(rb->idstr, offset); > j--; > @@ -76,6 +135,15 @@ void multifd_send_zero_page_detect(MultiFDSendParams *p) > pages->normal_num = i; > } > > +#else > + > +static void zero_page_detect_dsa(MultiFDSendParams *p) > +{ > + exit(1); > +} > + > +#endif > + > void multifd_recv_zero_page_process(MultiFDRecvParams *p) > { > for (int i = 0; i < p->zero_num; i++) { > @@ -87,3 +155,24 @@ void multifd_recv_zero_page_process(MultiFDRecvParams *p) > } > } > } > + > +/** > + * multifd_send_zero_page_detect: Perform zero page detection on all pages. > + * > + * @param p A pointer to the send params. > + */ > +void multifd_send_zero_page_detect(MultiFDSendParams *p) > +{ > + MultiFDPages_t *pages = p->pages; > + > + if (!multifd_zero_page_enabled()) { > + pages->normal_num = pages->num; > + return; > + } > + > + if (dsa_is_running()) { > + zero_page_detect_dsa(p); > + } else { > + zero_page_detect_cpu(p); > + } > +} > diff --git a/migration/multifd.c b/migration/multifd.c > index cfd3a92f6c..7316643d0a 100644 > --- a/migration/multifd.c > +++ b/migration/multifd.c > @@ -818,6 +818,8 @@ void multifd_send_shutdown(void) > > multifd_send_terminate_threads(); > > + dsa_cleanup(); > + > for (i = 0; i < migrate_multifd_channels(); i++) { > MultiFDSendParams *p = &multifd_send_state->params[i]; > Error *local_err = NULL; > @@ -1155,11 +1157,20 @@ bool multifd_send_setup(void) > uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); > bool use_packets = multifd_use_packets(); > uint8_t i; > + const char *dsa_parameter = migrate_multifd_dsa_accel(); > > if (!migrate_multifd()) { > return true; > } > > + if (dsa_init(dsa_parameter)) { > + error_setg(&local_err, "multifd: Sender failed to initialize DSA."); > + error_report_err(local_err); > + return false; > + } > + > + dsa_start(); Commented on this in another reply, let's condense them into a single dsa call. That call should also be nested into a flag to know at least dsa is enabled: if (multifd_dsa_enabled()) { multifd_dsa_init(); } Multifd used to have some legacy code where it randomly call multifd_* functions directly in generic migration code. Not a good example to follow there.. Also, I'd think it better if we don't introduce global vars for dsa, it should be put under multifd_send_state (or recv_state). So anything like dsa_start() should always take that pointer first. > + > thread_count = migrate_multifd_channels(); > multifd_send_state = g_malloc0(sizeof(*multifd_send_state)); > multifd_send_state->params = g_new0(MultiFDSendParams, thread_count); > @@ -1393,6 +1404,7 @@ void multifd_recv_cleanup(void) > qemu_thread_join(&p->thread); > } > } > + dsa_cleanup(); Same here. > for (i = 0; i < migrate_multifd_channels(); i++) { > multifd_recv_cleanup_channel(&multifd_recv_state->params[i]); > } > @@ -1568,6 +1580,9 @@ int multifd_recv_setup(Error **errp) > uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); > bool use_packets = multifd_use_packets(); > uint8_t i; > + const char *dsa_parameter = migrate_multifd_dsa_accel(); > + int ret; > + Error *local_err = NULL; > > /* > * Return successfully if multiFD recv state is already initialised > @@ -1577,6 +1592,15 @@ int multifd_recv_setup(Error **errp) > return 0; > } > > + ret = dsa_init(dsa_parameter); > + if (ret != 0) { > + error_setg(&local_err, "multifd: Receiver failed to initialize DSA."); > + error_propagate(errp, local_err); > + return ret; > + } > + > + dsa_start(); Same here. in the dsa case, it'll be even better if you can find a way to unify send/recv, as IIUC they do work similarly, setup() some dsa stuff, do some zero page detection, cleanup() some dsa stuff. They look all the same irrelevant of src/dst. I think it's nice if we can merge them. > + > thread_count = migrate_multifd_channels(); > multifd_recv_state = g_malloc0(sizeof(*multifd_recv_state)); > multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count); > @@ -1616,13 +1640,12 @@ int multifd_recv_setup(Error **errp) > > for (i = 0; i < thread_count; i++) { > MultiFDRecvParams *p = &multifd_recv_state->params[i]; > - int ret; > - > ret = multifd_recv_state->ops->recv_setup(p, errp); > if (ret) { > return ret; > } > } > + > return 0; > } > > diff --git a/migration/multifd.h b/migration/multifd.h > index 16e27db5e9..b3717fae24 100644 > --- a/migration/multifd.h > +++ b/migration/multifd.h > @@ -14,6 +14,7 @@ > #define QEMU_MIGRATION_MULTIFD_H > > #include "ram.h" > +#include "qemu/dsa.h" > > typedef struct MultiFDRecvData MultiFDRecvData; > > -- > 2.30.2 > >
diff --git a/migration/multifd-zero-page.c b/migration/multifd-zero-page.c index e1b8370f88..4f426289e4 100644 --- a/migration/multifd-zero-page.c +++ b/migration/multifd-zero-page.c @@ -37,25 +37,83 @@ static void swap_page_offset(ram_addr_t *pages_offset, int a, int b) } /** - * multifd_send_zero_page_detect: Perform zero page detection on all pages. + * zero_page_detect_cpu: Perform zero page detection using CPU. * * Sorts normal pages before zero pages in p->pages->offset and updates * p->pages->normal_num. * * @param p A pointer to the send params. */ -void multifd_send_zero_page_detect(MultiFDSendParams *p) +static void zero_page_detect_cpu(MultiFDSendParams *p) { MultiFDPages_t *pages = p->pages; RAMBlock *rb = pages->block; int i = 0; int j = pages->num - 1; - if (!multifd_zero_page_enabled()) { - pages->normal_num = pages->num; + /* + * Sort the page offset array by moving all normal pages to + * the left and all zero pages to the right of the array. + */ + while (i <= j) { + uint64_t offset = pages->offset[i]; + + if (!buffer_is_zero(rb->host + offset, p->page_size)) { + i++; + continue; + } + + swap_page_offset(pages->offset, i, j); + ram_release_page(rb->idstr, offset); + j--; + } + + pages->normal_num = i; +} + + +#ifdef CONFIG_DSA_OPT + +static void swap_result(bool *results, int a, int b) +{ + bool temp; + + if (a == b) { return; } + temp = results[a]; + results[a] = results[b]; + results[b] = temp; +} + +/** + * zero_page_detect_dsa: Perform zero page detection using + * Intel Data Streaming Accelerator (DSA). + * + * Sorts normal pages before zero pages in p->pages->offset and updates + * p->pages->normal_num. + * + * @param p A pointer to the send params. + */ +static void zero_page_detect_dsa(MultiFDSendParams *p) +{ + MultiFDPages_t *pages = p->pages; + RAMBlock *rb = pages->block; + bool *results = p->batch_task->results; + + for (int i = 0; i < p->pages->num; i++) { + p->batch_task->addr[i] = (ram_addr_t)(rb->host + p->pages->offset[i]); + } + + buffer_is_zero_dsa_batch_async(p->batch_task, + (const void **)p->batch_task->addr, + p->pages->num, + p->page_size); + + int i = 0; + int j = pages->num - 1; + /* * Sort the page offset array by moving all normal pages to * the left and all zero pages to the right of the array. @@ -63,11 +121,12 @@ void multifd_send_zero_page_detect(MultiFDSendParams *p) while (i <= j) { uint64_t offset = pages->offset[i]; - if (!buffer_is_zero(rb->host + offset, p->page_size)) { + if (!results[i]) { i++; continue; } + swap_result(results, i, j); swap_page_offset(pages->offset, i, j); ram_release_page(rb->idstr, offset); j--; @@ -76,6 +135,15 @@ void multifd_send_zero_page_detect(MultiFDSendParams *p) pages->normal_num = i; } +#else + +static void zero_page_detect_dsa(MultiFDSendParams *p) +{ + exit(1); +} + +#endif + void multifd_recv_zero_page_process(MultiFDRecvParams *p) { for (int i = 0; i < p->zero_num; i++) { @@ -87,3 +155,24 @@ void multifd_recv_zero_page_process(MultiFDRecvParams *p) } } } + +/** + * multifd_send_zero_page_detect: Perform zero page detection on all pages. + * + * @param p A pointer to the send params. + */ +void multifd_send_zero_page_detect(MultiFDSendParams *p) +{ + MultiFDPages_t *pages = p->pages; + + if (!multifd_zero_page_enabled()) { + pages->normal_num = pages->num; + return; + } + + if (dsa_is_running()) { + zero_page_detect_dsa(p); + } else { + zero_page_detect_cpu(p); + } +} diff --git a/migration/multifd.c b/migration/multifd.c index cfd3a92f6c..7316643d0a 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -818,6 +818,8 @@ void multifd_send_shutdown(void) multifd_send_terminate_threads(); + dsa_cleanup(); + for (i = 0; i < migrate_multifd_channels(); i++) { MultiFDSendParams *p = &multifd_send_state->params[i]; Error *local_err = NULL; @@ -1155,11 +1157,20 @@ bool multifd_send_setup(void) uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); bool use_packets = multifd_use_packets(); uint8_t i; + const char *dsa_parameter = migrate_multifd_dsa_accel(); if (!migrate_multifd()) { return true; } + if (dsa_init(dsa_parameter)) { + error_setg(&local_err, "multifd: Sender failed to initialize DSA."); + error_report_err(local_err); + return false; + } + + dsa_start(); + thread_count = migrate_multifd_channels(); multifd_send_state = g_malloc0(sizeof(*multifd_send_state)); multifd_send_state->params = g_new0(MultiFDSendParams, thread_count); @@ -1393,6 +1404,7 @@ void multifd_recv_cleanup(void) qemu_thread_join(&p->thread); } } + dsa_cleanup(); for (i = 0; i < migrate_multifd_channels(); i++) { multifd_recv_cleanup_channel(&multifd_recv_state->params[i]); } @@ -1568,6 +1580,9 @@ int multifd_recv_setup(Error **errp) uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); bool use_packets = multifd_use_packets(); uint8_t i; + const char *dsa_parameter = migrate_multifd_dsa_accel(); + int ret; + Error *local_err = NULL; /* * Return successfully if multiFD recv state is already initialised @@ -1577,6 +1592,15 @@ int multifd_recv_setup(Error **errp) return 0; } + ret = dsa_init(dsa_parameter); + if (ret != 0) { + error_setg(&local_err, "multifd: Receiver failed to initialize DSA."); + error_propagate(errp, local_err); + return ret; + } + + dsa_start(); + thread_count = migrate_multifd_channels(); multifd_recv_state = g_malloc0(sizeof(*multifd_recv_state)); multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count); @@ -1616,13 +1640,12 @@ int multifd_recv_setup(Error **errp) for (i = 0; i < thread_count; i++) { MultiFDRecvParams *p = &multifd_recv_state->params[i]; - int ret; - ret = multifd_recv_state->ops->recv_setup(p, errp); if (ret) { return ret; } } + return 0; } diff --git a/migration/multifd.h b/migration/multifd.h index 16e27db5e9..b3717fae24 100644 --- a/migration/multifd.h +++ b/migration/multifd.h @@ -14,6 +14,7 @@ #define QEMU_MIGRATION_MULTIFD_H #include "ram.h" +#include "qemu/dsa.h" typedef struct MultiFDRecvData MultiFDRecvData;
Multifd sender path gets an array of pages queued by the migration thread. It performs zero page checking on every page in the array. The pages are classfied as either a zero page or a normal page. This change uses Intel DSA to offload the zero page checking from CPU to the DSA accelerator. The sender thread submits a batch of pages to DSA hardware and waits for the DSA completion thread to signal for work completion. Signed-off-by: Hao Xiang <hao.xiang@linux.dev> --- migration/multifd-zero-page.c | 99 +++++++++++++++++++++++++++++++++-- migration/multifd.c | 27 +++++++++- migration/multifd.h | 1 + 3 files changed, 120 insertions(+), 7 deletions(-)