* Alexey Perevalov (a.pereva...@samsung.com) wrote: > This patch adds ability to track down already received > pages, it's necessary for calculation vCPU block time in > postcopy migration feature, maybe for restore after > postcopy migration failure. > Also it's necessary to solve shared memory issue in > postcopy livemigration. Information about received pages > will be transferred to the software virtual bridge > (e.g. OVS-VSWITCHD), to avoid fallocate (unmap) for > already received pages. fallocate syscall is required for > remmaped shared memory, due to remmaping itself blocks > ioctl(UFFDIO_COPY, ioctl in this case will end with EEXIT > error (struct page is exists after remmap). > > Bitmap is placed into RAMBlock as another postcopy/precopy > related bitmaps. > > Signed-off-by: Alexey Perevalov <a.pereva...@samsung.com> > --- > include/exec/ram_addr.h | 3 +++ > migration/migration.c | 1 + > migration/postcopy-ram.c | 12 ++++++--- > migration/ram.c | 66 > +++++++++++++++++++++++++++++++++++++++++++++--- > migration/ram.h | 6 +++++ > 5 files changed, 82 insertions(+), 6 deletions(-) > > diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h > index 140efa8..67fbb39 100644 > --- a/include/exec/ram_addr.h > +++ b/include/exec/ram_addr.h > @@ -47,6 +47,8 @@ struct RAMBlock { > * of the postcopy phase > */ > unsigned long *unsentmap; > + /* bitmap of already received pages in postcopy */ > + unsigned long *receivedmap; > }; > > static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset) > @@ -60,6 +62,7 @@ static inline void *ramblock_ptr(RAMBlock *block, > ram_addr_t offset) > return (char *)block->host + offset; > } > > +unsigned long int ramblock_recv_bitmap_offset(void *host_addr, RAMBlock *rb); > long qemu_getrampagesize(void); > unsigned long last_ram_page(void); > RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, > diff --git a/migration/migration.c b/migration/migration.c > index 71e38bc..53fbd41 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -143,6 +143,7 @@ MigrationIncomingState > *migration_incoming_get_current(void) > qemu_mutex_init(&mis_current.rp_mutex); > qemu_event_init(&mis_current.main_thread_load_event, false); > once = true; > + ramblock_recv_map_init(); > } > return &mis_current; > } > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > index d1af2c1..5d2b92d 100644 > --- a/migration/postcopy-ram.c > +++ b/migration/postcopy-ram.c > @@ -562,8 +562,13 @@ int postcopy_ram_enable_notify(MigrationIncomingState > *mis) > } > > static int qemu_ufd_copy_ioctl(int userfault_fd, void *host_addr, > - void *from_addr, uint64_t pagesize) > + void *from_addr, uint64_t pagesize, RAMBlock *rb) > { > + /* received page isn't feature of blocktime calculation, > + * it's more general entity, so keep it here, > + * but gup betwean two following operation could be high, > + * and in this case blocktime for such small interval will be lost */ > + ramblock_recv_bitmap_set(host_addr, rb);
I have a fun problem here in my world with using the same bitmap for shared memory with the vhost-user client; for that a set bit means that the data has already arrived and we need to do a UFFDIO_WAKE on the client; but that means we can't set the bit in this function until the end after we've done the COPY/ZERO. Dave > if (from_addr) { > struct uffdio_copy copy_struct; > copy_struct.dst = (uint64_t)(uintptr_t)host_addr; > @@ -594,7 +599,7 @@ int postcopy_place_page(MigrationIncomingState *mis, void > *host, void *from, > * which would be slightly cheaper, but we'd have to be careful > * of the order of updating our page state. > */ > - if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, from, pagesize)) { > + if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, from, pagesize, rb)) { > int e = errno; > error_report("%s: %s copy host: %p from: %p (size: %zd)", > __func__, strerror(e), host, from, pagesize); > @@ -616,7 +621,8 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, > void *host, > trace_postcopy_place_page_zero(host); > > if (qemu_ram_pagesize(rb) == getpagesize()) { > - if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, 0, getpagesize())) { > + if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, 0, getpagesize(), > + rb)) { > int e = errno; > error_report("%s: %s zero host: %p", > __func__, strerror(e), host); > diff --git a/migration/ram.c b/migration/ram.c > index f50479d..fad4dbf 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -151,6 +151,41 @@ out: > return ret; > } > > +void ramblock_recv_map_init(void) > +{ > + RAMBlock *rb; > + > + RAMBLOCK_FOREACH(rb) { > + unsigned long pages; > + pages = rb->max_length >> TARGET_PAGE_BITS; > + assert(!rb->receivedmap); > + rb->receivedmap = bitmap_new(pages); > + } > +} > + > +unsigned long int ramblock_recv_bitmap_offset(void *host_addr, RAMBlock *rb) > +{ > + uint64_t host_addr_offset = (uint64_t)(uintptr_t)(host_addr > + - (void *)rb->host); > + return host_addr_offset >> TARGET_PAGE_BITS; > +} > + > +int ramblock_recv_bitmap_test(void *host_addr, RAMBlock *rb) > +{ > + return test_bit(ramblock_recv_bitmap_offset(host_addr, rb), > + rb->receivedmap); > +} > + > +void ramblock_recv_bitmap_set(void *host_addr, RAMBlock *rb) > +{ > + set_bit_atomic(ramblock_recv_bitmap_offset(host_addr, rb), > rb->receivedmap); > +} > + > +void ramblock_recv_bitmap_clear(void *host_addr, RAMBlock *rb) > +{ > + clear_bit(ramblock_recv_bitmap_offset(host_addr, rb), rb->receivedmap); > +} > + > /* > * An outstanding page request, on the source, having been received > * and queued > @@ -1773,6 +1808,18 @@ int ram_postcopy_send_discard_bitmap(MigrationState > *ms) > return ret; > } > > +static void ramblock_recv_bitmap_clear_range(uint64_t start, size_t length, > + RAMBlock *rb) > +{ > + int i, range_count; > + range_count = length >> TARGET_PAGE_BITS; > + for (i = 0; i < range_count; i++) { > + ramblock_recv_bitmap_clear((void *)((uint64_t)(intptr_t)rb->host + > + start), rb); > + start += TARGET_PAGE_SIZE; > + } > +} > + > /** > * ram_discard_range: discard dirtied pages at the beginning of postcopy > * > @@ -1797,6 +1844,7 @@ int ram_discard_range(const char *rbname, uint64_t > start, size_t length) > goto err; > } > > + ramblock_recv_bitmap_clear_range(start, length, rb); > ret = ram_block_discard_range(rb, start, length); > > err: > @@ -2324,8 +2372,14 @@ static int ram_load_setup(QEMUFile *f, void *opaque) > > static int ram_load_cleanup(void *opaque) > { > + RAMBlock *rb; > xbzrle_load_cleanup(); > compress_threads_load_cleanup(); > + > + RAMBLOCK_FOREACH(rb) { > + g_free(rb->receivedmap); > + rb->receivedmap = NULL; > + } > return 0; > } > > @@ -2513,6 +2567,7 @@ static int ram_load(QEMUFile *f, void *opaque, int > version_id) > ram_addr_t addr, total_ram_bytes; > void *host = NULL; > uint8_t ch; > + RAMBlock *rb; > > addr = qemu_get_be64(f); > flags = addr & ~TARGET_PAGE_MASK; > @@ -2520,15 +2575,15 @@ static int ram_load(QEMUFile *f, void *opaque, int > version_id) > > if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE | > RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) { > - RAMBlock *block = ram_block_from_stream(f, flags); > + rb = ram_block_from_stream(f, flags); > > - host = host_from_ram_block_offset(block, addr); > + host = host_from_ram_block_offset(rb, addr); > if (!host) { > error_report("Illegal RAM offset " RAM_ADDR_FMT, addr); > ret = -EINVAL; > break; > } > - trace_ram_load_loop(block->idstr, (uint64_t)addr, flags, host); > + trace_ram_load_loop(rb->idstr, (uint64_t)addr, flags, host); > } > > switch (flags & ~RAM_SAVE_FLAG_CONTINUE) { > @@ -2582,10 +2637,12 @@ static int ram_load(QEMUFile *f, void *opaque, int > version_id) > > case RAM_SAVE_FLAG_ZERO: > ch = qemu_get_byte(f); > + ramblock_recv_bitmap_set(host, rb); > ram_handle_compressed(host, ch, TARGET_PAGE_SIZE); > break; > > case RAM_SAVE_FLAG_PAGE: > + ramblock_recv_bitmap_set(host, rb); > qemu_get_buffer(f, host, TARGET_PAGE_SIZE); > break; > > @@ -2596,10 +2653,13 @@ static int ram_load(QEMUFile *f, void *opaque, int > version_id) > ret = -EINVAL; > break; > } > + > + ramblock_recv_bitmap_set(host, rb); > decompress_data_with_multi_threads(f, host, len); > break; > > case RAM_SAVE_FLAG_XBZRLE: > + ramblock_recv_bitmap_set(host, rb); > if (load_xbzrle(f, addr, host) < 0) { > error_report("Failed to decompress XBZRLE page at " > RAM_ADDR_FMT, addr); > diff --git a/migration/ram.h b/migration/ram.h > index c081fde..98d68df 100644 > --- a/migration/ram.h > +++ b/migration/ram.h > @@ -52,4 +52,10 @@ int ram_discard_range(const char *block_name, uint64_t > start, size_t length); > int ram_postcopy_incoming_init(MigrationIncomingState *mis); > > void ram_handle_compressed(void *host, uint8_t ch, uint64_t size); > + > +void ramblock_recv_map_init(void); > +int ramblock_recv_bitmap_test(void *host_addr, RAMBlock *rb); > +void ramblock_recv_bitmap_set(void *host_addr, RAMBlock *rb); > +void ramblock_recv_bitmap_clear(void *host_addr, RAMBlock *rb); > + > #endif > -- > 1.8.3.1 > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK