* 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 | 10 ++++++++
> migration/migration.c | 1 +
> migration/postcopy-ram.c | 20 ++++++++++++----
> migration/ram.c | 59
> +++++++++++++++++++++++++++++++++++++++++++++---
> migration/ram.h | 6 +++++
> 5 files changed, 88 insertions(+), 8 deletions(-)
>
> diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
> index 140efa8..4170656 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 +62,14 @@ static inline void *ramblock_ptr(RAMBlock *block,
> ram_addr_t offset)
> return (char *)block->host + offset;
> }
>
> +static inline 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;
> +}
> +
> 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 293db97..372c691 100644
> --- a/migration/postcopy-ram.c
> +++ b/migration/postcopy-ram.c
> @@ -562,22 +562,31 @@ 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)
> {
> + int ret;
> if (from_addr) {
> struct uffdio_copy copy_struct;
> copy_struct.dst = (uint64_t)(uintptr_t)host_addr;
> copy_struct.src = (uint64_t)(uintptr_t)from_addr;
> copy_struct.len = pagesize;
> copy_struct.mode = 0;
> - return ioctl(userfault_fd, UFFDIO_COPY, ©_struct);
> + ret = ioctl(userfault_fd, UFFDIO_COPY, ©_struct);
> } else {
> struct uffdio_zeropage zero_struct;
> zero_struct.range.start = (uint64_t)(uintptr_t)host_addr;
> zero_struct.range.len = pagesize;
> zero_struct.mode = 0;
> - return ioctl(userfault_fd, UFFDIO_ZEROPAGE, &zero_struct);
> + ret = ioctl(userfault_fd, UFFDIO_ZEROPAGE, &zero_struct);
> + }
> + /* 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 */
> + if (!ret) {
> + ramblock_recv_bitmap_set(host_addr, rb);
> }
> + return ret;
> }
>
> /*
> @@ -594,7 +603,7 @@ 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 +625,8 @@ 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, NULL,
> getpagesize())) {
> + if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, NULL, 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..37299ed 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -151,6 +151,34 @@ 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);
> + }
> +}
> +
> +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 +1801,18 @@ 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;
> + long nr_bit = start >> TARGET_PAGE_BITS;
> + range_count = length >> TARGET_PAGE_BITS;
> + for (i = 0; i < range_count; i++) {
> + clear_bit(nr_bit, rb->receivedmap);
> + nr_bit += 1;
> + }
Can you just use the bitmap_clear(map,start,nr) function in bitmap.h for
that loop?
The rest looks OK (although I'd bet we probably need something special
for RDMA, but that's normal for RDMA).
Dave
> +}
> +
> /**
> * ram_discard_range: discard dirtied pages at the beginning of postcopy
> *
> @@ -1797,6 +1837,7 @@ 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 +2365,14 @@ 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 +2560,7 @@ 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 = NULL;
>
> addr = qemu_get_be64(f);
> flags = addr & ~TARGET_PAGE_MASK;
> @@ -2520,15 +2568,15 @@ 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 +2630,12 @@ 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 +2646,13 @@ 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
> --
> 1.9.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
