From 33af2fc0d1fd87e26c9ed15a3ce07a61cbbaa490 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Fri, 7 Nov 2014 17:18:00 +0100 Subject: [PATCH 13/41] dump: add APIs to operate DataCache Message-id: <1415380693-16593-14-git-send-email-lersek@redhat.com> Patchwork-id: 62199 O-Subject: [RHEL-7.1 qemu-kvm PATCH 13/26] dump: add APIs to operate DataCache Bugzilla: 1157798 RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Luiz Capitulino RH-Acked-by: dgibson From: qiaonuohan DataCache is used to store data temporarily, then the data will be written to vmcore. These functions will be called later when writing data of page to vmcore. Signed-off-by: Qiao Nuohan Reviewed-by: Laszlo Ersek Signed-off-by: Luiz Capitulino (cherry picked from commit 64cfba6a47411092c941c8d17256fb5673cc8cbf) Signed-off-by: Laszlo Ersek Signed-off-by: Miroslav Rezanina --- dump.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ include/sysemu/dump.h | 9 +++++++++ 2 files changed, 56 insertions(+) diff --git a/dump.c b/dump.c index f416093..926ab84 100644 --- a/dump.c +++ b/dump.c @@ -1171,6 +1171,53 @@ out: return ret; } +static void prepare_data_cache(DataCache *data_cache, DumpState *s, + off_t offset) +{ + data_cache->fd = s->fd; + data_cache->data_size = 0; + data_cache->buf_size = BUFSIZE_DATA_CACHE; + data_cache->buf = g_malloc0(BUFSIZE_DATA_CACHE); + data_cache->offset = offset; +} + +static int write_cache(DataCache *dc, const void *buf, size_t size, + bool flag_sync) +{ + /* + * dc->buf_size should not be less than size, otherwise dc will never be + * enough + */ + assert(size <= dc->buf_size); + + /* + * if flag_sync is set, synchronize data in dc->buf into vmcore. + * otherwise check if the space is enough for caching data in buf, if not, + * write the data in dc->buf to dc->fd and reset dc->buf + */ + if ((!flag_sync && dc->data_size + size > dc->buf_size) || + (flag_sync && dc->data_size > 0)) { + if (write_buffer(dc->fd, dc->offset, dc->buf, dc->data_size) < 0) { + return -1; + } + + dc->offset += dc->data_size; + dc->data_size = 0; + } + + if (!flag_sync) { + memcpy(dc->buf + dc->data_size, buf, size); + dc->data_size += size; + } + + return 0; +} + +static void free_data_cache(DataCache *data_cache) +{ + g_free(data_cache->buf); +} + static ram_addr_t get_start_block(DumpState *s) { GuestPhysBlock *block; diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h index 6d4d0bc..92a95e4 100644 --- a/include/sysemu/dump.h +++ b/include/sysemu/dump.h @@ -41,6 +41,7 @@ #define DISKDUMP_HEADER_BLOCKS (1) #define BUFSIZE_BITMAP (TARGET_PAGE_SIZE) #define PFN_BUFBITMAP (CHAR_BIT * BUFSIZE_BITMAP) +#define BUFSIZE_DATA_CACHE (TARGET_PAGE_SIZE * 4) typedef struct ArchDumpInfo { int d_machine; /* Architecture */ @@ -142,6 +143,14 @@ typedef struct QEMU_PACKED KdumpSubHeader64 { uint64_t max_mapnr_64; /* header_version 6 and later */ } KdumpSubHeader64; +typedef struct DataCache { + int fd; /* fd of the file where to write the cached data */ + uint8_t *buf; /* buffer for cached data */ + size_t buf_size; /* size of the buf */ + size_t data_size; /* size of cached data in buf */ + off_t offset; /* offset of the file */ +} DataCache; + struct GuestPhysBlockList; /* memory_mapping.h */ int cpu_get_dump_info(ArchDumpInfo *info, const struct GuestPhysBlockList *guest_phys_blocks); -- 1.8.3.1