From 33af2fc0d1fd87e26c9ed15a3ce07a61cbbaa490 Mon Sep 17 00:00:00 2001

From: Laszlo Ersek <lersek@redhat.com>

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 <stefanha@redhat.com>

RH-Acked-by: Luiz Capitulino <lcapitulino@redhat.com>

RH-Acked-by: dgibson <dgibson@redhat.com>

From: qiaonuohan <qiaonuohan@cn.fujitsu.com>

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 <qiaonuohan@cn.fujitsu.com>

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

(cherry picked from commit 64cfba6a47411092c941c8d17256fb5673cc8cbf)

Signed-off-by: Laszlo Ersek <lersek@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 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