From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Wolfgang Bumiller Date: Mon, 4 May 2020 11:05:08 +0200 Subject: [PATCH] PVE: add optional buffer size to QEMUFile So we can use a 4M buffer for savevm-async which should increase performance storing the state onto ceph. Signed-off-by: Wolfgang Bumiller [increase max IOV count in QEMUFile to actually write more data] Signed-off-by: Stefan Reiter --- migration/qemu-file.c | 38 +++++++++++++++++++++++++------------- migration/qemu-file.h | 1 + migration/savevm-async.c | 4 ++-- 3 files changed, 28 insertions(+), 15 deletions(-) diff --git a/migration/qemu-file.c b/migration/qemu-file.c index be21518c57..1926b5202c 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -30,8 +30,8 @@ #include "trace.h" #include "qapi/error.h" -#define IO_BUF_SIZE 32768 -#define MAX_IOV_SIZE MIN_CONST(IOV_MAX, 64) +#define DEFAULT_IO_BUF_SIZE 32768 +#define MAX_IOV_SIZE MIN_CONST(IOV_MAX, 256) struct QEMUFile { const QEMUFileOps *ops; @@ -45,7 +45,8 @@ struct QEMUFile { when reading */ int buf_index; int buf_size; /* 0 when writing */ - uint8_t buf[IO_BUF_SIZE]; + size_t buf_allocated_size; + uint8_t *buf; DECLARE_BITMAP(may_free, MAX_IOV_SIZE); struct iovec iov[MAX_IOV_SIZE]; @@ -101,7 +102,7 @@ bool qemu_file_mode_is_not_valid(const char *mode) return false; } -QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops) +QEMUFile *qemu_fopen_ops_sized(void *opaque, const QEMUFileOps *ops, size_t buffer_size) { QEMUFile *f; @@ -109,9 +110,17 @@ QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops) f->opaque = opaque; f->ops = ops; + f->buf_allocated_size = buffer_size; + f->buf = malloc(buffer_size); + return f; } +QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops) +{ + return qemu_fopen_ops_sized(opaque, ops, DEFAULT_IO_BUF_SIZE); +} + void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks) { @@ -346,7 +355,7 @@ static ssize_t qemu_fill_buffer(QEMUFile *f) } len = f->ops->get_buffer(f->opaque, f->buf + pending, f->pos, - IO_BUF_SIZE - pending, &local_error); + f->buf_allocated_size - pending, &local_error); if (len > 0) { f->buf_size += len; f->pos += len; @@ -386,6 +395,9 @@ int qemu_fclose(QEMUFile *f) ret = ret2; } } + + free(f->buf); + /* If any error was spotted before closing, we should report it * instead of the close() return value. */ @@ -435,7 +447,7 @@ static void add_buf_to_iovec(QEMUFile *f, size_t len) { if (!add_to_iovec(f, f->buf + f->buf_index, len, false)) { f->buf_index += len; - if (f->buf_index == IO_BUF_SIZE) { + if (f->buf_index == f->buf_allocated_size) { qemu_fflush(f); } } @@ -461,7 +473,7 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size) } while (size > 0) { - l = IO_BUF_SIZE - f->buf_index; + l = f->buf_allocated_size - f->buf_index; if (l > size) { l = size; } @@ -508,8 +520,8 @@ size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset) size_t index; assert(!qemu_file_is_writable(f)); - assert(offset < IO_BUF_SIZE); - assert(size <= IO_BUF_SIZE - offset); + assert(offset < f->buf_allocated_size); + assert(size <= f->buf_allocated_size - offset); /* The 1st byte to read from */ index = f->buf_index + offset; @@ -559,7 +571,7 @@ size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size) size_t res; uint8_t *src; - res = qemu_peek_buffer(f, &src, MIN(pending, IO_BUF_SIZE), 0); + res = qemu_peek_buffer(f, &src, MIN(pending, f->buf_allocated_size), 0); if (res == 0) { return done; } @@ -593,7 +605,7 @@ size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size) */ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size) { - if (size < IO_BUF_SIZE) { + if (size < f->buf_allocated_size) { size_t res; uint8_t *src; @@ -618,7 +630,7 @@ int qemu_peek_byte(QEMUFile *f, int offset) int index = f->buf_index + offset; assert(!qemu_file_is_writable(f)); - assert(offset < IO_BUF_SIZE); + assert(offset < f->buf_allocated_size); if (index >= f->buf_size) { qemu_fill_buffer(f); @@ -770,7 +782,7 @@ static int qemu_compress_data(z_stream *stream, uint8_t *dest, size_t dest_len, ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream, const uint8_t *p, size_t size) { - ssize_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t); + ssize_t blen = f->buf_allocated_size - f->buf_index - sizeof(int32_t); if (blen < compressBound(size)) { return -1; diff --git a/migration/qemu-file.h b/migration/qemu-file.h index a9b6d6ccb7..8752d27c74 100644 --- a/migration/qemu-file.h +++ b/migration/qemu-file.h @@ -120,6 +120,7 @@ typedef struct QEMUFileHooks { } QEMUFileHooks; QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops); +QEMUFile *qemu_fopen_ops_sized(void *opaque, const QEMUFileOps *ops, size_t buffer_size); void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks); int qemu_get_fd(QEMUFile *f); int qemu_fclose(QEMUFile *f); diff --git a/migration/savevm-async.c b/migration/savevm-async.c index 4e345c1a7d..8a17ec1f74 100644 --- a/migration/savevm-async.c +++ b/migration/savevm-async.c @@ -414,7 +414,7 @@ void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp) goto restart; } - snap_state.file = qemu_fopen_ops(&snap_state, &block_file_ops); + snap_state.file = qemu_fopen_ops_sized(&snap_state, &block_file_ops, 4 * 1024 * 1024); if (!snap_state.file) { error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile); @@ -563,7 +563,7 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp) blk_op_block_all(be, blocker); /* restore the VM state */ - f = qemu_fopen_ops(be, &loadstate_file_ops); + f = qemu_fopen_ops_sized(be, &loadstate_file_ops, 4 * 1024 * 1024); if (!f) { error_setg(errp, "Could not open VM state file"); goto the_end;