* Haozhong Zhang (haozhong.zh...@intel.com) wrote:
> When loading a xbzrle encoded page to persistent memory, load the data
> via libpmem function pmem_memcpy_nodrain() instead of memcpy().
> Combined with a call to pmem_drain() at the end of memory loading, we
> can guarantee those xbzrle encoded pages are persistently loaded to PMEM.
>
> Signed-off-by: Haozhong Zhang <haozhong.zh...@intel.com>
> ---
> migration/ram.c | 15 ++++++++++-----
> migration/xbzrle.c | 20 ++++++++++++++++++--
> migration/xbzrle.h | 1 +
> 3 files changed, 29 insertions(+), 7 deletions(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index 924d2b9537..87f977617d 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -2388,10 +2388,10 @@ static void ram_save_pending(QEMUFile *f, void
> *opaque, uint64_t max_size,
> }
> }
>
> -static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
> +static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host, bool
> is_pmem)
> {
> unsigned int xh_len;
> - int xh_flags;
> + int xh_flags, rc;
> uint8_t *loaded_data;
>
> /* extract RLE header */
> @@ -2413,8 +2413,13 @@ static int load_xbzrle(QEMUFile *f, ram_addr_t addr,
> void *host)
> qemu_get_buffer_in_place(f, &loaded_data, xh_len);
>
> /* decode RLE */
> - if (xbzrle_decode_buffer(loaded_data, xh_len, host,
> - TARGET_PAGE_SIZE) == -1) {
> + if (!is_pmem) {
> + rc = xbzrle_decode_buffer(loaded_data, xh_len, host,
> TARGET_PAGE_SIZE);
> + } else {
> + rc = xbzrle_decode_buffer_to_pmem(loaded_data, xh_len, host,
> + TARGET_PAGE_SIZE);
> + }
> + if (rc == -1) {
> error_report("Failed to load XBZRLE page - decode error!");
> return -1;
> }
> @@ -2974,7 +2979,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> break;
>
> case RAM_SAVE_FLAG_XBZRLE:
> - if (load_xbzrle(f, addr, host) < 0) {
> + if (load_xbzrle(f, addr, host, is_pmem) < 0) {
> error_report("Failed to decompress XBZRLE page at "
> RAM_ADDR_FMT, addr);
> ret = -EINVAL;
> diff --git a/migration/xbzrle.c b/migration/xbzrle.c
> index 1ba482ded9..499d8e1bfb 100644
> --- a/migration/xbzrle.c
> +++ b/migration/xbzrle.c
> @@ -12,6 +12,7 @@
> */
> #include "qemu/osdep.h"
> #include "qemu/cutils.h"
> +#include "qemu/pmem.h"
> #include "xbzrle.h"
>
> /*
> @@ -126,7 +127,8 @@ int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t
> *new_buf, int slen,
> return d;
> }
>
> -int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen)
> +static int xbzrle_decode_buffer_common(uint8_t *src, int slen, uint8_t *dst,
> + int dlen, bool is_pmem)
> {
> int i = 0, d = 0;
> int ret;
> @@ -167,10 +169,24 @@ int xbzrle_decode_buffer(uint8_t *src, int slen,
> uint8_t *dst, int dlen)
> return -1;
> }
>
> - memcpy(dst + d, src + i, count);
> + if (!is_pmem) {
> + memcpy(dst + d, src + i, count);
> + } else {
> + pmem_memcpy_nodrain(dst + d, src + i, count);
> + }
> d += count;
> i += count;
> }
>
> return d;
> }
> +
> +int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen)
> +{
> + return xbzrle_decode_buffer_common(src, slen, dst, dlen, false);
> +}
> +
> +int xbzrle_decode_buffer_to_pmem(uint8_t *src, int slen, uint8_t *dst, int
> dlen)
> +{
> + return xbzrle_decode_buffer_common(src, slen, dst, dlen, true);
> +}
Again I wouldn't bother with these two wrappers, just add the is_pmem
flag or pointer to xbzrle_decode_buffer. Note that in xbzrle load this
is doing lots of small copies; I'm not sure if this changes your needs.
Dave
> diff --git a/migration/xbzrle.h b/migration/xbzrle.h
> index a0db507b9c..ac5ae32666 100644
> --- a/migration/xbzrle.h
> +++ b/migration/xbzrle.h
> @@ -18,4 +18,5 @@ int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t
> *new_buf, int slen,
> uint8_t *dst, int dlen);
>
> int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
> +int xbzrle_decode_buffer_to_pmem(uint8_t *src, int slen, uint8_t *dst, int
> dlen);
> #endif
> --
> 2.14.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
