| Message ID | 20180207073331.14158-9-haozhong.zhang@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | nvdimm: guarantee persistence of QEMU writes to persistent memory | expand |
* Haozhong Zhang (haozhong.zhang@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.zhang@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 / dgilbert@redhat.com / Manchester, UK
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); +} 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
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.zhang@intel.com> --- migration/ram.c | 15 ++++++++++----- migration/xbzrle.c | 20 ++++++++++++++++++-- migration/xbzrle.h | 1 + 3 files changed, 29 insertions(+), 7 deletions(-)