From c6ef839d84726cf420a0381174f0f8ffac6ffd84 Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Wed, 17 Jun 2015 12:08:38 +0100 Subject: [PATCH] libxl: refactor toolstack save restore code This patch does following things: 1. Document v1 format. 2. Factor out function to handle QEMU restore data and function to handle v1 blob for restore path. 3. Refactor save function to generate different blobs in the order specified in format specification. 4. Change functions to use "goto out" idiom. No functional changes introduced. Signed-off-by: Wei Liu Acked-by: Ian Campbell --- tools/libxl/libxl_dom.c | 232 ++++++++++++++++++++++++---------------- 1 file changed, 142 insertions(+), 90 deletions(-) diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c index 867172a5ef..600393df4e 100644 --- a/tools/libxl/libxl_dom.c +++ b/tools/libxl/libxl_dom.c @@ -1032,6 +1032,15 @@ struct libxl__physmap_info { char name[]; }; +/* Bump version every time when toolstack saved data changes. + * Different types of data are arranged in the specified order. + * + * Version 1: + * uint32_t version + * QEMU physmap data: + * uint32_t count + * libxl__physmap_info * count + */ #define TOOLSTACK_SAVE_VERSION 1 static inline char *restore_helper(libxl__gc *gc, uint32_t dm_domid, @@ -1043,41 +1052,28 @@ static inline char *restore_helper(libxl__gc *gc, uint32_t dm_domid, phys_offset, node); } -int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf, - uint32_t size, void *user) +static int libxl__toolstack_restore_qemu(libxl__gc *gc, uint32_t domid, + const uint8_t *ptr, uint32_t size) { - libxl__save_helper_state *shs = user; - libxl__domain_create_state *dcs = CONTAINER_OF(shs, *dcs, shs); - STATE_AO_GC(dcs->ao); - int i, ret; - const uint8_t *ptr = buf; - uint32_t count = 0, version = 0; - struct libxl__physmap_info* pi; + int ret, i; + uint32_t count; char *xs_path; uint32_t dm_domid; + struct libxl__physmap_info *pi; - LOG(DEBUG,"domain=%"PRIu32" toolstack data size=%"PRIu32, domid, size); - - if (size < sizeof(version) + sizeof(count)) { + if (size < sizeof(count)) { LOG(ERROR, "wrong size"); - return -1; - } - - memcpy(&version, ptr, sizeof(version)); - ptr += sizeof(version); - - if (version != TOOLSTACK_SAVE_VERSION) { - LOG(ERROR, "wrong version"); - return -1; + ret = -1; + goto out; } memcpy(&count, ptr, sizeof(count)); ptr += sizeof(count); - if (size < sizeof(version) + sizeof(count) + - count * (sizeof(struct libxl__physmap_info))) { + if (size < sizeof(count) + count*(sizeof(struct libxl__physmap_info))) { LOG(ERROR, "wrong size"); - return -1; + ret = -1; + goto out; } dm_domid = libxl_get_stubdom_id(CTX, domid); @@ -1088,21 +1084,64 @@ int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf, xs_path = restore_helper(gc, dm_domid, domid, pi->phys_offset, "start_addr"); ret = libxl__xs_write(gc, 0, xs_path, "%"PRIx64, pi->start_addr); - if (ret) - return -1; + if (ret) goto out; + xs_path = restore_helper(gc, dm_domid, domid, pi->phys_offset, "size"); ret = libxl__xs_write(gc, 0, xs_path, "%"PRIx64, pi->size); - if (ret) - return -1; + if (ret) goto out; + if (pi->namelen > 0) { xs_path = restore_helper(gc, dm_domid, domid, pi->phys_offset, "name"); ret = libxl__xs_write(gc, 0, xs_path, "%s", pi->name); - if (ret) - return -1; + if (ret) goto out; } } - return 0; + + ret = 0; +out: + return ret; + +} + +static int libxl__toolstack_restore_v1(libxl__gc *gc, uint32_t domid, + const uint8_t *ptr, uint32_t size) +{ + return libxl__toolstack_restore_qemu(gc, domid, ptr, size); +} + +int libxl__toolstack_restore(uint32_t domid, const uint8_t *ptr, + uint32_t size, void *user) +{ + libxl__save_helper_state *shs = user; + libxl__domain_create_state *dcs = CONTAINER_OF(shs, *dcs, shs); + STATE_AO_GC(dcs->ao); + int ret; + uint32_t version = 0, bufsize; + + LOG(DEBUG,"domain=%"PRIu32" toolstack data size=%"PRIu32, domid, size); + + if (size < sizeof(version)) { + LOG(ERROR, "wrong size"); + ret = -1; + goto out; + } + + memcpy(&version, ptr, sizeof(version)); + ptr += sizeof(version); + bufsize = size - sizeof(version); + + switch (version) { + case 1: + ret = libxl__toolstack_restore_v1(gc, domid, ptr, bufsize); + break; + default: + LOG(ERROR, "wrong version"); + ret = -1; + } + +out: + return ret; } /*==================== Domain suspend (save) ====================*/ @@ -1685,81 +1724,94 @@ int libxl__toolstack_save(uint32_t domid, uint8_t **buf, uint32_t *len, void *dss_void) { libxl__domain_suspend_state *dss = dss_void; + int ret; STATE_AO_GC(dss->ao); int i = 0; - char *start_addr = NULL, *size = NULL, *phys_offset = NULL, *name = NULL; - unsigned int num = 0; - uint32_t count = 0, version = TOOLSTACK_SAVE_VERSION, namelen = 0; + uint32_t version = TOOLSTACK_SAVE_VERSION; uint8_t *ptr = NULL; - char **entries = NULL; - struct libxl__physmap_info *pi; - uint32_t dm_domid; - dm_domid = libxl_get_stubdom_id(CTX, domid); + ret = -1; - entries = libxl__xs_directory(gc, 0, - libxl__device_model_xs_path(gc, dm_domid, domid, "/physmap"), - &num); - count = num; - - *len = sizeof(version) + sizeof(count); + /* Version number */ + *len = sizeof(version); *buf = calloc(1, *len); + if (*buf == NULL) goto out; ptr = *buf; - if (*buf == NULL) - return -1; - memcpy(ptr, &version, sizeof(version)); - ptr += sizeof(version); - memcpy(ptr, &count, sizeof(count)); - ptr += sizeof(count); - for (i = 0; i < count; i++) { - unsigned long offset; - char *xs_path; - phys_offset = entries[i]; - if (phys_offset == NULL) { - LOG(ERROR, "phys_offset %d is NULL", i); - return -1; - } + /* QEMU physmap data */ + { + char **entries = NULL, *xs_path; + struct libxl__physmap_info *pi; + uint32_t dm_domid; + char *start_addr = NULL, *size = NULL, *phys_offset = NULL; + char *name = NULL; + unsigned int num = 0; + uint32_t count = 0, namelen = 0; + + dm_domid = libxl_get_stubdom_id(CTX, domid); + + xs_path = libxl__device_model_xs_path(gc, dm_domid, domid, + "/physmap"); + entries = libxl__xs_directory(gc, 0, xs_path, &num); + count = num; + + *len += sizeof(count); + *buf = realloc(*buf, *len); + if (*buf == NULL) goto out; + ptr = *buf + sizeof(version); + memcpy(ptr, &count, sizeof(count)); + ptr += sizeof(count); + + for (i = 0; i < count; i++) { + unsigned long offset; + phys_offset = entries[i]; + if (phys_offset == NULL) { + LOG(ERROR, "phys_offset %d is NULL", i); + goto out; + } - xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "start_addr"); - start_addr = libxl__xs_read(gc, 0, xs_path); - if (start_addr == NULL) { - LOG(ERROR, "%s is NULL", xs_path); - return -1; - } + xs_path = physmap_path(gc, dm_domid, domid, phys_offset, + "start_addr"); + start_addr = libxl__xs_read(gc, 0, xs_path); + if (start_addr == NULL) { + LOG(ERROR, "%s is NULL", xs_path); + goto out; + } - xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "size"); - size = libxl__xs_read(gc, 0, xs_path); - if (size == NULL) { - LOG(ERROR, "%s is NULL", xs_path); - return -1; - } + xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "size"); + size = libxl__xs_read(gc, 0, xs_path); + if (size == NULL) { + LOG(ERROR, "%s is NULL", xs_path); + goto out; + } - xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "name"); - name = libxl__xs_read(gc, 0, xs_path); - if (name == NULL) - namelen = 0; - else - namelen = strlen(name) + 1; - *len += namelen + sizeof(struct libxl__physmap_info); - offset = ptr - (*buf); - *buf = realloc(*buf, *len); - if (*buf == NULL) - return -1; - ptr = (*buf) + offset; - pi = (struct libxl__physmap_info *) ptr; - pi->phys_offset = strtoll(phys_offset, NULL, 16); - pi->start_addr = strtoll(start_addr, NULL, 16); - pi->size = strtoll(size, NULL, 16); - pi->namelen = namelen; - memcpy(pi->name, name, namelen); - ptr += sizeof(struct libxl__physmap_info) + namelen; + xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "name"); + name = libxl__xs_read(gc, 0, xs_path); + if (name == NULL) + namelen = 0; + else + namelen = strlen(name) + 1; + *len += namelen + sizeof(struct libxl__physmap_info); + offset = ptr - (*buf); + *buf = realloc(*buf, *len); + if (*buf == NULL) goto out; + ptr = (*buf) + offset; + pi = (struct libxl__physmap_info *) ptr; + pi->phys_offset = strtoll(phys_offset, NULL, 16); + pi->start_addr = strtoll(start_addr, NULL, 16); + pi->size = strtoll(size, NULL, 16); + pi->namelen = namelen; + memcpy(pi->name, name, namelen); + ptr += sizeof(struct libxl__physmap_info) + namelen; + } } LOG(DEBUG,"domain=%"PRIu32" toolstack data size=%"PRIu32, domid, *len); - return 0; + ret = 0; +out: + return ret; } static void libxl__domain_suspend_callback(void *data) -- 2.30.2