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author | Michael S. Tsirkin <mst@redhat.com> | 2010-11-22 19:52:34 +0200 |
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committer | Michael S. Tsirkin <mst@redhat.com> | 2010-12-02 21:13:39 +0200 |
commit | b2e0a138e77245290428a7d599a929e2e1bfe510 (patch) | |
tree | 5c483ccf4927fbdd9a1000695a36658574d8f542 | |
parent | c924f36a300cbc54d3cb511116e8e2bae17f5ae6 (diff) | |
download | qemu-b2e0a138e77245290428a7d599a929e2e1bfe510.zip qemu-b2e0a138e77245290428a7d599a929e2e1bfe510.tar.gz qemu-b2e0a138e77245290428a7d599a929e2e1bfe510.tar.bz2 |
migration: stable ram block ordering
This makes ram block ordering under migration stable, ordered by offset.
This is especially useful for migration to exec, for debugging.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Jason Wang <jasowang@redhat.com>
-rw-r--r-- | arch_init.c | 35 | ||||
-rw-r--r-- | cpu-common.h | 3 | ||||
-rw-r--r-- | exec.c | 24 | ||||
-rw-r--r-- | kvm-all.c | 2 |
4 files changed, 61 insertions, 3 deletions
diff --git a/arch_init.c b/arch_init.c index 4486925..e32e289 100644 --- a/arch_init.c +++ b/arch_init.c @@ -23,6 +23,7 @@ */ #include <stdint.h> #include <stdarg.h> +#include <stdlib.h> #ifndef _WIN32 #include <sys/types.h> #include <sys/mman.h> @@ -212,6 +213,39 @@ uint64_t ram_bytes_total(void) return total; } +static int block_compar(const void *a, const void *b) +{ + RAMBlock * const *ablock = a; + RAMBlock * const *bblock = b; + if ((*ablock)->offset < (*bblock)->offset) { + return -1; + } else if ((*ablock)->offset > (*bblock)->offset) { + return 1; + } + return 0; +} + +static void sort_ram_list(void) +{ + RAMBlock *block, *nblock, **blocks; + int n; + n = 0; + QLIST_FOREACH(block, &ram_list.blocks, next) { + ++n; + } + blocks = qemu_malloc(n * sizeof *blocks); + n = 0; + QLIST_FOREACH_SAFE(block, &ram_list.blocks, next, nblock) { + blocks[n++] = block; + QLIST_REMOVE(block, next); + } + qsort(blocks, n, sizeof *blocks, block_compar); + while (--n >= 0) { + QLIST_INSERT_HEAD(&ram_list.blocks, blocks[n], next); + } + qemu_free(blocks); +} + int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque) { ram_addr_t addr; @@ -234,6 +268,7 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque) bytes_transferred = 0; last_block = NULL; last_offset = 0; + sort_ram_list(); /* Make sure all dirty bits are set */ QLIST_FOREACH(block, &ram_list.blocks, next) { diff --git a/cpu-common.h b/cpu-common.h index a543b5d..bb6b137 100644 --- a/cpu-common.h +++ b/cpu-common.h @@ -46,6 +46,9 @@ ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size); void qemu_ram_free(ram_addr_t addr); /* This should only be used for ram local to a device. */ void *qemu_get_ram_ptr(ram_addr_t addr); +/* Same but slower, to use for migration, where the order of + * RAMBlocks must not change. */ +void *qemu_safe_ram_ptr(ram_addr_t addr); /* This should not be used by devices. */ int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr); ram_addr_t qemu_ram_addr_from_host_nofail(void *ptr); @@ -2030,10 +2030,10 @@ void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end, /* we modify the TLB cache so that the dirty bit will be set again when accessing the range */ - start1 = (unsigned long)qemu_get_ram_ptr(start); + start1 = (unsigned long)qemu_safe_ram_ptr(start); /* Chek that we don't span multiple blocks - this breaks the address comparisons below. */ - if ((unsigned long)qemu_get_ram_ptr(end - 1) - start1 + if ((unsigned long)qemu_safe_ram_ptr(end - 1) - start1 != (end - 1) - start) { abort(); } @@ -2858,6 +2858,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, new_block->length = size; QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next); + fprintf(stderr, "alloc ram %s len 0x%x\n", new_block->idstr, (int)new_block->length); ram_list.phys_dirty = qemu_realloc(ram_list.phys_dirty, last_ram_offset() >> TARGET_PAGE_BITS); @@ -2931,6 +2932,25 @@ void *qemu_get_ram_ptr(ram_addr_t addr) return NULL; } +/* Return a host pointer to ram allocated with qemu_ram_alloc. + * Same as qemu_get_ram_ptr but avoid reordering ramblocks. + */ +void *qemu_safe_ram_ptr(ram_addr_t addr) +{ + RAMBlock *block; + + QLIST_FOREACH(block, &ram_list.blocks, next) { + if (addr - block->offset < block->length) { + return block->host + (addr - block->offset); + } + } + + fprintf(stderr, "Bad ram offset %" PRIx64 "\n", (uint64_t)addr); + abort(); + + return NULL; +} + int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr) { RAMBlock *block; @@ -162,7 +162,7 @@ static int kvm_set_user_memory_region(KVMState *s, KVMSlot *slot) mem.slot = slot->slot; mem.guest_phys_addr = slot->start_addr; mem.memory_size = slot->memory_size; - mem.userspace_addr = (unsigned long)qemu_get_ram_ptr(slot->phys_offset); + mem.userspace_addr = (unsigned long)qemu_safe_ram_ptr(slot->phys_offset); mem.flags = slot->flags; if (s->migration_log) { mem.flags |= KVM_MEM_LOG_DIRTY_PAGES; |