| Message ID | 1576246112-23406-2-git-send-email-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | colo: fix return without releasing RCU | expand |
On 12/13/2019 11:03 PM, Dr. David Alan Gilbert wrote: > * Paolo Bonzini (pbonzini@redhat.com) wrote: >> Use WITH_RCU_READ_LOCK_GUARD to avoid exiting colo_init_ram_cache >> without releasing RCU. >> >> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Zhang Chen <chen.zhang@intel.com> > >> --- >> migration/ram.c | 33 +++++++++++++++++---------------- >> 1 file changed, 17 insertions(+), 16 deletions(-) >> >> diff --git a/migration/ram.c b/migration/ram.c >> index 7dd7f81..8d7c015 100644 >> --- a/migration/ram.c >> +++ b/migration/ram.c >> @@ -3891,26 +3891,27 @@ int colo_init_ram_cache(void) >> { >> RAMBlock *block; >> >> - rcu_read_lock(); >> - RAMBLOCK_FOREACH_NOT_IGNORED(block) { >> - block->colo_cache = qemu_anon_ram_alloc(block->used_length, >> - NULL, >> - false); >> - if (!block->colo_cache) { >> - error_report("%s: Can't alloc memory for COLO cache of block %s," >> - "size 0x" RAM_ADDR_FMT, __func__, block->idstr, >> - block->used_length); >> - RAMBLOCK_FOREACH_NOT_IGNORED(block) { >> - if (block->colo_cache) { >> - qemu_anon_ram_free(block->colo_cache, block->used_length); >> - block->colo_cache = NULL; >> + WITH_RCU_READ_LOCK_GUARD() { >> + RAMBLOCK_FOREACH_NOT_IGNORED(block) { >> + block->colo_cache = qemu_anon_ram_alloc(block->used_length, >> + NULL, >> + false); >> + if (!block->colo_cache) { >> + error_report("%s: Can't alloc memory for COLO cache of block %s," >> + "size 0x" RAM_ADDR_FMT, __func__, block->idstr, >> + block->used_length); >> + RAMBLOCK_FOREACH_NOT_IGNORED(block) { >> + if (block->colo_cache) { >> + qemu_anon_ram_free(block->colo_cache, block->used_length); >> + block->colo_cache = NULL; >> + } >> } >> + return -errno; >> } >> - return -errno; >> + memcpy(block->colo_cache, block->host, block->used_length); >> } >> - memcpy(block->colo_cache, block->host, block->used_length); >> } >> - rcu_read_unlock(); >> + >> /* >> * Record the dirty pages that sent by PVM, we use this dirty bitmap together >> * with to decide which page in cache should be flushed into SVM's RAM. Here >> -- >> 1.8.3.1 >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >
diff --git a/migration/ram.c b/migration/ram.c index 7dd7f81..8d7c015 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3891,26 +3891,27 @@ int colo_init_ram_cache(void) { RAMBlock *block; - rcu_read_lock(); - RAMBLOCK_FOREACH_NOT_IGNORED(block) { - block->colo_cache = qemu_anon_ram_alloc(block->used_length, - NULL, - false); - if (!block->colo_cache) { - error_report("%s: Can't alloc memory for COLO cache of block %s," - "size 0x" RAM_ADDR_FMT, __func__, block->idstr, - block->used_length); - RAMBLOCK_FOREACH_NOT_IGNORED(block) { - if (block->colo_cache) { - qemu_anon_ram_free(block->colo_cache, block->used_length); - block->colo_cache = NULL; + WITH_RCU_READ_LOCK_GUARD() { + RAMBLOCK_FOREACH_NOT_IGNORED(block) { + block->colo_cache = qemu_anon_ram_alloc(block->used_length, + NULL, + false); + if (!block->colo_cache) { + error_report("%s: Can't alloc memory for COLO cache of block %s," + "size 0x" RAM_ADDR_FMT, __func__, block->idstr, + block->used_length); + RAMBLOCK_FOREACH_NOT_IGNORED(block) { + if (block->colo_cache) { + qemu_anon_ram_free(block->colo_cache, block->used_length); + block->colo_cache = NULL; + } } + return -errno; } - return -errno; + memcpy(block->colo_cache, block->host, block->used_length); } - memcpy(block->colo_cache, block->host, block->used_length); } - rcu_read_unlock(); + /* * Record the dirty pages that sent by PVM, we use this dirty bitmap together * with to decide which page in cache should be flushed into SVM's RAM. Here
Use WITH_RCU_READ_LOCK_GUARD to avoid exiting colo_init_ram_cache without releasing RCU. Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- migration/ram.c | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-)