The RAM save/restore code needs the RAMBlock in RAMBlockNotifier callbacks to decide whether migration must be aborted and to update RAMBlock state for postcopy. Looking up the RAMBlock inside callbacks is hazardous: with Xen mapcache it can deadlock, and it also leaves the callback contract unclear.
Pass the RAMBlock explicitly to RAMBlockNotifier callbacks. The ram_block_resized callback takes a non-const RAMBlock because it may modify the RAMBlock, while the other callbacks take const RAMBlock. Xen mapcache passes NULL because mapcache entries do not have a one-to-one relationship with RAMBlocks. ram_block_resized() is never called from Xen mapcache, so its RAMBlock argument is always non-NULL. Drop redundant parameters from ram_block_resized() because they can be derived from the RAMBlock. Keep them for the other callbacks because their RAMBlock argument may be NULL. Signed-off-by: Akihiko Odaki <[email protected]> --- include/system/ramlist.h | 18 ++++++++++-------- block/block-ram-registrar.c | 8 ++++---- hw/core/numa.c | 18 ++++++++++-------- hw/xen/xen-mapcache.c | 6 +++--- migration/ram.c | 12 +++--------- system/physmem.c | 7 +++---- target/i386/nvmm/nvmm-all.c | 4 ++-- target/i386/sev.c | 8 ++++---- util/vfio-helpers.c | 7 ++++--- 9 files changed, 43 insertions(+), 45 deletions(-) diff --git a/include/system/ramlist.h b/include/system/ramlist.h index c7f388f487d7..32157cc84305 100644 --- a/include/system/ramlist.h +++ b/include/system/ramlist.h @@ -62,11 +62,11 @@ void qemu_mutex_lock_ramlist(void); void qemu_mutex_unlock_ramlist(void); struct RAMBlockNotifier { - void (*ram_block_added)(RAMBlockNotifier *n, void *host, size_t size, - size_t max_size); - void (*ram_block_removed)(RAMBlockNotifier *n, void *host, size_t size, - size_t max_size); - void (*ram_block_resized)(RAMBlockNotifier *n, void *host, size_t old_size, + void (*ram_block_added)(RAMBlockNotifier *n, const RAMBlock *rb, + void *host, size_t size, size_t max_size); + void (*ram_block_removed)(RAMBlockNotifier *n, const RAMBlock *rb, + void *host, size_t size, size_t max_size); + void (*ram_block_resized)(RAMBlockNotifier *n, RAMBlock *rb, size_t new_size); QLIST_ENTRY(RAMBlockNotifier) next; }; @@ -77,9 +77,11 @@ int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque); void ram_block_notifier_add(RAMBlockNotifier *n); void ram_block_notifier_remove(RAMBlockNotifier *n); -void ram_block_notify_add(void *host, size_t size, size_t max_size); -void ram_block_notify_remove(void *host, size_t size, size_t max_size); -void ram_block_notify_resize(void *host, size_t old_size, size_t new_size); +void ram_block_notify_add(const RAMBlock *rb, + void *host, size_t size, size_t max_size); +void ram_block_notify_remove(const RAMBlock *rb, + void *host, size_t size, size_t max_size); +void ram_block_notify_resize(RAMBlock *rb, size_t new_size); GString *ram_block_format(void); diff --git a/block/block-ram-registrar.c b/block/block-ram-registrar.c index fcda2b86afb2..5b938de22587 100644 --- a/block/block-ram-registrar.c +++ b/block/block-ram-registrar.c @@ -9,8 +9,8 @@ #include "system/block-ram-registrar.h" #include "qapi/error.h" -static void ram_block_added(RAMBlockNotifier *n, void *host, size_t size, - size_t max_size) +static void ram_block_added(RAMBlockNotifier *n, const RAMBlock *rb, + void *host, size_t size, size_t max_size) { BlockRAMRegistrar *r = container_of(n, BlockRAMRegistrar, notifier); Error *err = NULL; @@ -26,8 +26,8 @@ static void ram_block_added(RAMBlockNotifier *n, void *host, size_t size, } } -static void ram_block_removed(RAMBlockNotifier *n, void *host, size_t size, - size_t max_size) +static void ram_block_removed(RAMBlockNotifier *n, const RAMBlock *rb, + void *host, size_t size, size_t max_size) { BlockRAMRegistrar *r = container_of(n, BlockRAMRegistrar, notifier); blk_unregister_buf(r->blk, host, max_size); diff --git a/hw/core/numa.c b/hw/core/numa.c index f462883c87cf..40acb98bdd0b 100644 --- a/hw/core/numa.c +++ b/hw/core/numa.c @@ -824,7 +824,7 @@ static int ram_block_notify_add_single(RAMBlock *rb, void *opaque) RAMBlockNotifier *notifier = opaque; if (host) { - notifier->ram_block_added(notifier, host, size, max_size); + notifier->ram_block_added(notifier, rb, host, size, max_size); } return 0; } @@ -837,7 +837,7 @@ static int ram_block_notify_remove_single(RAMBlock *rb, void *opaque) RAMBlockNotifier *notifier = opaque; if (host) { - notifier->ram_block_removed(notifier, host, size, max_size); + notifier->ram_block_removed(notifier, rb, host, size, max_size); } return 0; } @@ -861,38 +861,40 @@ void ram_block_notifier_remove(RAMBlockNotifier *n) } } -void ram_block_notify_add(void *host, size_t size, size_t max_size) +void ram_block_notify_add(const RAMBlock *rb, + void *host, size_t size, size_t max_size) { RAMBlockNotifier *notifier; RAMBlockNotifier *next; QLIST_FOREACH_SAFE(notifier, &ram_list.ramblock_notifiers, next, next) { if (notifier->ram_block_added) { - notifier->ram_block_added(notifier, host, size, max_size); + notifier->ram_block_added(notifier, rb, host, size, max_size); } } } -void ram_block_notify_remove(void *host, size_t size, size_t max_size) +void ram_block_notify_remove(const RAMBlock *rb, + void *host, size_t size, size_t max_size) { RAMBlockNotifier *notifier; RAMBlockNotifier *next; QLIST_FOREACH_SAFE(notifier, &ram_list.ramblock_notifiers, next, next) { if (notifier->ram_block_removed) { - notifier->ram_block_removed(notifier, host, size, max_size); + notifier->ram_block_removed(notifier, rb, host, size, max_size); } } } -void ram_block_notify_resize(void *host, size_t old_size, size_t new_size) +void ram_block_notify_resize(RAMBlock *rb, size_t new_size) { RAMBlockNotifier *notifier; RAMBlockNotifier *next; QLIST_FOREACH_SAFE(notifier, &ram_list.ramblock_notifiers, next, next) { if (notifier->ram_block_resized) { - notifier->ram_block_resized(notifier, host, old_size, new_size); + notifier->ram_block_resized(notifier, rb, new_size); } } } diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c index 85cf0cf359ca..f321c65b630e 100644 --- a/hw/xen/xen-mapcache.c +++ b/hw/xen/xen-mapcache.c @@ -222,7 +222,7 @@ static void xen_remap_bucket(MapCache *mc, if (entry->vaddr_base != NULL) { if (!(entry->flags & XEN_MAPCACHE_ENTRY_DUMMY)) { - ram_block_notify_remove(entry->vaddr_base, entry->size, + ram_block_notify_remove(NULL, entry->vaddr_base, entry->size, entry->size); } @@ -308,7 +308,7 @@ static void xen_remap_bucket(MapCache *mc, } if (!(entry->flags & XEN_MAPCACHE_ENTRY_DUMMY)) { - ram_block_notify_add(vaddr_base, size, size); + ram_block_notify_add(NULL, vaddr_base, size, size); } entry->vaddr_base = vaddr_base; @@ -601,7 +601,7 @@ static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc, return; } - ram_block_notify_remove(entry->vaddr_base, entry->size, entry->size); + ram_block_notify_remove(NULL, entry->vaddr_base, entry->size, entry->size); if (entry->flags & XEN_MAPCACHE_ENTRY_GRANT) { rc = xengnttab_unmap(xen_region_gnttabdev, entry->vaddr_base, entry->size >> mc->bucket_shift); diff --git a/migration/ram.c b/migration/ram.c index fc38ffbf8af1..6bc7f705d31a 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -4699,18 +4699,12 @@ static SaveVMHandlers savevm_ram_handlers = { .save_postcopy_prepare = ram_save_postcopy_prepare, }; -static void ram_mig_ram_block_resized(RAMBlockNotifier *n, void *host, - size_t old_size, size_t new_size) +static void ram_mig_ram_block_resized(RAMBlockNotifier *n, RAMBlock *rb, + size_t new_size) { PostcopyState ps = postcopy_state_get(); - ram_addr_t offset; - RAMBlock *rb = qemu_ram_block_from_host(host, false, &offset); Error *err = NULL; - - if (!rb) { - error_report("RAM block not found"); - return; - } + ram_addr_t old_size = qemu_ram_get_used_length(rb); if (migrate_ram_is_ignored(rb)) { return; diff --git a/system/physmem.c b/system/physmem.c index 7bcbf8757361..6d00e99270c7 100644 --- a/system/physmem.c +++ b/system/physmem.c @@ -2019,7 +2019,6 @@ static int memory_try_enable_merging(void *addr, size_t len) */ int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp) { - const ram_addr_t oldsize = block->used_length; const ram_addr_t unaligned_size = newsize; newsize = TARGET_PAGE_ALIGN(newsize); @@ -2057,7 +2056,7 @@ int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp) /* Notify before modifying the ram block and touching the bitmaps. */ if (block->host) { - ram_block_notify_resize(block->host, oldsize, newsize); + ram_block_notify_resize(block, newsize); } physical_memory_clear_dirty_range(block->offset, block->used_length); @@ -2283,7 +2282,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp) qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_DONTFORK); } - ram_block_notify_add(new_block->host, new_block->used_length, + ram_block_notify_add(new_block, new_block->host, new_block->used_length, new_block->max_length); } return; @@ -2600,7 +2599,7 @@ void qemu_ram_free(RAMBlock *block) } if (block->host) { - ram_block_notify_remove(block->host, block->used_length, + ram_block_notify_remove(block, block->host, block->used_length, block->max_length); } diff --git a/target/i386/nvmm/nvmm-all.c b/target/i386/nvmm/nvmm-all.c index 8a1af35ed32b..f29b9c504ea8 100644 --- a/target/i386/nvmm/nvmm-all.c +++ b/target/i386/nvmm/nvmm-all.c @@ -1134,8 +1134,8 @@ static MemoryListener nvmm_memory_listener = { }; static void -nvmm_ram_block_added(RAMBlockNotifier *n, void *host, size_t size, - size_t max_size) +nvmm_ram_block_added(RAMBlockNotifier *n, const RAMBlock *rb, + void *host, size_t size, size_t max_size) { struct nvmm_machine *mach = get_nvmm_mach(); uintptr_t hva = (uintptr_t)host; diff --git a/target/i386/sev.c b/target/i386/sev.c index b44b5a1c2b94..63d8d36b6d41 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -329,8 +329,8 @@ sev_set_guest_state(SevCommonState *sev_common, SevState new_state) } static void -sev_ram_block_added(RAMBlockNotifier *n, void *host, size_t size, - size_t max_size) +sev_ram_block_added(RAMBlockNotifier *n, const RAMBlock *rb, + void *host, size_t size, size_t max_size) { int r; struct kvm_enc_region range; @@ -359,8 +359,8 @@ sev_ram_block_added(RAMBlockNotifier *n, void *host, size_t size, } static void -sev_ram_block_removed(RAMBlockNotifier *n, void *host, size_t size, - size_t max_size) +sev_ram_block_removed(RAMBlockNotifier *n, const RAMBlock *rb, + void *host, size_t size, size_t max_size) { int r; struct kvm_enc_region range; diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c index aab0bf9d485d..5059ed44b8af 100644 --- a/util/vfio-helpers.c +++ b/util/vfio-helpers.c @@ -465,8 +465,8 @@ fail_container: return ret; } -static void qemu_vfio_ram_block_added(RAMBlockNotifier *n, void *host, - size_t size, size_t max_size) +static void qemu_vfio_ram_block_added(RAMBlockNotifier *n, const RAMBlock *rb, + void *host, size_t size, size_t max_size) { QEMUVFIOState *s = container_of(n, QEMUVFIOState, ram_notifier); Error *local_err = NULL; @@ -481,7 +481,8 @@ static void qemu_vfio_ram_block_added(RAMBlockNotifier *n, void *host, } } -static void qemu_vfio_ram_block_removed(RAMBlockNotifier *n, void *host, +static void qemu_vfio_ram_block_removed(RAMBlockNotifier *n, const RAMBlock *rb, + void *host, size_t size, size_t max_size) { QEMUVFIOState *s = container_of(n, QEMUVFIOState, ram_notifier); -- 2.54.0
