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envelope-from=steven.sistare@oracle.com; helo=mx0a-00069f02.pphosted.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_MED=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Unlike cpr-reboot mode, cpr-transfer mode cannot save volatile ram blocks in the migration stream file and recreate them later, because the physical memory for the blocks is pinned and registered for vfio. Add a blocker for volatile ram blocks. Also add a blocker for RAM_GUEST_MEMFD. Preserving guest_memfd may be sufficient for CPR, but it has not been tested yet. Signed-off-by: Steve Sistare Reviewed-by: Fabiano Rosas Reviewed-by: Peter Xu Reviewed-by: David Hildenbrand --- include/exec/memory.h | 3 +++ include/exec/ramblock.h | 1 + migration/savevm.c | 2 ++ system/physmem.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 72 insertions(+) diff --git a/include/exec/memory.h b/include/exec/memory.h index 9f73b59..ea5d33a 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -3184,6 +3184,9 @@ bool ram_block_discard_is_disabled(void); */ bool ram_block_discard_is_required(void); +void ram_block_add_cpr_blocker(RAMBlock *rb, Error **errp); +void ram_block_del_cpr_blocker(RAMBlock *rb); + #endif #endif diff --git a/include/exec/ramblock.h b/include/exec/ramblock.h index 0babd10..64484cd 100644 --- a/include/exec/ramblock.h +++ b/include/exec/ramblock.h @@ -39,6 +39,7 @@ struct RAMBlock { /* RCU-enabled, writes protected by the ramlist lock */ QLIST_ENTRY(RAMBlock) next; QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers; + Error *cpr_blocker; int fd; uint64_t fd_offset; int guest_memfd; diff --git a/migration/savevm.c b/migration/savevm.c index bc375db..85a3559 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -3315,12 +3315,14 @@ void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev) qemu_ram_set_idstr(mr->ram_block, memory_region_name(mr), dev); qemu_ram_set_migratable(mr->ram_block); + ram_block_add_cpr_blocker(mr->ram_block, &error_fatal); } void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev) { qemu_ram_unset_idstr(mr->ram_block); qemu_ram_unset_migratable(mr->ram_block); + ram_block_del_cpr_blocker(mr->ram_block); } void vmstate_register_ram_global(MemoryRegion *mr) diff --git a/system/physmem.c b/system/physmem.c index 67c9db9..0e84f14 100644 --- a/system/physmem.c +++ b/system/physmem.c @@ -70,7 +70,10 @@ #include "qemu/pmem.h" +#include "qapi/qapi-types-migration.h" +#include "migration/blocker.h" #include "migration/cpr.h" +#include "migration/options.h" #include "migration/vmstate.h" #include "qemu/range.h" @@ -1899,6 +1902,14 @@ static void ram_block_add(RAMBlock *new_block, Error **errp) qemu_mutex_unlock_ramlist(); goto out_free; } + + error_setg(&new_block->cpr_blocker, + "Memory region %s uses guest_memfd, " + "which is not supported with CPR.", + memory_region_name(new_block->mr)); + migrate_add_blocker_modes(&new_block->cpr_blocker, errp, + MIG_MODE_CPR_TRANSFER, + -1); } ram_size = (new_block->offset + new_block->max_length) >> TARGET_PAGE_BITS; @@ -4059,3 +4070,58 @@ bool ram_block_discard_is_required(void) return qatomic_read(&ram_block_discard_required_cnt) || qatomic_read(&ram_block_coordinated_discard_required_cnt); } + +/* + * Return true if ram is compatible with CPR. Do not exclude rom, + * because the rom file could change in new QEMU. + */ +static bool ram_is_cpr_compatible(RAMBlock *rb) +{ + MemoryRegion *mr = rb->mr; + + if (!mr || !memory_region_is_ram(mr)) { + return true; + } + + /* Ram device is remapped in new QEMU */ + if (memory_region_is_ram_device(mr)) { + return true; + } + + /* + * A file descriptor is passed to new QEMU and remapped, or its backing + * file is reopened and mapped. It must be shared to avoid COW. + */ + if (rb->fd >= 0 && qemu_ram_is_shared(rb)) { + return true; + } + + return false; +} + +/* + * Add a blocker for each volatile ram block. This function should only be + * called after we know that the block is migratable. Non-migratable blocks + * are either re-created in new QEMU, or are handled specially, or are covered + * by a device-level CPR blocker. + */ +void ram_block_add_cpr_blocker(RAMBlock *rb, Error **errp) +{ + assert(qemu_ram_is_migratable(rb)); + + if (ram_is_cpr_compatible(rb)) { + return; + } + + error_setg(&rb->cpr_blocker, + "Memory region %s is not compatible with CPR. share=on is " + "required for memory-backend objects, and aux-ram-share=on is " + "required.", memory_region_name(rb->mr)); + migrate_add_blocker_modes(&rb->cpr_blocker, errp, MIG_MODE_CPR_TRANSFER, + -1); +} + +void ram_block_del_cpr_blocker(RAMBlock *rb) +{ + migrate_del_blocker(&rb->cpr_blocker); +}