diff options
Diffstat (limited to 'migration/postcopy-ram.c')
| -rw-r--r-- | migration/postcopy-ram.c | 40 |
1 files changed, 31 insertions, 9 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 2e9697bdd2..e721f69d0f 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -402,7 +402,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis) strerror(errno)); goto out; } - g_assert(((size_t)testarea & (pagesize - 1)) == 0); + g_assert(QEMU_PTR_IS_ALIGNED(testarea, pagesize)); reg_struct.range.start = (uintptr_t)testarea; reg_struct.range.len = pagesize; @@ -660,7 +660,7 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd, struct uffdio_range range; int ret; trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb)); - range.start = client_addr & ~(pagesize - 1); + range.start = ROUND_DOWN(client_addr, pagesize); range.len = pagesize; ret = ioctl(pcfd->fd, UFFDIO_WAKE, &range); if (ret) { @@ -671,6 +671,29 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd, return ret; } +static int postcopy_request_page(MigrationIncomingState *mis, RAMBlock *rb, + ram_addr_t start, uint64_t haddr) +{ + void *aligned = (void *)(uintptr_t)ROUND_DOWN(haddr, qemu_ram_pagesize(rb)); + + /* + * Discarded pages (via RamDiscardManager) are never migrated. On unlikely + * access, place a zeropage, which will also set the relevant bits in the + * recv_bitmap accordingly, so we won't try placing a zeropage twice. + * + * Checking a single bit is sufficient to handle pagesize > TPS as either + * all relevant bits are set or not. + */ + assert(QEMU_IS_ALIGNED(start, qemu_ram_pagesize(rb))); + if (ramblock_page_is_discarded(rb, start)) { + bool received = ramblock_recv_bitmap_test_byte_offset(rb, start); + + return received ? 0 : postcopy_place_page_zero(mis, aligned, rb); + } + + return migrate_send_rp_req_pages(mis, rb, start, haddr); +} + /* * Callback from shared fault handlers to ask for a page, * the page must be specified by a RAMBlock and an offset in that rb @@ -679,8 +702,7 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd, int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb, uint64_t client_addr, uint64_t rb_offset) { - size_t pagesize = qemu_ram_pagesize(rb); - uint64_t aligned_rbo = rb_offset & ~(pagesize - 1); + uint64_t aligned_rbo = ROUND_DOWN(rb_offset, qemu_ram_pagesize(rb)); MigrationIncomingState *mis = migration_incoming_get_current(); trace_postcopy_request_shared_page(pcfd->idstr, qemu_ram_get_idstr(rb), @@ -690,7 +712,7 @@ int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb, qemu_ram_get_idstr(rb), rb_offset); return postcopy_wake_shared(pcfd, client_addr, rb); } - migrate_send_rp_req_pages(mis, rb, aligned_rbo, client_addr); + postcopy_request_page(mis, rb, aligned_rbo, client_addr); return 0; } @@ -970,7 +992,7 @@ static void *postcopy_ram_fault_thread(void *opaque) break; } - rb_offset &= ~(qemu_ram_pagesize(rb) - 1); + rb_offset = ROUND_DOWN(rb_offset, qemu_ram_pagesize(rb)); trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address, qemu_ram_get_idstr(rb), rb_offset, @@ -984,8 +1006,8 @@ retry: * Send the request to the source - we want to request one * of our host page sizes (which is >= TPS) */ - ret = migrate_send_rp_req_pages(mis, rb, rb_offset, - msg.arg.pagefault.address); + ret = postcopy_request_page(mis, rb, rb_offset, + msg.arg.pagefault.address); if (ret) { /* May be network failure, try to wait for recovery */ if (ret == -EIO && postcopy_pause_fault_thread(mis)) { @@ -993,7 +1015,7 @@ retry: goto retry; } else { /* This is a unavoidable fault */ - error_report("%s: migrate_send_rp_req_pages() get %d", + error_report("%s: postcopy_request_page() get %d", __func__, ret); break; } |