diff options
Diffstat (limited to 'migration/postcopy-ram.c')
| -rw-r--r-- | migration/postcopy-ram.c | 142 |
1 files changed, 66 insertions, 76 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index a40dddbaf6..effbeb64fb 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -81,25 +81,18 @@ static bool ufd_version_check(int ufd) return false; } - return true; -} - -/* - * Check for things that postcopy won't support; returns 0 if the block - * is fine. - */ -static int check_range(const char *block_name, void *host_addr, - ram_addr_t offset, ram_addr_t length, void *opaque) -{ - RAMBlock *rb = qemu_ram_block_by_name(block_name); - - if (qemu_ram_pagesize(rb) > getpagesize()) { - error_report("Postcopy doesn't support large page sizes yet (%s)", - block_name); - return -E2BIG; + if (getpagesize() != ram_pagesize_summary()) { + bool have_hp = false; + /* We've got a huge page */ +#ifdef UFFD_FEATURE_MISSING_HUGETLBFS + have_hp = api_struct.features & UFFD_FEATURE_MISSING_HUGETLBFS; +#endif + if (!have_hp) { + error_report("Userfault on this host does not support huge pages"); + return false; + } } - - return 0; + return true; } /* @@ -122,12 +115,6 @@ bool postcopy_ram_supported_by_host(void) goto out; } - /* Check for anything about the RAMBlocks we don't support */ - if (qemu_ram_foreach_block(check_range, NULL)) { - /* check_range will have printed its own error */ - goto out; - } - ufd = syscall(__NR_userfaultfd, O_CLOEXEC); if (ufd == -1) { error_report("%s: userfaultfd not available: %s", __func__, @@ -200,27 +187,6 @@ out: return ret; } -/** - * postcopy_ram_discard_range: Discard a range of memory. - * We can assume that if we've been called postcopy_ram_hosttest returned true. - * - * @mis: Current incoming migration state. - * @start, @length: range of memory to discard. - * - * returns: 0 on success. - */ -int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start, - size_t length) -{ - trace_postcopy_ram_discard_range(start, length); - if (madvise(start, length, MADV_DONTNEED)) { - error_report("%s MADV_DONTNEED: %s", __func__, strerror(errno)); - return -1; - } - - return 0; -} - /* * Setup an area of RAM so that it *can* be used for postcopy later; this * must be done right at the start prior to pre-copy. @@ -239,7 +205,7 @@ static int init_range(const char *block_name, void *host_addr, * - we're going to get the copy from the source anyway. * (Precopy will just overwrite this data, so doesn't need the discard) */ - if (postcopy_ram_discard_range(mis, host_addr, length)) { + if (ram_discard_range(mis, block_name, 0, length)) { return -1; } @@ -342,9 +308,13 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0); if (mis->postcopy_tmp_page) { - munmap(mis->postcopy_tmp_page, getpagesize()); + munmap(mis->postcopy_tmp_page, mis->largest_page_size); mis->postcopy_tmp_page = NULL; } + if (mis->postcopy_tmp_zero_page) { + munmap(mis->postcopy_tmp_zero_page, mis->largest_page_size); + mis->postcopy_tmp_zero_page = NULL; + } trace_postcopy_ram_incoming_cleanup_exit(); return 0; } @@ -408,6 +378,10 @@ static int ram_block_enable_notify(const char *block_name, void *host_addr, error_report("%s userfault register: %s", __func__, strerror(errno)); return -1; } + if (!(reg_struct.ioctls & ((__u64)1 << _UFFDIO_COPY))) { + error_report("%s userfault: Region doesn't support COPY", __func__); + return -1; + } return 0; } @@ -420,7 +394,6 @@ static void *postcopy_ram_fault_thread(void *opaque) MigrationIncomingState *mis = opaque; struct uffd_msg msg; int ret; - size_t hostpagesize = getpagesize(); RAMBlock *rb = NULL; RAMBlock *last_rb = NULL; /* last RAMBlock we sent part of */ @@ -487,7 +460,7 @@ static void *postcopy_ram_fault_thread(void *opaque) break; } - rb_offset &= ~(hostpagesize - 1); + rb_offset &= ~(qemu_ram_pagesize(rb) - 1); trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address, qemu_ram_get_idstr(rb), rb_offset); @@ -499,11 +472,11 @@ static void *postcopy_ram_fault_thread(void *opaque) if (rb != last_rb) { last_rb = rb; migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb), - rb_offset, hostpagesize); + rb_offset, qemu_ram_pagesize(rb)); } else { /* Save some space */ migrate_send_rp_req_pages(mis, NULL, - rb_offset, hostpagesize); + rb_offset, qemu_ram_pagesize(rb)); } } trace_postcopy_ram_fault_thread_exit(); @@ -564,13 +537,14 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis) * Place a host page (from) at (host) atomically * returns 0 on success */ -int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from) +int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from, + size_t pagesize) { struct uffdio_copy copy_struct; copy_struct.dst = (uint64_t)(uintptr_t)host; copy_struct.src = (uint64_t)(uintptr_t)from; - copy_struct.len = getpagesize(); + copy_struct.len = pagesize; copy_struct.mode = 0; /* copy also acks to the kernel waking the stalled thread up @@ -580,8 +554,8 @@ int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from) */ if (ioctl(mis->userfault_fd, UFFDIO_COPY, ©_struct)) { int e = errno; - error_report("%s: %s copy host: %p from: %p", - __func__, strerror(e), host, from); + error_report("%s: %s copy host: %p from: %p (size: %zd)", + __func__, strerror(e), host, from, pagesize); return -e; } @@ -594,23 +568,44 @@ int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from) * Place a zero page at (host) atomically * returns 0 on success */ -int postcopy_place_page_zero(MigrationIncomingState *mis, void *host) +int postcopy_place_page_zero(MigrationIncomingState *mis, void *host, + size_t pagesize) { - struct uffdio_zeropage zero_struct; + trace_postcopy_place_page_zero(host); - zero_struct.range.start = (uint64_t)(uintptr_t)host; - zero_struct.range.len = getpagesize(); - zero_struct.mode = 0; + if (pagesize == getpagesize()) { + struct uffdio_zeropage zero_struct; + zero_struct.range.start = (uint64_t)(uintptr_t)host; + zero_struct.range.len = getpagesize(); + zero_struct.mode = 0; - if (ioctl(mis->userfault_fd, UFFDIO_ZEROPAGE, &zero_struct)) { - int e = errno; - error_report("%s: %s zero host: %p", - __func__, strerror(e), host); + if (ioctl(mis->userfault_fd, UFFDIO_ZEROPAGE, &zero_struct)) { + int e = errno; + error_report("%s: %s zero host: %p", + __func__, strerror(e), host); - return -e; + return -e; + } + } else { + /* The kernel can't use UFFDIO_ZEROPAGE for hugepages */ + if (!mis->postcopy_tmp_zero_page) { + mis->postcopy_tmp_zero_page = mmap(NULL, mis->largest_page_size, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, + -1, 0); + if (mis->postcopy_tmp_zero_page == MAP_FAILED) { + int e = errno; + mis->postcopy_tmp_zero_page = NULL; + error_report("%s: %s mapping large zero page", + __func__, strerror(e)); + return -e; + } + memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_size); + } + return postcopy_place_page(mis, host, mis->postcopy_tmp_zero_page, + pagesize); } - trace_postcopy_place_page_zero(host); return 0; } @@ -625,7 +620,7 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host) void *postcopy_get_tmp_page(MigrationIncomingState *mis) { if (!mis->postcopy_tmp_page) { - mis->postcopy_tmp_page = mmap(NULL, getpagesize(), + mis->postcopy_tmp_page = mmap(NULL, mis->largest_page_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (mis->postcopy_tmp_page == MAP_FAILED) { @@ -658,13 +653,6 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) return -1; } -int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start, - size_t length) -{ - assert(0); - return -1; -} - int postcopy_ram_prepare_discard(MigrationIncomingState *mis) { assert(0); @@ -677,13 +665,15 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis) return -1; } -int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from) +int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from, + size_t pagesize) { assert(0); return -1; } -int postcopy_place_page_zero(MigrationIncomingState *mis, void *host) +int postcopy_place_page_zero(MigrationIncomingState *mis, void *host, + size_t pagesize) { assert(0); return -1; |