Merge tag 'migration-staging-pull-request' of https://gitlab.com/pete…

…rx/qemu into staging

Migration pull

- William's fix on hwpoison migration which used to crash QEMU
- Peter's multifd cleanup + bugfix + optimizations
- Avihai's fix on multifd crash over non-socket channels
- Fabiano's multifd thread-race fix
- Peter's CI fix series

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# gpg:                using EDDSA key B9184DC20CC457DACF7DD1A93B5FCCCDF3ABD706
# gpg:                issuer "peterx@redhat.com"
# gpg: Good signature from "Peter Xu <xzpeter@gmail.com>" [marginal]
# gpg:                 aka "Peter Xu <peterx@redhat.com>" [marginal]
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* tag 'migration-staging-pull-request' of https://gitlab.com/peterx/qemu: (34 commits)
  ci: Update comment for migration-compat-aarch64
  ci: Remove tag dependency for build-previous-qemu
  tests/migration-test: Stick with gicv3 in aarch64 test
  migration/multifd: Add a synchronization point for channel creation
  migration/multifd: Unify multifd and TLS connection paths
  migration/multifd: Move multifd_send_setup into migration thread
  migration/multifd: Move multifd_send_setup error handling in to the function
  migration/multifd: Remove p->running
  migration/multifd: Join the TLS thread
  migration: Fix logic of channels and transport compatibility check
  migration/multifd: Optimize sender side to be lockless
  migration/multifd: Fix MultiFDSendParams.packet_num race
  migration/multifd: Stick with send/recv on function names
  migration/multifd: Cleanup multifd_load_cleanup()
  migration/multifd: Cleanup multifd_save_cleanup()
  migration/multifd: Rewrite multifd_queue_page()
  migration/multifd: Change retval of multifd_send_pages()
  migration/multifd: Change retval of multifd_queue_page()
  migration/multifd: Split multifd_send_terminate_threads()
  migration/multifd: Forbid spurious wakeups
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

.gitlab-ci.d/buildtest.yml

@@ -189,6 +189,8 @@ build-previous-qemu:
     TARGETS: x86_64-softmmu aarch64-softmmu
   before_script:
     - export QEMU_PREV_VERSION="$(sed 's/\([0-9.]*\)\.[0-9]*/v\1.0/' VERSION)"
+    - git remote add upstream https://gitlab.com/qemu-project/qemu
+    - git fetch upstream $QEMU_PREV_VERSION
     - git checkout $QEMU_PREV_VERSION
   after_script:
     - mv build build-previous
@@ -217,9 +219,10 @@ build-previous-qemu:
     - QTEST_QEMU_BINARY_DST=./qemu-system-${TARGET}
           QTEST_QEMU_BINARY=../build/qemu-system-${TARGET} ./tests/qtest/migration-test
 
-# This job is disabled until we release 9.0. The existing
-# migration-test in 8.2 is broken on aarch64. The fix was already
-# commited, but it will only take effect once 9.0 is out.
+# This job needs to be disabled until we can have an aarch64 CPU model that
+# will both (1) support both KVM and TCG, and (2) provide a stable ABI.
+# Currently only "-cpu max" can provide (1), however it doesn't guarantee
+# (2).  Mark this test skipped until later.
 migration-compat-aarch64:
   extends: .migration-compat-common
   variables:

accel/kvm/kvm-all.c

@@ -1119,6 +1119,11 @@ int kvm_vm_check_extension(KVMState *s, unsigned int extension)
     return ret;
 }
 
+/*
+ * We track the poisoned pages to be able to:
+ * - replace them on VM reset
+ * - block a migration for a VM with a poisoned page
+ */
 typedef struct HWPoisonPage {
     ram_addr_t ram_addr;
     QLIST_ENTRY(HWPoisonPage) list;
@@ -1152,6 +1157,11 @@ void kvm_hwpoison_page_add(ram_addr_t ram_addr)
     QLIST_INSERT_HEAD(&hwpoison_page_list, page, list);
 }
 
+bool kvm_hwpoisoned_mem(void)
+{
+    return !QLIST_EMPTY(&hwpoison_page_list);
+}
+
 static uint32_t adjust_ioeventfd_endianness(uint32_t val, uint32_t size)
 {
 #if HOST_BIG_ENDIAN != TARGET_BIG_ENDIAN

accel/stubs/kvm-stub.c

@@ -124,3 +124,8 @@ uint32_t kvm_dirty_ring_size(void)
 {
     return 0;
 }
+
+bool kvm_hwpoisoned_mem(void)
+{
+    return false;
+}

include/sysemu/kvm.h

@@ -538,4 +538,10 @@ bool kvm_arch_cpu_check_are_resettable(void);
 bool kvm_dirty_ring_enabled(void);
 
 uint32_t kvm_dirty_ring_size(void);
+
+/**
+ * kvm_hwpoisoned_mem - indicate if there is any hwpoisoned page
+ * reported for the VM.
+ */
+bool kvm_hwpoisoned_mem(void);
 #endif

migration/migration.c

@@ -67,6 +67,7 @@
 #include "options.h"
 #include "sysemu/dirtylimit.h"
 #include "qemu/sockets.h"
+#include "sysemu/kvm.h"
 
 static NotifierList migration_state_notifiers =
     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
@@ -128,20 +129,25 @@ static bool migration_needs_multiple_sockets(void)
     return migrate_multifd() || migrate_postcopy_preempt();
 }
 
-static bool transport_supports_multi_channels(SocketAddress *saddr)
+static bool transport_supports_multi_channels(MigrationAddress *addr)
 {
-    return saddr->type == SOCKET_ADDRESS_TYPE_INET ||
-           saddr->type == SOCKET_ADDRESS_TYPE_UNIX ||
-           saddr->type == SOCKET_ADDRESS_TYPE_VSOCK;
+    if (addr->transport == MIGRATION_ADDRESS_TYPE_SOCKET) {
+        SocketAddress *saddr = &addr->u.socket;
+
+        return saddr->type == SOCKET_ADDRESS_TYPE_INET ||
+               saddr->type == SOCKET_ADDRESS_TYPE_UNIX ||
+               saddr->type == SOCKET_ADDRESS_TYPE_VSOCK;
+    }
+
+    return false;
 }
 
 static bool
 migration_channels_and_transport_compatible(MigrationAddress *addr,
                                             Error **errp)
 {
     if (migration_needs_multiple_sockets() &&
-        (addr->transport == MIGRATION_ADDRESS_TYPE_SOCKET) &&
-        !transport_supports_multi_channels(&addr->u.socket)) {
+        !transport_supports_multi_channels(addr)) {
         error_setg(errp, "Migration requires multi-channel URIs (e.g. tcp)");
         return false;
     }
@@ -311,7 +317,7 @@ void migration_incoming_state_destroy(void)
 {
     struct MigrationIncomingState *mis = migration_incoming_get_current();
 
-    multifd_load_cleanup();
+    multifd_recv_cleanup();
     compress_threads_load_cleanup();
 
     if (mis->to_src_file) {
@@ -662,7 +668,7 @@ static void process_incoming_migration_bh(void *opaque)
 
     trace_vmstate_downtime_checkpoint("dst-precopy-bh-announced");
 
-    multifd_load_shutdown();
+    multifd_recv_shutdown();
 
     dirty_bitmap_mig_before_vm_start();
 
@@ -759,7 +765,7 @@ process_incoming_migration_co(void *opaque)
                       MIGRATION_STATUS_FAILED);
     qemu_fclose(mis->from_src_file);
 
-    multifd_load_cleanup();
+    multifd_recv_cleanup();
     compress_threads_load_cleanup();
 
     exit(EXIT_FAILURE);
@@ -885,7 +891,7 @@ void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp)
         default_channel = !mis->from_src_file;
     }
 
-    if (multifd_load_setup(errp) != 0) {
+    if (multifd_recv_setup(errp) != 0) {
         return;
     }
 
@@ -1331,7 +1337,7 @@ static void migrate_fd_cleanup(MigrationState *s)
         }
         bql_lock();
 
-        multifd_save_cleanup();
+        multifd_send_shutdown();
         qemu_mutex_lock(&s->qemu_file_lock);
         tmp = s->to_dst_file;
         s->to_dst_file = NULL;
@@ -1906,6 +1912,12 @@ static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc,
         return false;
     }
 
+    if (kvm_hwpoisoned_mem()) {
+        error_setg(errp, "Can't migrate this vm with hardware poisoned memory, "
+                   "please reboot the vm and try again");
+        return false;
+    }
+
     if (migration_is_blocked(errp)) {
         return false;
     }
@@ -3315,6 +3327,10 @@ static void *migration_thread(void *opaque)
     object_ref(OBJECT(s));
     update_iteration_initial_status(s);
 
+    if (!multifd_send_setup()) {
+        goto out;
+    }
+
     bql_lock();
     qemu_savevm_state_header(s->to_dst_file);
     bql_unlock();
@@ -3386,6 +3402,7 @@ static void *migration_thread(void *opaque)
         urgent = migration_rate_limit();
     }
 
+out:
     trace_migration_thread_after_loop();
     migration_iteration_finish(s);
     object_unref(OBJECT(s));
@@ -3623,15 +3640,6 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
         return;
     }
 
-    if (multifd_save_setup(&local_err) != 0) {
-        migrate_set_error(s, local_err);
-        error_report_err(local_err);
-        migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
-                          MIGRATION_STATUS_FAILED);
-        migrate_fd_cleanup(s);
-        return;
-    }
-
     if (migrate_background_snapshot()) {
         qemu_thread_create(&s->thread, "bg_snapshot",
                 bg_migration_thread, s, QEMU_THREAD_JOINABLE);

migration/multifd-zlib.c

@@ -116,17 +116,20 @@ static void zlib_send_cleanup(MultiFDSendParams *p, Error **errp)
  */
 static int zlib_send_prepare(MultiFDSendParams *p, Error **errp)
 {
+    MultiFDPages_t *pages = p->pages;
     struct zlib_data *z = p->data;
     z_stream *zs = &z->zs;
     uint32_t out_size = 0;
     int ret;
     uint32_t i;
 
-    for (i = 0; i < p->normal_num; i++) {
+    multifd_send_prepare_header(p);
+
+    for (i = 0; i < pages->num; i++) {
         uint32_t available = z->zbuff_len - out_size;
         int flush = Z_NO_FLUSH;
 
-        if (i == p->normal_num - 1) {
+        if (i == pages->num - 1) {
             flush = Z_SYNC_FLUSH;
         }
 
@@ -135,7 +138,7 @@ static int zlib_send_prepare(MultiFDSendParams *p, Error **errp)
          * with compression. zlib does not guarantee that this is safe,
          * therefore copy the page before calling deflate().
          */
-        memcpy(z->buf, p->pages->block->host + p->normal[i], p->page_size);
+        memcpy(z->buf, p->pages->block->host + pages->offset[i], p->page_size);
         zs->avail_in = p->page_size;
         zs->next_in = z->buf;
 
@@ -171,6 +174,8 @@ static int zlib_send_prepare(MultiFDSendParams *p, Error **errp)
     p->next_packet_size = out_size;
     p->flags |= MULTIFD_FLAG_ZLIB;
 
+    multifd_send_fill_packet(p);
+
     return 0;
 }
 

migration/multifd-zstd.c

@@ -113,21 +113,24 @@ static void zstd_send_cleanup(MultiFDSendParams *p, Error **errp)
  */
 static int zstd_send_prepare(MultiFDSendParams *p, Error **errp)
 {
+    MultiFDPages_t *pages = p->pages;
     struct zstd_data *z = p->data;
     int ret;
     uint32_t i;
 
+    multifd_send_prepare_header(p);
+
     z->out.dst = z->zbuff;
     z->out.size = z->zbuff_len;
     z->out.pos = 0;
 
-    for (i = 0; i < p->normal_num; i++) {
+    for (i = 0; i < pages->num; i++) {
         ZSTD_EndDirective flush = ZSTD_e_continue;
 
-        if (i == p->normal_num - 1) {
+        if (i == pages->num - 1) {
             flush = ZSTD_e_flush;
         }
-        z->in.src = p->pages->block->host + p->normal[i];
+        z->in.src = p->pages->block->host + pages->offset[i];
         z->in.size = p->page_size;
         z->in.pos = 0;
 
@@ -160,6 +163,8 @@ static int zstd_send_prepare(MultiFDSendParams *p, Error **errp)
     p->next_packet_size = z->out.pos;
     p->flags |= MULTIFD_FLAG_ZSTD;
 
+    multifd_send_fill_packet(p);
+
     return 0;
 }