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Diffstat (limited to 'migration/postcopy-ram.c')
-rw-r--r--migration/postcopy-ram.c209
1 files changed, 156 insertions, 53 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 1089814d54..6ce157741f 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -533,29 +533,44 @@ static void *postcopy_ram_fault_thread(void *opaque)
MigrationIncomingState *mis = opaque;
struct uffd_msg msg;
int ret;
+ size_t index;
RAMBlock *rb = NULL;
RAMBlock *last_rb = NULL; /* last RAMBlock we sent part of */
trace_postcopy_ram_fault_thread_entry();
qemu_sem_post(&mis->fault_thread_sem);
+ struct pollfd *pfd;
+ size_t pfd_len = 2 + mis->postcopy_remote_fds->len;
+
+ pfd = g_new0(struct pollfd, pfd_len);
+
+ pfd[0].fd = mis->userfault_fd;
+ pfd[0].events = POLLIN;
+ pfd[1].fd = mis->userfault_event_fd;
+ pfd[1].events = POLLIN; /* Waiting for eventfd to go positive */
+ trace_postcopy_ram_fault_thread_fds_core(pfd[0].fd, pfd[1].fd);
+ for (index = 0; index < mis->postcopy_remote_fds->len; index++) {
+ struct PostCopyFD *pcfd = &g_array_index(mis->postcopy_remote_fds,
+ struct PostCopyFD, index);
+ pfd[2 + index].fd = pcfd->fd;
+ pfd[2 + index].events = POLLIN;
+ trace_postcopy_ram_fault_thread_fds_extra(2 + index, pcfd->idstr,
+ pcfd->fd);
+ }
+
while (true) {
ram_addr_t rb_offset;
- struct pollfd pfd[2];
+ int poll_result;
/*
* We're mainly waiting for the kernel to give us a faulting HVA,
* however we can be told to quit via userfault_quit_fd which is
* an eventfd
*/
- pfd[0].fd = mis->userfault_fd;
- pfd[0].events = POLLIN;
- pfd[0].revents = 0;
- pfd[1].fd = mis->userfault_event_fd;
- pfd[1].events = POLLIN; /* Waiting for eventfd to go positive */
- pfd[1].revents = 0;
-
- if (poll(pfd, 2, -1 /* Wait forever */) == -1) {
+
+ poll_result = poll(pfd, pfd_len, -1 /* Wait forever */);
+ if (poll_result == -1) {
error_report("%s: userfault poll: %s", __func__, strerror(errno));
break;
}
@@ -575,57 +590,117 @@ static void *postcopy_ram_fault_thread(void *opaque)
}
}
- ret = read(mis->userfault_fd, &msg, sizeof(msg));
- if (ret != sizeof(msg)) {
- if (errno == EAGAIN) {
- /*
- * if a wake up happens on the other thread just after
- * the poll, there is nothing to read.
- */
- continue;
+ if (pfd[0].revents) {
+ poll_result--;
+ ret = read(mis->userfault_fd, &msg, sizeof(msg));
+ if (ret != sizeof(msg)) {
+ if (errno == EAGAIN) {
+ /*
+ * if a wake up happens on the other thread just after
+ * the poll, there is nothing to read.
+ */
+ continue;
+ }
+ if (ret < 0) {
+ error_report("%s: Failed to read full userfault "
+ "message: %s",
+ __func__, strerror(errno));
+ break;
+ } else {
+ error_report("%s: Read %d bytes from userfaultfd "
+ "expected %zd",
+ __func__, ret, sizeof(msg));
+ break; /* Lost alignment, don't know what we'd read next */
+ }
}
- if (ret < 0) {
- error_report("%s: Failed to read full userfault message: %s",
- __func__, strerror(errno));
- break;
- } else {
- error_report("%s: Read %d bytes from userfaultfd expected %zd",
- __func__, ret, sizeof(msg));
- break; /* Lost alignment, don't know what we'd read next */
+ if (msg.event != UFFD_EVENT_PAGEFAULT) {
+ error_report("%s: Read unexpected event %ud from userfaultfd",
+ __func__, msg.event);
+ continue; /* It's not a page fault, shouldn't happen */
}
- }
- if (msg.event != UFFD_EVENT_PAGEFAULT) {
- error_report("%s: Read unexpected event %ud from userfaultfd",
- __func__, msg.event);
- continue; /* It's not a page fault, shouldn't happen */
- }
- rb = qemu_ram_block_from_host(
- (void *)(uintptr_t)msg.arg.pagefault.address,
- true, &rb_offset);
- if (!rb) {
- error_report("postcopy_ram_fault_thread: Fault outside guest: %"
- PRIx64, (uint64_t)msg.arg.pagefault.address);
- break;
- }
+ rb = qemu_ram_block_from_host(
+ (void *)(uintptr_t)msg.arg.pagefault.address,
+ true, &rb_offset);
+ if (!rb) {
+ error_report("postcopy_ram_fault_thread: Fault outside guest: %"
+ PRIx64, (uint64_t)msg.arg.pagefault.address);
+ break;
+ }
- rb_offset &= ~(qemu_ram_pagesize(rb) - 1);
- trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address,
+ rb_offset &= ~(qemu_ram_pagesize(rb) - 1);
+ trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address,
qemu_ram_get_idstr(rb),
rb_offset);
+ /*
+ * Send the request to the source - we want to request one
+ * of our host page sizes (which is >= TPS)
+ */
+ if (rb != last_rb) {
+ last_rb = rb;
+ migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb),
+ rb_offset, qemu_ram_pagesize(rb));
+ } else {
+ /* Save some space */
+ migrate_send_rp_req_pages(mis, NULL,
+ rb_offset, qemu_ram_pagesize(rb));
+ }
+ }
- /*
- * Send the request to the source - we want to request one
- * of our host page sizes (which is >= TPS)
- */
- if (rb != last_rb) {
- last_rb = rb;
- migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb),
- rb_offset, qemu_ram_pagesize(rb));
- } else {
- /* Save some space */
- migrate_send_rp_req_pages(mis, NULL,
- rb_offset, qemu_ram_pagesize(rb));
+ /* Now handle any requests from external processes on shared memory */
+ /* TODO: May need to handle devices deregistering during postcopy */
+ for (index = 2; index < pfd_len && poll_result; index++) {
+ if (pfd[index].revents) {
+ struct PostCopyFD *pcfd =
+ &g_array_index(mis->postcopy_remote_fds,
+ struct PostCopyFD, index - 2);
+
+ poll_result--;
+ if (pfd[index].revents & POLLERR) {
+ error_report("%s: POLLERR on poll %zd fd=%d",
+ __func__, index, pcfd->fd);
+ pfd[index].events = 0;
+ continue;
+ }
+
+ ret = read(pcfd->fd, &msg, sizeof(msg));
+ if (ret != sizeof(msg)) {
+ if (errno == EAGAIN) {
+ /*
+ * if a wake up happens on the other thread just after
+ * the poll, there is nothing to read.
+ */
+ continue;
+ }
+ if (ret < 0) {
+ error_report("%s: Failed to read full userfault "
+ "message: %s (shared) revents=%d",
+ __func__, strerror(errno),
+ pfd[index].revents);
+ /*TODO: Could just disable this sharer */
+ break;
+ } else {
+ error_report("%s: Read %d bytes from userfaultfd "
+ "expected %zd (shared)",
+ __func__, ret, sizeof(msg));
+ /*TODO: Could just disable this sharer */
+ break; /*Lost alignment,don't know what we'd read next*/
+ }
+ }
+ if (msg.event != UFFD_EVENT_PAGEFAULT) {
+ error_report("%s: Read unexpected event %ud "
+ "from userfaultfd (shared)",
+ __func__, msg.event);
+ continue; /* It's not a page fault, shouldn't happen */
+ }
+ /* Call the device handler registered with us */
+ ret = pcfd->handler(pcfd, &msg);
+ if (ret) {
+ error_report("%s: Failed to resolve shared fault on %zd/%s",
+ __func__, index, pcfd->idstr);
+ /* TODO: Fail? Disable this sharer? */
+ }
+ }
}
}
trace_postcopy_ram_fault_thread_exit();
@@ -970,3 +1045,31 @@ PostcopyState postcopy_state_set(PostcopyState new_state)
{
return atomic_xchg(&incoming_postcopy_state, new_state);
}
+
+/* Register a handler for external shared memory postcopy
+ * called on the destination.
+ */
+void postcopy_register_shared_ufd(struct PostCopyFD *pcfd)
+{
+ MigrationIncomingState *mis = migration_incoming_get_current();
+
+ mis->postcopy_remote_fds = g_array_append_val(mis->postcopy_remote_fds,
+ *pcfd);
+}
+
+/* Unregister a handler for external shared memory postcopy
+ */
+void postcopy_unregister_shared_ufd(struct PostCopyFD *pcfd)
+{
+ guint i;
+ MigrationIncomingState *mis = migration_incoming_get_current();
+ GArray *pcrfds = mis->postcopy_remote_fds;
+
+ for (i = 0; i < pcrfds->len; i++) {
+ struct PostCopyFD *cur = &g_array_index(pcrfds, struct PostCopyFD, i);
+ if (cur->fd == pcfd->fd) {
+ mis->postcopy_remote_fds = g_array_remove_index(pcrfds, i);
+ return;
+ }
+ }
+}
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-13 09:08:02 +0000