@@ -42,6 +42,7 @@ typedef struct SpaprXive {
/* KVM support */
int fd;
void *tm_mmap;
+ VMChangeStateEntry *change;
} SpaprXive;
/*
@@ -431,9 +431,100 @@ static void kvmppc_xive_get_queues(SpaprXive *xive, Error **errp)
}
}
+/*
+ * The primary goal of the XIVE VM change handler is to mark the EQ
+ * pages dirty when all XIVE event notifications have stopped.
+ *
+ * Whenever the VM is stopped, the VM change handler sets the source
+ * PQs to PENDING to stop the flow of events and to possibly catch a
+ * triggered interrupt occuring while the VM is stopped. The previous
+ * state is saved in anticipation of a migration. The XIVE controller
+ * is then synced through KVM to flush any in-flight event
+ * notification and stabilize the EQs.
+ *
+ * At this stage, we can mark the EQ page dirty and let a migration
+ * sequence transfer the EQ pages to the destination, which is done
+ * just after the stop state.
+ *
+ * The previous configuration of the sources is restored when the VM
+ * runs again. If an interrupt was queued while the VM was stopped,
+ * simply generate a trigger.
+ */
+static void kvmppc_xive_change_state_handler(void *opaque, int running,
+ RunState state)
+{
+ SpaprXive *xive = opaque;
+ XiveSource *xsrc = &xive->source;
+ Error *local_err = NULL;
+ int i;
+
+ /*
+ * Restore the sources to their initial state. This is called when
+ * the VM resumes after a stop or a migration.
+ */
+ if (running) {
+ for (i = 0; i < xsrc->nr_irqs; i++) {
+ uint8_t pq = xive_source_esb_get(xsrc, i);
+ uint8_t old_pq;
+
+ old_pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_00 + (pq << 8));
+
+ /*
+ * An interrupt was queued while the VM was stopped,
+ * generate a trigger.
+ */
+ if (pq == XIVE_ESB_RESET && old_pq == XIVE_ESB_QUEUED) {
+ xive_esb_trigger(xsrc, i);
+ }
+ }
+
+ return;
+ }
+
+ /*
+ * Mask the sources, to stop the flow of event notifications, and
+ * save the PQs locally in the XiveSource object. The XiveSource
+ * state will be collected later on by its vmstate handler if a
+ * migration is in progress.
+ */
+ for (i = 0; i < xsrc->nr_irqs; i++) {
+ uint8_t pq = xive_esb_read(xsrc, i, XIVE_ESB_GET);
+
+ /*
+ * PQ is set to PENDING to possibly catch a triggered
+ * interrupt occuring while the VM is stopped (hotplug event
+ * for instance) .
+ */
+ if (pq != XIVE_ESB_OFF) {
+ pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_10);
+ }
+ xive_source_esb_set(xsrc, i, pq);
+ }
+
+ /*
+ * Sync the XIVE controller in KVM, to flush in-flight event
+ * notification that should be enqueued in the EQs and mark the
+ * XIVE EQ pages dirty to collect all updates.
+ */
+ kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL,
+ KVM_DEV_XIVE_EQ_SYNC, NULL, true, &local_err);
+ if (local_err) {
+ error_report_err(local_err);
+ return;
+ }
+}
+
void kvmppc_xive_synchronize_state(SpaprXive *xive, Error **errp)
{
- kvmppc_xive_source_get_state(&xive->source);
+ /*
+ * When the VM is stopped, the sources are masked and the previous
+ * state is saved in anticipation of a migration. We should not
+ * synchronize the source state in that case else we will override
+ * the saved state.
+ */
+ if (runstate_is_running()) {
+ kvmppc_xive_source_get_state(&xive->source);
+ }
/* EAT: there is no extra state to query from KVM */
@@ -513,6 +604,9 @@ void kvmppc_xive_connect(SpaprXive *xive, Error **errp)
"xive.tima", tima_len, xive->tm_mmap);
sysbus_init_mmio(SYS_BUS_DEVICE(xive), &xive->tm_mmio);
+ xive->change = qemu_add_vm_change_state_handler(
+ kvmppc_xive_change_state_handler, xive);
+
kvm_kernel_irqchip = true;
kvm_msi_via_irqfd_allowed = true;
kvm_gsi_direct_mapping = true;