[Qemu-devel] [RFC 1/1] hw/pvrdma: Add live migration support

[Sukrit Bhatnagar]

Define and register SaveVMHandlers pvrdma_save and
pvrdma_load for saving and loading the device state,
which currently includes only the dma, command slot
and response slot addresses.

Remap the DSR, command slot and response slot upon
loading the addresses in the pvrdma_load function.

Cc: Marcel Apfelbaum <address@hidden>
Cc: Yuval Shaia <address@hidden>
Signed-off-by: Sukrit Bhatnagar <address@hidden>
---
 hw/rdma/vmw/pvrdma_main.c | 56 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/hw/rdma/vmw/pvrdma_main.c b/hw/rdma/vmw/pvrdma_main.c
index adcf79cd63..cd8573173c 100644
--- a/hw/rdma/vmw/pvrdma_main.c
+++ b/hw/rdma/vmw/pvrdma_main.c
@@ -28,6 +28,7 @@
 #include "sysemu/sysemu.h"
 #include "monitor/monitor.h"
 #include "hw/rdma/rdma.h"
+#include "migration/register.h"
 
 #include "../rdma_rm.h"
 #include "../rdma_backend.h"
@@ -592,9 +593,62 @@ static void pvrdma_shutdown_notifier(Notifier *n, void 
*opaque)
     pvrdma_fini(pci_dev);
 }
 
+static void pvrdma_save(QEMUFile *f, void *opaque)
+{
+    PVRDMADev *dev = PVRDMA_DEV(opaque);
+
+    qemu_put_be64(f, dev->dsr_info.dma);
+    qemu_put_be64(f, dev->dsr_info.dsr->cmd_slot_dma);
+    qemu_put_be64(f, dev->dsr_info.dsr->resp_slot_dma);
+}
+
+static int pvrdma_load(QEMUFile *f, void *opaque, int version_id)
+{
+    PVRDMADev *dev = PVRDMA_DEV(opaque);
+    PCIDevice *pci_dev = PCI_DEVICE(dev);
+
+    // Remap DSR
+    dev->dsr_info.dma = qemu_get_be64(f);
+    dev->dsr_info.dsr = rdma_pci_dma_map(pci_dev, dev->dsr_info.dma,
+                                    sizeof(struct 
pvrdma_device_shared_region));
+    if (!dev->dsr_info.dsr) {
+        rdma_error_report("Failed to map to DSR");
+        return -1;
+    }
+    qemu_log("pvrdma_load: successfully remapped to DSR\n");
+
+    // Remap cmd slot
+    dev->dsr_info.dsr->cmd_slot_dma = qemu_get_be64(f);
+    dev->dsr_info.req = rdma_pci_dma_map(pci_dev, 
dev->dsr_info.dsr->cmd_slot_dma,
+                                     sizeof(union pvrdma_cmd_req));
+    if (!dev->dsr_info.req) {
+        rdma_error_report("Failed to map to command slot address");
+        return -1;
+    }
+    qemu_log("pvrdma_load: successfully remapped to cmd slot\n");
+
+    // Remap rsp slot
+    dev->dsr_info.dsr->resp_slot_dma = qemu_get_be64(f);
+    dev->dsr_info.rsp = rdma_pci_dma_map(pci_dev, 
dev->dsr_info.dsr->resp_slot_dma,
+                                     sizeof(union pvrdma_cmd_resp));
+    if (!dev->dsr_info.rsp) {
+        rdma_error_report("Failed to map to response slot address");
+        return -1;
+    }
+    qemu_log("pvrdma_load: successfully remapped to rsp slot\n");
+
+    return 0;
+}
+
+static SaveVMHandlers savevm_pvrdma = {
+    .save_state = pvrdma_save,
+    .load_state = pvrdma_load,
+};
+
 static void pvrdma_realize(PCIDevice *pdev, Error **errp)
 {
     int rc = 0;
+    DeviceState *s = DEVICE(pdev);
     PVRDMADev *dev = PVRDMA_DEV(pdev);
     Object *memdev_root;
     bool ram_shared = false;
@@ -666,6 +720,8 @@ static void pvrdma_realize(PCIDevice *pdev, Error **errp)
     dev->shutdown_notifier.notify = pvrdma_shutdown_notifier;
     qemu_register_shutdown_notifier(&dev->shutdown_notifier);
 
+    register_savevm_live(s, "pvrdma", -1, 1, &savevm_pvrdma, dev);
+
 out:
     if (rc) {
         pvrdma_fini(pdev);
-- 
2.21.0