[PATCH v26 03/17] vfio: Add save and load functions for VFIO PCI devices

[Kirti Wankhede]

These functions save and restore PCI device specific data - config
space of PCI device.
Used VMStateDescription to save and restore interrupt state.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
---
 hw/vfio/pci.c                 | 134 ++++++++++++++++++++++++++++++++++++++++++
 hw/vfio/pci.h                 |   1 +
 include/hw/vfio/vfio-common.h |   2 +
 3 files changed, 137 insertions(+)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index bffd5bfe3b78..9968cc553391 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -41,6 +41,7 @@
 #include "trace.h"
 #include "qapi/error.h"
 #include "migration/blocker.h"
+#include "migration/qemu-file.h"
 
 #define TYPE_VFIO_PCI_NOHOTPLUG "vfio-pci-nohotplug"
 
@@ -2401,11 +2402,142 @@ static Object *vfio_pci_get_object(VFIODevice 
*vbasedev)
     return OBJECT(vdev);
 }
 
+static int vfio_get_pci_irq_state(QEMUFile *f, void *pv, size_t size,
+                             const VMStateField *field)
+{
+    VFIOPCIDevice *vdev = container_of(pv, VFIOPCIDevice, vbasedev);
+    PCIDevice *pdev = &vdev->pdev;
+    uint32_t interrupt_type;
+
+    interrupt_type = qemu_get_be32(f);
+
+    if (interrupt_type == VFIO_INT_MSI) {
+        uint32_t msi_flags, msi_addr_lo, msi_addr_hi = 0, msi_data;
+        bool msi_64bit;
+
+        /* restore msi configuration */
+        msi_flags = pci_default_read_config(pdev,
+                                            pdev->msi_cap + PCI_MSI_FLAGS, 2);
+        msi_64bit = (msi_flags & PCI_MSI_FLAGS_64BIT);
+
+        vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_FLAGS,
+                              msi_flags & ~PCI_MSI_FLAGS_ENABLE, 2);
+
+        msi_addr_lo = pci_default_read_config(pdev,
+                                        pdev->msi_cap + PCI_MSI_ADDRESS_LO, 4);
+        vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO,
+                              msi_addr_lo, 4);
+
+        if (msi_64bit) {
+            msi_addr_hi = pci_default_read_config(pdev,
+                                        pdev->msi_cap + PCI_MSI_ADDRESS_HI, 4);
+            vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI,
+                                  msi_addr_hi, 4);
+        }
+
+        msi_data = pci_default_read_config(pdev,
+                pdev->msi_cap + (msi_64bit ? PCI_MSI_DATA_64 : 
PCI_MSI_DATA_32),
+                2);
+
+        vfio_pci_write_config(pdev,
+                pdev->msi_cap + (msi_64bit ? PCI_MSI_DATA_64 : 
PCI_MSI_DATA_32),
+                msi_data, 2);
+
+        vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_FLAGS,
+                              msi_flags | PCI_MSI_FLAGS_ENABLE, 2);
+    } else if (interrupt_type == VFIO_INT_MSIX) {
+        uint16_t offset;
+
+        msix_load(pdev, f);
+        offset = pci_default_read_config(pdev,
+                                       pdev->msix_cap + PCI_MSIX_FLAGS + 1, 2);
+        /* load enable bit and maskall bit */
+        vfio_pci_write_config(pdev, pdev->msix_cap + PCI_MSIX_FLAGS + 1,
+                              offset, 2);
+    }
+    return 0;
+}
+
+static int vfio_put_pci_irq_state(QEMUFile *f, void *pv, size_t size,
+                             const VMStateField *field, QJSON *vmdesc)
+{
+    VFIOPCIDevice *vdev = container_of(pv, VFIOPCIDevice, vbasedev);
+    PCIDevice *pdev = &vdev->pdev;
+
+    qemu_put_be32(f, vdev->interrupt);
+    if (vdev->interrupt == VFIO_INT_MSIX) {
+        msix_save(pdev, f);
+    }
+
+    return 0;
+}
+
+static const VMStateInfo vmstate_info_vfio_pci_irq_state = {
+    .name = "VFIO PCI irq state",
+    .get  = vfio_get_pci_irq_state,
+    .put  = vfio_put_pci_irq_state,
+};
+
+const VMStateDescription vmstate_vfio_pci_config = {
+    .name = "VFIOPCIDevice",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_INT32_POSITIVE_LE(version_id, VFIOPCIDevice),
+        VMSTATE_BUFFER_UNSAFE_INFO(interrupt, VFIOPCIDevice, 1,
+                                   vmstate_info_vfio_pci_irq_state,
+                                   sizeof(int32_t)),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f)
+{
+    VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
+    PCIDevice *pdev = &vdev->pdev;
+
+
+    pci_device_save(pdev, f);
+    vmstate_save_state(f, &vmstate_vfio_pci_config, vbasedev, NULL);
+}
+
+static int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
+{
+    VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
+    PCIDevice *pdev = &vdev->pdev;
+    uint16_t pci_cmd;
+    int ret, i;
+
+    ret = pci_device_load(pdev, f);
+    if (ret) {
+        return ret;
+    }
+
+    /* retore pci bar configuration */
+    pci_cmd = pci_default_read_config(pdev, PCI_COMMAND, 2);
+    vfio_pci_write_config(pdev, PCI_COMMAND,
+                        pci_cmd & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY), 2);
+    for (i = 0; i < PCI_ROM_SLOT; i++) {
+        uint32_t bar = pci_default_read_config(pdev,
+                                               PCI_BASE_ADDRESS_0 + i * 4, 4);
+
+        vfio_pci_write_config(pdev, PCI_BASE_ADDRESS_0 + i * 4, bar, 4);
+    }
+
+    ret = vmstate_load_state(f, &vmstate_vfio_pci_config, vbasedev,
+                             vdev->version_id);
+
+    vfio_pci_write_config(pdev, PCI_COMMAND, pci_cmd, 2);
+    return ret;
+}
+
 static VFIODeviceOps vfio_pci_ops = {
     .vfio_compute_needs_reset = vfio_pci_compute_needs_reset,
     .vfio_hot_reset_multi = vfio_pci_hot_reset_multi,
     .vfio_eoi = vfio_intx_eoi,
     .vfio_get_object = vfio_pci_get_object,
+    .vfio_save_config = vfio_pci_save_config,
+    .vfio_load_config = vfio_pci_load_config,
 };
 
 int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
@@ -2755,6 +2887,8 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
     vdev->vbasedev.ops = &vfio_pci_ops;
     vdev->vbasedev.type = VFIO_DEVICE_TYPE_PCI;
     vdev->vbasedev.dev = DEVICE(vdev);
+    vdev->vbasedev.device_state = 0;
+    vdev->version_id = 1;
 
     tmp = g_strdup_printf("%s/iommu_group", vdev->vbasedev.sysfsdev);
     len = readlink(tmp, group_path, sizeof(group_path));
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index bce71a9ac93f..9f46af7e153f 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -156,6 +156,7 @@ struct VFIOPCIDevice {
     uint32_t display_yres;
     int32_t bootindex;
     uint32_t igd_gms;
+    int32_t version_id;     /* Version id needed for VMState */
     OffAutoPCIBAR msix_relo;
     uint8_t pm_cap;
     uint8_t nv_gpudirect_clique;
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index fe99c36a693a..ba6169cd926e 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -120,6 +120,8 @@ struct VFIODeviceOps {
     int (*vfio_hot_reset_multi)(VFIODevice *vdev);
     void (*vfio_eoi)(VFIODevice *vdev);
     Object *(*vfio_get_object)(VFIODevice *vdev);
+    void (*vfio_save_config)(VFIODevice *vdev, QEMUFile *f);
+    int (*vfio_load_config)(VFIODevice *vdev, QEMUFile *f);
 };
 
 typedef struct VFIOGroup {
-- 
2.7.0