[Qemu-devel] [PATCH v8 08/19] hw/vfio/pci: split vfio_get_device

[Eric Auger <eric.auger@linaro.org>]

vfio_get_device now takes a VFIODevice as argument. The function is split
into 2 parts: vfio_get_device which is generic and vfio_populate_device
which is bus specific.

3 new fields are introduced in VFIODevice to store dev_info.

vfio_put_base_device is created.

---

v5->v6:
- simplifies the split for vfio_get_device:
  vfio_check_device, vfio_populate_regions, vfio_populate_interrupts
  are now gathered into a unique specialization function dubbed
  vfio_populate_device

v4->v5:
- cleanup up of error handling and get/put operations in
  vfio_check_device, vfio_populate_regions, vfio_populate_interrupts and
  vfio_get_device.
  - correct misuse of errno
  - vfio_populate_regions always returns 0
  - VFIODevice .name deallocation done in vfio_put_device instead of
    vfio_put_base_device
  - vfio_put_base_device done at vfio_get_device level.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
---
 hw/vfio/pci.c | 130 +++++++++++++++++++++++++++++++++++-----------------------
 trace-events  |  10 ++---
 2 files changed, 83 insertions(+), 57 deletions(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 10c1697..60ff22b 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -204,12 +204,16 @@ typedef struct VFIODevice {
     bool reset_works;
     bool needs_reset;
     VFIODeviceOps *ops;
+    unsigned int num_irqs;
+    unsigned int num_regions;
+    unsigned int flags;
 } VFIODevice;
 
 struct VFIODeviceOps {
     void (*vfio_compute_needs_reset)(VFIODevice *vdev);
     int (*vfio_hot_reset_multi)(VFIODevice *vdev);
     void (*vfio_eoi)(VFIODevice *vdev);
+    int (*vfio_populate_device)(VFIODevice *vdev);
 };
 
 typedef struct VFIOPCIDevice {
@@ -296,6 +300,8 @@ static uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len);
 static void vfio_pci_write_config(PCIDevice *pdev, uint32_t addr,
                                   uint32_t val, int len);
 static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled);
+static void vfio_put_base_device(VFIODevice *vbasedev);
+static int vfio_populate_device(VFIODevice *vbasedev);
 
 /*
  * Common VFIO interrupt disable
@@ -3610,6 +3616,7 @@ 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_eoi,
+    .vfio_populate_device = vfio_populate_device,
 };
 
 static void vfio_reset_handler(void *opaque)
@@ -3951,70 +3958,45 @@ static void vfio_put_group(VFIOGroup *group)
     }
 }
 
-static int vfio_get_device(VFIOGroup *group, const char *name,
-                           VFIOPCIDevice *vdev)
+static int vfio_populate_device(VFIODevice *vbasedev)
 {
-    struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
+    VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
     struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
     struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
-    int ret, i;
-
-    ret = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
-    if (ret < 0) {
-        error_report("vfio: error getting device %s from group %d: %m",
-                     name, group->groupid);
-        error_printf("Verify all devices in group %d are bound to vfio-pci "
-                     "or pci-stub and not already in use\n", group->groupid);
-        return ret;
-    }
-
-    vdev->vbasedev.fd = ret;
-    vdev->vbasedev.group = group;
-    QLIST_INSERT_HEAD(&group->device_list, &vdev->vbasedev, next);
+    int i, ret = -1;
 
     /* Sanity check device */
-    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_INFO, &dev_info);
-    if (ret) {
-        error_report("vfio: error getting device info: %m");
-        goto error;
-    }
-
-    trace_vfio_get_device_irq(name, dev_info.flags,
-                              dev_info.num_regions, dev_info.num_irqs);
-
-    if (!(dev_info.flags & VFIO_DEVICE_FLAGS_PCI)) {
+    if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PCI)) {
         error_report("vfio: Um, this isn't a PCI device");
         goto error;
     }
 
-    vdev->vbasedev.reset_works = !!(dev_info.flags & VFIO_DEVICE_FLAGS_RESET);
-
-    if (dev_info.num_regions < VFIO_PCI_CONFIG_REGION_INDEX + 1) {
+    if (vbasedev->num_regions < VFIO_PCI_CONFIG_REGION_INDEX + 1) {
         error_report("vfio: unexpected number of io regions %u",
-                     dev_info.num_regions);
+                     vbasedev->num_regions);
         goto error;
     }
 
-    if (dev_info.num_irqs < VFIO_PCI_MSIX_IRQ_INDEX + 1) {
-        error_report("vfio: unexpected number of irqs %u", dev_info.num_irqs);
+    if (vbasedev->num_irqs < VFIO_PCI_MSIX_IRQ_INDEX + 1) {
+        error_report("vfio: unexpected number of irqs %u", vbasedev->num_irqs);
         goto error;
     }
 
     for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
         reg_info.index = i;
 
-        ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
+        ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
         if (ret) {
             error_report("vfio: Error getting region %d info: %m", i);
             goto error;
         }
 
-        trace_vfio_get_device_region(name, i,
-                                     (unsigned long)reg_info.size,
-                                     (unsigned long)reg_info.offset,
-                                     (unsigned long)reg_info.flags);
+        trace_vfio_populate_device_region(vbasedev->name, i,
+                                          (unsigned long)reg_info.size,
+                                          (unsigned long)reg_info.offset,
+                                          (unsigned long)reg_info.flags);
 
-        vdev->bars[i].region.vbasedev = &vdev->vbasedev;
+        vdev->bars[i].region.vbasedev = vbasedev;
         vdev->bars[i].region.flags = reg_info.flags;
         vdev->bars[i].region.size = reg_info.size;
         vdev->bars[i].region.fd_offset = reg_info.offset;
@@ -4030,9 +4012,10 @@ static int vfio_get_device(VFIOGroup *group, const char *name,
         goto error;
     }
 
-    trace_vfio_get_device_config(name, (unsigned long)reg_info.size,
-                                 (unsigned long)reg_info.offset,
-                                 (unsigned long)reg_info.flags);
+    trace_vfio_populate_device_config(vdev->vbasedev.name,
+                                      (unsigned long)reg_info.size,
+                                      (unsigned long)reg_info.offset,
+                                      (unsigned long)reg_info.flags);
 
     vdev->config_size = reg_info.size;
     if (vdev->config_size == PCI_CONFIG_SPACE_SIZE) {
@@ -4041,7 +4024,7 @@ static int vfio_get_device(VFIOGroup *group, const char *name,
     vdev->config_offset = reg_info.offset;
 
     if ((vdev->features & VFIO_FEATURE_ENABLE_VGA) &&
-        dev_info.num_regions > VFIO_PCI_VGA_REGION_INDEX) {
+        vbasedev->num_regions > VFIO_PCI_VGA_REGION_INDEX) {
         struct vfio_region_info vga_info = {
             .argsz = sizeof(vga_info),
             .index = VFIO_PCI_VGA_REGION_INDEX,
@@ -4085,7 +4068,7 @@ static int vfio_get_device(VFIOGroup *group, const char *name,
     ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
     if (ret) {
         /* This can fail for an old kernel or legacy PCI dev */
-        trace_vfio_get_device_get_irq_info_failure();
+        trace_vfio_populate_device_get_irq_info_failure();
         ret = 0;
     } else if (irq_info.count == 1) {
         vdev->pci_aer = true;
@@ -4097,25 +4080,68 @@ static int vfio_get_device(VFIOGroup *group, const char *name,
     }
 
 error:
+    return ret;
+}
+
+static int vfio_get_device(VFIOGroup *group, const char *name,
+                           VFIODevice *vbasedev)
+{
+    struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
+    int ret;
+
+    ret = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
+    if (ret < 0) {
+        error_report("vfio: error getting device %s from group %d: %m",
+                     name, group->groupid);
+        error_printf("Verify all devices in group %d are bound to vfio-<bus> "
+                     "or pci-stub and not already in use\n", group->groupid);
+        return ret;
+    }
+
+    vbasedev->fd = ret;
+    vbasedev->group = group;
+    QLIST_INSERT_HEAD(&group->device_list, vbasedev, next);
+
+    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_INFO, &dev_info);
+    if (ret) {
+        error_report("vfio: error getting device info: %m");
+        goto error;
+    }
+
+    vbasedev->num_irqs = dev_info.num_irqs;
+    vbasedev->num_regions = dev_info.num_regions;
+    vbasedev->flags = dev_info.flags;
+
+    trace_vfio_get_device(name, dev_info.flags,
+                          dev_info.num_regions, dev_info.num_irqs);
+
+    vbasedev->reset_works = !!(dev_info.flags & VFIO_DEVICE_FLAGS_RESET);
+
+    ret = vbasedev->ops->vfio_populate_device(vbasedev);
+
+error:
     if (ret) {
-        QLIST_REMOVE(&vdev->vbasedev, next);
-        vdev->vbasedev.group = NULL;
-        close(vdev->vbasedev.fd);
+        vfio_put_base_device(vbasedev);
     }
     return ret;
 }
 
+void vfio_put_base_device(VFIODevice *vbasedev)
+{
+    QLIST_REMOVE(vbasedev, next);
+    vbasedev->group = NULL;
+    trace_vfio_put_base_device(vbasedev->fd);
+    close(vbasedev->fd);
+}
+
 static void vfio_put_device(VFIOPCIDevice *vdev)
 {
-    QLIST_REMOVE(&vdev->vbasedev, next);
-    vdev->vbasedev.group = NULL;
-    trace_vfio_put_device(vdev->vbasedev.fd);
-    close(vdev->vbasedev.fd);
     g_free(vdev->vbasedev.name);
     if (vdev->msix) {
         g_free(vdev->msix);
         vdev->msix = NULL;
     }
+    vfio_put_base_device(&vdev->vbasedev);
 }
 
 static void vfio_err_notifier_handler(void *opaque)
@@ -4288,7 +4314,7 @@ static int vfio_initfn(PCIDevice *pdev)
         }
     }
 
-    ret = vfio_get_device(group, path, vdev);
+    ret = vfio_get_device(group, path, &vdev->vbasedev);
     if (ret) {
         error_report("vfio: failed to get device %s", path);
         vfio_put_group(group);
diff --git a/trace-events b/trace-events
index 7a93178..55a559b 100644
--- a/trace-events
+++ b/trace-events
@@ -1403,10 +1403,10 @@ vfio_pci_hot_reset(int domain, int bus, int slot, int fn, const char *type) " (%
 vfio_pci_hot_reset_has_dep_devices(int domain, int bus, int slot, int fn) "%04x:%02x:%02x.%x: hot reset dependent devices:"
 vfio_pci_hot_reset_dep_devices(int domain, int bus, int slot, int function, int group_id) "\t%04x:%02x:%02x.%x group %d"
 vfio_pci_hot_reset_result(int domain, int bus, int slot, int fn, const char *result) "%04x:%02x:%02x.%x hot reset: %s"
-vfio_get_device_region(const char *region_name, int index, unsigned long size, unsigned long offset, unsigned long flags) "Device %s region %d:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
-vfio_get_device_config(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device %s config:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
-vfio_get_device_get_irq_info_failure(void) "VFIO_DEVICE_GET_IRQ_INFO failure: %m"
-vfio_get_device_irq(const char *name, unsigned flags, unsigned num_regions, unsigned num_irqs) "Device %s flags: %u, regions: %u, irgs: %u"
+vfio_populate_device_region(const char *region_name, int index, unsigned long size, unsigned long offset, unsigned long flags) "Device %s region %d:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
+vfio_populate_device_config(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device %s config:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
+vfio_populate_device_get_irq_info_failure(void) "VFIO_DEVICE_GET_IRQ_INFO failure: %m"
+vfio_get_device(const char *name, unsigned flags, unsigned num_regions, unsigned num_irqs) "Device %s flags: %u, regions: %u, irgs: %u"
 vfio_initfn(int domain, int bus, int slot, int fn, int group_id) " (%04x:%02x:%02x.%x) group %d"
 vfio_pci_reset(int domain, int bus, int slot, int fn) " (%04x:%02x:%02x.%x)"
 vfio_pci_reset_flr(int domain, int bus, int slot, int fn) "%04x:%02x:%02x.%x FLR/VFIO_DEVICE_RESET"
@@ -1422,7 +1422,7 @@ vfio_listener_region_del_skip(uint64_t start, uint64_t end) "SKIPPING region_del
 vfio_listener_region_del(uint64_t start, uint64_t end) "region_del %"PRIx64" - %"PRIx64
 vfio_disconnect_container(int fd) "close container->fd=%d"
 vfio_put_group(int fd) "close group->fd=%d"
-vfio_put_device(int fd) "close vdev->fd=%d"
+vfio_put_base_device(int fd) "close vdev->fd=%d"
 
 #hw/acpi/memory_hotplug.c
 mhp_acpi_invalid_slot_selected(uint32_t slot) "0x%"PRIx32
-- 
1.8.3.2