diff mbox series

[12/14] vfio: add region info cache

Message ID 20250409134814.478903-13-john.levon@nutanix.com (mailing list archive)
State New
Headers show
Series vfio: preparation for vfio-user | expand

Commit Message

John Levon April 9, 2025, 1:48 p.m. UTC 
Instead of requesting region information on demand with
VFIO_DEVICE_GET_REGION_INFO, maintain a cache: this will become
necessary for performance for vfio-user, where this call becomes a
message over the control socket, so is of higher overhead than the
traditional path.

We will also need it to generalize region accesses, as that means we
can't use ->config_offset for configuration space accesses, but must
look up the region offset (if relevant) each time.

Originally-by: John Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John Levon <john.levon@nutanix.com>
---
 hw/vfio/ccw.c                 |  5 -----
 hw/vfio/container.c           | 10 ++++++++++
 hw/vfio/device.c              | 31 +++++++++++++++++++++++++++----
 hw/vfio/igd.c                 |  8 ++++----
 hw/vfio/pci.c                 |  6 +++---
 hw/vfio/region.c              |  2 +-
 include/hw/vfio/vfio-device.h |  1 +
 7 files changed, 46 insertions(+), 17 deletions(-)
diff mbox series

Patch

diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index dac8769925..14dee7cd19 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -504,7 +504,6 @@  static bool vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
 
     vcdev->io_region_offset = info->offset;
     vcdev->io_region = g_malloc0(info->size);
-    g_free(info);
 
     /* check for the optional async command region */
     ret = vfio_device_get_region_info_type(vdev, VFIO_REGION_TYPE_CCW,
@@ -517,7 +516,6 @@  static bool vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
         }
         vcdev->async_cmd_region_offset = info->offset;
         vcdev->async_cmd_region = g_malloc0(info->size);
-        g_free(info);
     }
 
     ret = vfio_device_get_region_info_type(vdev, VFIO_REGION_TYPE_CCW,
@@ -530,7 +528,6 @@  static bool vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
         }
         vcdev->schib_region_offset = info->offset;
         vcdev->schib_region = g_malloc(info->size);
-        g_free(info);
     }
 
     ret = vfio_device_get_region_info_type(vdev, VFIO_REGION_TYPE_CCW,
@@ -544,7 +541,6 @@  static bool vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
         }
         vcdev->crw_region_offset = info->offset;
         vcdev->crw_region = g_malloc(info->size);
-        g_free(info);
     }
 
     return true;
@@ -554,7 +550,6 @@  out_err:
     g_free(vcdev->schib_region);
     g_free(vcdev->async_cmd_region);
     g_free(vcdev->io_region);
-    g_free(info);
     return false;
 }
 
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 37b1217fd8..61333d7fc4 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -857,6 +857,16 @@  static bool vfio_device_get(VFIOGroup *group, const char *name,
 
 static void vfio_device_put(VFIODevice *vbasedev)
 {
+    if (vbasedev->reginfo != NULL) {
+        int i;
+
+        for (i = 0; i < vbasedev->num_regions; i++) {
+            g_free(vbasedev->reginfo[i]);
+        }
+        g_free(vbasedev->reginfo);
+        vbasedev->reginfo = NULL;
+    }
+
     if (!vbasedev->group) {
         return;
     }
diff --git a/hw/vfio/device.c b/hw/vfio/device.c
index 2966171118..102fa5a9b4 100644
--- a/hw/vfio/device.c
+++ b/hw/vfio/device.c
@@ -205,6 +205,17 @@  int vfio_device_get_region_info(VFIODevice *vbasedev, int index,
 {
     size_t argsz = sizeof(struct vfio_region_info);
 
+    /* create region info cache */
+    if (vbasedev->reginfo == NULL) {
+        vbasedev->reginfo = g_new0(struct vfio_region_info *,
+                                   vbasedev->num_regions);
+    }
+    /* check cache */
+    if (vbasedev->reginfo[index] != NULL) {
+        *info = vbasedev->reginfo[index];
+        return 0;
+    }
+
     *info = g_malloc0(argsz);
 
     (*info)->index = index;
@@ -224,6 +235,9 @@  retry:
         goto retry;
     }
 
+    /* fill cache */
+    vbasedev->reginfo[index] = *info;
+
     return 0;
 }
 
@@ -242,7 +256,6 @@  int vfio_device_get_region_info_type(VFIODevice *vbasedev, uint32_t type,
 
         hdr = vfio_get_region_info_cap(*info, VFIO_REGION_INFO_CAP_TYPE);
         if (!hdr) {
-            g_free(*info);
             continue;
         }
 
@@ -254,8 +267,6 @@  int vfio_device_get_region_info_type(VFIODevice *vbasedev, uint32_t type,
         if (cap_type->type == type && cap_type->subtype == subtype) {
             return 0;
         }
-
-        g_free(*info);
     }
 
     *info = NULL;
@@ -264,7 +275,7 @@  int vfio_device_get_region_info_type(VFIODevice *vbasedev, uint32_t type,
 
 bool vfio_device_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type)
 {
-    g_autofree struct vfio_region_info *info = NULL;
+    struct vfio_region_info *info = NULL;
     bool ret = false;
 
     if (!vfio_device_get_region_info(vbasedev, region, &info)) {
@@ -427,6 +438,16 @@  void vfio_device_detach(VFIODevice *vbasedev)
     VFIO_IOMMU_GET_CLASS(vbasedev->bcontainer)->detach_device(vbasedev);
 }
 
+static void vfio_device_get_all_region_info(VFIODevice *vbasedev)
+{
+    struct vfio_region_info *info;
+    int i;
+
+    for (i = 0; i < vbasedev->num_regions; i++) {
+        vfio_device_get_region_info(vbasedev, i, &info);
+    }
+}
+
 void vfio_device_prepare(VFIODevice *vbasedev, VFIOContainerBase *bcontainer,
                          struct vfio_device_info *info)
 {
@@ -439,4 +460,6 @@  void vfio_device_prepare(VFIODevice *vbasedev, VFIOContainerBase *bcontainer,
     QLIST_INSERT_HEAD(&bcontainer->device_list, vbasedev, container_next);
 
     QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);
+
+    vfio_device_get_all_region_info(vbasedev);
 }
diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index e1cba16399..d70da1ce38 100644
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -198,7 +198,7 @@  static bool vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
 
 static bool vfio_pci_igd_setup_opregion(VFIOPCIDevice *vdev, Error **errp)
 {
-    g_autofree struct vfio_region_info *opregion = NULL;
+    struct vfio_region_info *opregion = NULL;
     int ret;
 
     /* Hotplugging is not supported for opregion access */
@@ -361,8 +361,8 @@  static int vfio_pci_igd_lpc_init(VFIOPCIDevice *vdev,
 
 static bool vfio_pci_igd_setup_lpc_bridge(VFIOPCIDevice *vdev, Error **errp)
 {
-    g_autofree struct vfio_region_info *host = NULL;
-    g_autofree struct vfio_region_info *lpc = NULL;
+    struct vfio_region_info *host = NULL;
+    struct vfio_region_info *lpc = NULL;
     PCIDevice *lpc_bridge;
     int ret;
 
@@ -526,7 +526,7 @@  static bool vfio_pci_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp)
          * - OpRegion
          * - Same LPC bridge and Host bridge VID/DID/SVID/SSID as host
          */
-        g_autofree struct vfio_region_info *rom = NULL;
+        struct vfio_region_info *rom = NULL;
 
         legacy_mode_enabled = true;
         info_report("IGD legacy mode enabled, "
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index c3842d2f8d..b40d5abdfd 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -882,8 +882,8 @@  static void vfio_update_msi(VFIOPCIDevice *vdev)
 
 static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
 {
-    g_autofree struct vfio_region_info *reg_info = NULL;
     VFIODevice *vbasedev = &vdev->vbasedev;
+    struct vfio_region_info *reg_info = NULL;
     uint64_t size;
     off_t off = 0;
     ssize_t bytes;
@@ -2721,7 +2721,7 @@  static VFIODeviceOps vfio_pci_ops = {
 bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
 {
     VFIODevice *vbasedev = &vdev->vbasedev;
-    g_autofree struct vfio_region_info *reg_info = NULL;
+    struct vfio_region_info *reg_info = NULL;
     int ret;
 
     ret = vfio_device_get_region_info(vbasedev, VFIO_PCI_VGA_REGION_INDEX, &reg_info);
@@ -2786,7 +2786,7 @@  bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
 static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
 {
     VFIODevice *vbasedev = &vdev->vbasedev;
-    g_autofree struct vfio_region_info *reg_info = NULL;
+    struct vfio_region_info *reg_info = NULL;
     struct vfio_irq_info irq_info;
     int i, ret = -1;
 
diff --git a/hw/vfio/region.c b/hw/vfio/region.c
index 04bf9eb098..ef2630cac3 100644
--- a/hw/vfio/region.c
+++ b/hw/vfio/region.c
@@ -182,7 +182,7 @@  static int vfio_setup_region_sparse_mmaps(VFIORegion *region,
 int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
                       int index, const char *name)
 {
-    g_autofree struct vfio_region_info *info = NULL;
+    struct vfio_region_info *info = NULL;
     int ret;
 
     ret = vfio_device_get_region_info(vbasedev, index, &info);
diff --git a/include/hw/vfio/vfio-device.h b/include/hw/vfio/vfio-device.h
index 9522a09c48..967b07cd89 100644
--- a/include/hw/vfio/vfio-device.h
+++ b/include/hw/vfio/vfio-device.h
@@ -81,6 +81,7 @@  typedef struct VFIODevice {
     IOMMUFDBackend *iommufd;
     VFIOIOASHwpt *hwpt;
     QLIST_ENTRY(VFIODevice) hwpt_next;
+    struct vfio_region_info **reginfo;
 } VFIODevice;
 
 struct VFIODeviceOps {