[PATCH 04/15] pcie: Add callback preceding SR-IOV VFs update

[Lukasz Maniak <lukasz.maniak@linux.intel.com>]

PCIe devices implementing SR-IOV may need to perform certain actions
before the VFs are unrealized or vice versa.

Signed-off-by: Lukasz Maniak <lukasz.maniak@linux.intel.com>
---
 docs/pcie_sriov.txt         |  2 +-
 hw/pci/pcie_sriov.c         | 14 +++++++++++++-
 include/hw/pci/pcie_sriov.h |  8 +++++++-
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/docs/pcie_sriov.txt b/docs/pcie_sriov.txt
index f5e891e1d4..63ca1a7b8e 100644
--- a/docs/pcie_sriov.txt
+++ b/docs/pcie_sriov.txt
@@ -57,7 +57,7 @@ setting up a BAR for a VF.
       /* Add and initialize the SR/IOV capability */
       pcie_sriov_pf_init(d, 0x200, "your_virtual_dev",
                        vf_devid, initial_vfs, total_vfs,
-                       fun_offset, stride);
+                       fun_offset, stride, pre_vfs_update_cb);
 
       /* Set up individual VF BARs (parameters as for normal BARs) */
       pcie_sriov_pf_init_vf_bar( ... )
diff --git a/hw/pci/pcie_sriov.c b/hw/pci/pcie_sriov.c
index 501a1ff433..cac2aee061 100644
--- a/hw/pci/pcie_sriov.c
+++ b/hw/pci/pcie_sriov.c
@@ -30,7 +30,8 @@ static void unregister_vfs(PCIDevice *dev);
 void pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
                         const char *vfname, uint16_t vf_dev_id,
                         uint16_t init_vfs, uint16_t total_vfs,
-                        uint16_t vf_offset, uint16_t vf_stride)
+                        uint16_t vf_offset, uint16_t vf_stride,
+                        SriovVfsUpdate pre_vfs_update)
 {
     uint8_t *cfg = dev->config + offset;
     uint8_t *wmask;
@@ -41,6 +42,7 @@ void pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
     dev->exp.sriov_pf.num_vfs = 0;
     dev->exp.sriov_pf.vfname = g_strdup(vfname);
     dev->exp.sriov_pf.vf = NULL;
+    dev->exp.sriov_pf.pre_vfs_update = pre_vfs_update;
 
     pci_set_word(cfg + PCI_SRIOV_VF_OFFSET, vf_offset);
     pci_set_word(cfg + PCI_SRIOV_VF_STRIDE, vf_stride);
@@ -180,6 +182,11 @@ static void register_vfs(PCIDevice *dev)
     assert(dev->exp.sriov_pf.vf);
 
     trace_sriov_register_vfs(SRIOV_ID(dev), num_vfs);
+
+    if (dev->exp.sriov_pf.pre_vfs_update) {
+        dev->exp.sriov_pf.pre_vfs_update(dev, dev->exp.sriov_pf.num_vfs, num_vfs);
+    }
+
     for (i = 0; i < num_vfs; i++) {
         dev->exp.sriov_pf.vf[i] = register_vf(dev, devfn, dev->exp.sriov_pf.vfname, i);
         if (!dev->exp.sriov_pf.vf[i]) {
@@ -198,6 +205,11 @@ static void unregister_vfs(PCIDevice *dev)
     uint16_t i;
 
     trace_sriov_unregister_vfs(SRIOV_ID(dev), num_vfs);
+
+    if (dev->exp.sriov_pf.pre_vfs_update) {
+        dev->exp.sriov_pf.pre_vfs_update(dev, dev->exp.sriov_pf.num_vfs, 0);
+    }
+
     for (i = 0; i < num_vfs; i++) {
         PCIDevice *vf = dev->exp.sriov_pf.vf[i];
         object_property_set_bool(OBJECT(vf), "realized", false, &local_err);
diff --git a/include/hw/pci/pcie_sriov.h b/include/hw/pci/pcie_sriov.h
index 0974f00054..9ab48b79c0 100644
--- a/include/hw/pci/pcie_sriov.h
+++ b/include/hw/pci/pcie_sriov.h
@@ -13,11 +13,16 @@
 #ifndef QEMU_PCIE_SRIOV_H
 #define QEMU_PCIE_SRIOV_H
 
+typedef void (*SriovVfsUpdate)(PCIDevice *dev, uint16_t prev_num_vfs,
+                               uint16_t num_vfs);
+
 struct PCIESriovPF {
     uint16_t num_vfs;           /* Number of virtual functions created */
     uint8_t vf_bar_type[PCI_NUM_REGIONS];  /* Store type for each VF bar */
     const char *vfname;         /* Reference to the device type used for the VFs */
     PCIDevice **vf;             /* Pointer to an array of num_vfs VF devices */
+
+    SriovVfsUpdate pre_vfs_update;  /* Callback preceding VFs count change */
 };
 
 struct PCIESriovVF {
@@ -28,7 +33,8 @@ struct PCIESriovVF {
 void pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
                         const char *vfname, uint16_t vf_dev_id,
                         uint16_t init_vfs, uint16_t total_vfs,
-                        uint16_t vf_offset, uint16_t vf_stride);
+                        uint16_t vf_offset, uint16_t vf_stride,
+                        SriovVfsUpdate pre_vfs_update);
 void pcie_sriov_pf_exit(PCIDevice *dev);
 
 /* Set up a VF bar in the SR/IOV bar area */
-- 
2.25.1