[RFC v9 28/29] pci: Add return_page_response pci ops

[Eric Auger <eric.auger@redhat.com>]

Add a new PCI operation that allows to return page responses
to registered VFIO devices

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 include/hw/iommu/iommu.h |  8 ++++++++
 include/hw/pci/pci.h     |  4 ++++
 hw/pci/pci.c             | 16 ++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/include/hw/iommu/iommu.h b/include/hw/iommu/iommu.h
index 12092bda7b..5890f095b1 100644
--- a/include/hw/iommu/iommu.h
+++ b/include/hw/iommu/iommu.h
@@ -24,5 +24,13 @@ typedef struct IOMMUConfig {
           };
 } IOMMUConfig;
 
+typedef struct IOMMUPageResponse {
+    union {
+#ifdef __linux__
+        struct iommu_page_response resp;
+#endif
+          };
+} IOMMUPageResponse;
+
 
 #endif /* QEMU_HW_IOMMU_IOMMU_H */
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 1f73c04975..9bc0919352 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -268,6 +268,8 @@ typedef struct PCIReqIDCache PCIReqIDCache;
 
 struct PCIPASIDOps {
     int (*set_pasid_table)(PCIBus *bus, int32_t devfn, IOMMUConfig *config);
+    int (*return_page_response)(PCIBus *bus, int32_t devfn,
+                                IOMMUPageResponse *resp);
 };
 typedef struct PCIPASIDOps PCIPASIDOps;
 
@@ -501,6 +503,8 @@ void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque);
 void pci_setup_pasid_ops(PCIDevice *dev, PCIPASIDOps *ops);
 bool pci_device_is_pasid_ops_set(PCIBus *bus, int32_t devfn);
 int pci_device_set_pasid_table(PCIBus *bus, int32_t devfn, IOMMUConfig *config);
+int pci_device_return_page_response(PCIBus *bus, int32_t devfn,
+                                    IOMMUPageResponse *resp);
 
 static inline void
 pci_set_byte(uint8_t *config, uint8_t val)
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 114855a0ac..18d84ff42e 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2765,6 +2765,22 @@ int pci_device_set_pasid_table(PCIBus *bus, int32_t devfn,
     return -ENOENT;
 }
 
+int pci_device_return_page_response(PCIBus *bus, int32_t devfn,
+                                    IOMMUPageResponse *resp)
+{
+    PCIDevice *dev;
+
+    if (!bus) {
+        return -EINVAL;
+    }
+
+    dev = bus->devices[devfn];
+    if (dev && dev->pasid_ops && dev->pasid_ops->return_page_response) {
+        return dev->pasid_ops->return_page_response(bus, devfn, resp);
+    }
+    return -ENOENT;
+}
+
 static void pci_dev_get_w64(PCIBus *b, PCIDevice *dev, void *opaque)
 {
     Range *range = opaque;
-- 
2.26.3