1 files changed, 65 insertions, 1 deletions

diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
index 4b2bdd94b3..156051e6e9 100644
--- a/hw/s390x/s390-pci-bus.c
+++ b/hw/s390x/s390-pci-bus.c
@@ -16,6 +16,7 @@
 #include "qapi/visitor.h"
 #include "hw/s390x/s390-pci-bus.h"
 #include "hw/s390x/s390-pci-inst.h"
+#include "hw/s390x/s390-pci-kvm.h"
 #include "hw/s390x/s390-pci-vfio.h"
 #include "hw/pci/pci_bus.h"
 #include "hw/qdev-properties.h"
@@ -971,12 +972,51 @@ static void s390_pci_update_subordinate(PCIDevice *dev, uint32_t nr)
     }
 }
 
+static int s390_pci_interp_plug(S390pciState *s, S390PCIBusDevice *pbdev)
+{
+    uint32_t idx, fh;
+
+    if (!s390_pci_get_host_fh(pbdev, &fh)) {
+        return -EPERM;
+    }
+
+    /*
+     * The host device is already in an enabled state, but we always present
+     * the initial device state to the guest as disabled (ZPCI_FS_DISABLED).
+     * Therefore, mask off the enable bit from the passthrough handle until
+     * the guest issues a CLP SET PCI FN later to enable the device.
+     */
+    pbdev->fh = fh & ~FH_MASK_ENABLE;
+
+    /* Next, see if the idx is already in-use */
+    idx = pbdev->fh & FH_MASK_INDEX;
+    if (pbdev->idx != idx) {
+        if (s390_pci_find_dev_by_idx(s, idx)) {
+            return -EINVAL;
+        }
+        /*
+         * Update the idx entry with the passed through idx
+         * If the relinquished idx is lower than next_idx, use it
+         * to replace next_idx
+         */
+        g_hash_table_remove(s->zpci_table, &pbdev->idx);
+        if (idx < s->next_idx) {
+            s->next_idx = idx;
+        }
+        pbdev->idx = idx;
+        g_hash_table_insert(s->zpci_table, &pbdev->idx, pbdev);
+    }
+
+    return 0;
+}
+
 static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
                               Error **errp)
 {
     S390pciState *s = S390_PCI_HOST_BRIDGE(hotplug_dev);
     PCIDevice *pdev = NULL;
     S390PCIBusDevice *pbdev = NULL;
+    int rc;
 
     if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_BRIDGE)) {
         PCIBridge *pb = PCI_BRIDGE(dev);
@@ -1022,12 +1062,35 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
         set_pbdev_info(pbdev);
 
         if (object_dynamic_cast(OBJECT(dev), "vfio-pci")) {
-            pbdev->fh |= FH_SHM_VFIO;
+            /*
+             * By default, interpretation is always requested; if the available
+             * facilities indicate it is not available, fallback to the
+             * interception model.
+             */
+            if (pbdev->interp) {
+                if (s390_pci_kvm_interp_allowed()) {
+                    rc = s390_pci_interp_plug(s, pbdev);
+                    if (rc) {
+                        error_setg(errp, "Plug failed for zPCI device in "
+                                   "interpretation mode: %d", rc);
+                        return;
+                    }
+                } else {
+                    DPRINTF("zPCI interpretation facilities missing.\n");
+                    pbdev->interp = false;
+                }
+            }
             pbdev->iommu->dma_limit = s390_pci_start_dma_count(s, pbdev);
             /* Fill in CLP information passed via the vfio region */
             s390_pci_get_clp_info(pbdev);
+            if (!pbdev->interp) {
+                /* Do vfio passthrough but intercept for I/O */
+                pbdev->fh |= FH_SHM_VFIO;
+            }
         } else {
             pbdev->fh |= FH_SHM_EMUL;
+            /* Always intercept emulated devices */
+            pbdev->interp = false;
         }
 
         if (s390_pci_msix_init(pbdev)) {
@@ -1360,6 +1423,7 @@ static Property s390_pci_device_properties[] = {
     DEFINE_PROP_UINT16("uid", S390PCIBusDevice, uid, UID_UNDEFINED),
     DEFINE_PROP_S390_PCI_FID("fid", S390PCIBusDevice, fid),
     DEFINE_PROP_STRING("target", S390PCIBusDevice, target),
+    DEFINE_PROP_BOOL("interpret", S390PCIBusDevice, interp, true),
     DEFINE_PROP_END_OF_LIST(),
 };