[PATCH v2 7/9] s390x/pci: use I/O Address Translation assist when interpreting

[Matthew Rosato <mjrosato@xxxxxxxxxxxxx>]

Allow the underlying kvm host to handle the Refresh PCI Translation
instruction intercepts.

Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
---
 hw/s390x/s390-pci-bus.c          |  6 ++--
 hw/s390x/s390-pci-inst.c         | 51 ++++++++++++++++++++++++++++++--
 hw/s390x/s390-pci-vfio.c         | 27 +++++++++++++++++
 include/hw/s390x/s390-pci-inst.h |  2 +-
 include/hw/s390x/s390-pci-vfio.h | 10 +++++++
 5 files changed, 89 insertions(+), 7 deletions(-)

diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
index 6ee70446ca..49ae2fd0ea 100644
--- a/hw/s390x/s390-pci-bus.c
+++ b/hw/s390x/s390-pci-bus.c
@@ -196,7 +196,7 @@ void s390_pci_sclp_deconfigure(SCCB *sccb)
             pci_dereg_irqs(pbdev);
         }
         if (pbdev->iommu->enabled) {
-            pci_dereg_ioat(pbdev->iommu);
+            pci_dereg_ioat(pbdev);
         }
         pbdev->state = ZPCI_FS_STANDBY;
         rc = SCLP_RC_NORMAL_COMPLETION;
@@ -1262,7 +1262,7 @@ static void s390_pcihost_reset(DeviceState *dev)
                 pci_dereg_irqs(pbdev);
             }
             if (pbdev->iommu->enabled) {
-                pci_dereg_ioat(pbdev->iommu);
+                pci_dereg_ioat(pbdev);
             }
             pbdev->state = ZPCI_FS_STANDBY;
             s390_pci_perform_unplug(pbdev);
@@ -1403,7 +1403,7 @@ static void s390_pci_device_reset(DeviceState *dev)
         pci_dereg_irqs(pbdev);
     }
     if (pbdev->iommu->enabled) {
-        pci_dereg_ioat(pbdev->iommu);
+        pci_dereg_ioat(pbdev);
     }
 
     fmb_timer_free(pbdev);
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
index 121e07cc41..0fa18866c0 100644
--- a/hw/s390x/s390-pci-inst.c
+++ b/hw/s390x/s390-pci-inst.c
@@ -978,6 +978,24 @@ int pci_dereg_irqs(S390PCIBusDevice *pbdev)
     return 0;
 }
 
+static int reg_ioat_interp(S390PCIBusDevice *pbdev, uint64_t iota)
+{
+    int rc;
+
+    rc = s390_pci_probe_ioat(pbdev);
+    if (rc) {
+        return rc;
+    }
+
+    rc = s390_pci_set_ioat(pbdev, iota);
+    if (rc) {
+        return rc;
+    }
+
+    pbdev->iommu->enabled = true;
+    return 0;
+}
+
 static int reg_ioat(CPUS390XState *env, S390PCIBusDevice *pbdev, ZpciFib fib,
                     uintptr_t ra)
 {
@@ -995,6 +1013,16 @@ static int reg_ioat(CPUS390XState *env, S390PCIBusDevice *pbdev, ZpciFib fib,
         return -EINVAL;
     }
 
+    /* If this is an interpreted device, we must use the IOAT assist */
+    if (pbdev->interp) {
+        if (reg_ioat_interp(pbdev, g_iota)) {
+            error_report("failure starting ioat assist");
+            s390_program_interrupt(env, PGM_OPERAND, ra);
+            return -EINVAL;
+        }
+        return 0;
+    }
+
     /* currently we only support designation type 1 with translation */
     if (!(dt == ZPCI_IOTA_RTTO && t)) {
         error_report("unsupported ioat dt %d t %d", dt, t);
@@ -1011,8 +1039,25 @@ static int reg_ioat(CPUS390XState *env, S390PCIBusDevice *pbdev, ZpciFib fib,
     return 0;
 }
 
-void pci_dereg_ioat(S390PCIIOMMU *iommu)
+static void dereg_ioat_interp(S390PCIBusDevice *pbdev)
 {
+    if (s390_pci_probe_ioat(pbdev) != 0) {
+        return;
+    }
+
+    s390_pci_set_ioat(pbdev, 0);
+    pbdev->iommu->enabled = false;
+}
+
+void pci_dereg_ioat(S390PCIBusDevice *pbdev)
+{
+    S390PCIIOMMU *iommu = pbdev->iommu;
+
+    if (pbdev->interp) {
+        dereg_ioat_interp(pbdev);
+        return;
+    }
+
     s390_pci_iommu_disable(iommu);
     iommu->pba = 0;
     iommu->pal = 0;
@@ -1251,7 +1296,7 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
             cc = ZPCI_PCI_LS_ERR;
             s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
         } else {
-            pci_dereg_ioat(pbdev->iommu);
+            pci_dereg_ioat(pbdev);
         }
         break;
     case ZPCI_MOD_FC_REREG_IOAT:
@@ -1262,7 +1307,7 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
             cc = ZPCI_PCI_LS_ERR;
             s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
         } else {
-            pci_dereg_ioat(pbdev->iommu);
+            pci_dereg_ioat(pbdev);
             if (reg_ioat(env, pbdev, fib, ra)) {
                 cc = ZPCI_PCI_LS_ERR;
                 s390_set_status_code(env, r1, ZPCI_MOD_ST_INSUF_RES);
diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c
index 73f3b3ed19..4e3165bff5 100644
--- a/hw/s390x/s390-pci-vfio.c
+++ b/hw/s390x/s390-pci-vfio.c
@@ -228,6 +228,33 @@ int s390_pci_get_aif(S390PCIBusDevice *pbdev, bool enable, bool assist)
     return rc;
 }
 
+int s390_pci_probe_ioat(S390PCIBusDevice *pbdev)
+{
+    VFIOPCIDevice *vdev = VFIO_PCI(pbdev->pdev);
+    struct vfio_device_feature feat = {
+        .argsz = sizeof(struct vfio_device_feature),
+        .flags = VFIO_DEVICE_FEATURE_PROBE + VFIO_DEVICE_FEATURE_ZPCI_IOAT
+    };
+
+    return ioctl(vdev->vbasedev.fd, VFIO_DEVICE_FEATURE, &feat);
+}
+
+int s390_pci_set_ioat(S390PCIBusDevice *pbdev, uint64_t iota)
+{
+    VFIOPCIDevice *vdev = VFIO_PCI(pbdev->pdev);
+    struct vfio_device_zpci_ioat *data;
+    int size = sizeof(struct vfio_device_feature) + sizeof(*data);
+    g_autofree struct vfio_device_feature *feat = g_malloc0(size);
+
+    feat->argsz = size;
+    feat->flags = VFIO_DEVICE_FEATURE_SET + VFIO_DEVICE_FEATURE_ZPCI_IOAT;
+
+    data = (struct vfio_device_zpci_ioat *)&feat->data;
+    data->iota = iota;
+
+    return ioctl(vdev->vbasedev.fd, VFIO_DEVICE_FEATURE, feat);
+}
+
 static void s390_pci_read_base(S390PCIBusDevice *pbdev,
                                struct vfio_device_info *info)
 {
diff --git a/include/hw/s390x/s390-pci-inst.h b/include/hw/s390x/s390-pci-inst.h
index a55c448aad..13566fb7b4 100644
--- a/include/hw/s390x/s390-pci-inst.h
+++ b/include/hw/s390x/s390-pci-inst.h
@@ -99,7 +99,7 @@ typedef struct ZpciFib {
 } QEMU_PACKED ZpciFib;
 
 int pci_dereg_irqs(S390PCIBusDevice *pbdev);
-void pci_dereg_ioat(S390PCIIOMMU *iommu);
+void pci_dereg_ioat(S390PCIBusDevice *pbdev);
 int clp_service_call(S390CPU *cpu, uint8_t r2, uintptr_t ra);
 int pcilg_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra);
 int pcistg_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra);
diff --git a/include/hw/s390x/s390-pci-vfio.h b/include/hw/s390x/s390-pci-vfio.h
index 6cec38a863..e7a2d8ff77 100644
--- a/include/hw/s390x/s390-pci-vfio.h
+++ b/include/hw/s390x/s390-pci-vfio.h
@@ -28,6 +28,8 @@ int s390_pci_probe_aif(S390PCIBusDevice *pbdev);
 int s390_pci_set_aif(S390PCIBusDevice *pbdev, ZpciFib *fib, bool enable,
                      bool assist);
 int s390_pci_get_aif(S390PCIBusDevice *pbdev, bool enable, bool assist);
+int s390_pci_probe_ioat(S390PCIBusDevice *pbdev);
+int s390_pci_set_ioat(S390PCIBusDevice *pbdev, uint64_t iota);
 
 void s390_pci_get_clp_info(S390PCIBusDevice *pbdev);
 #else
@@ -68,6 +70,14 @@ static inline int s390_pci_get_aif(S390PCIBusDevice *pbdev, bool enable,
 {
     return -EINVAL;
 }
+static inline int s390_pci_probe_ioat(S390PCIBusDevice *pbdev)
+{
+    return -EINVAL;
+}
+static inline int s390_pci_set_ioat(S390PCIBusDevice *pbdev, uint64_t iota)
+{
+    return -EINVAL;
+}
 static inline void s390_pci_get_clp_info(S390PCIBusDevice *pbdev) { }
 #endif
 
-- 
2.27.0