s390x/pci: enable adapter event notification for interpreted devices

Use the associated kvm ioctl operation to enable adapter event notification
and forwarding for devices when requested.  This feature will be set up
with or without firmware assist based upon the 'forwarding_assist' setting.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <20220902172737.170349-6-mjrosato@linux.ibm.com>
[thuth: Rename "forwarding_assist" property to "forwarding-assist"]
Signed-off-by: Thomas Huth <thuth@redhat.com>

hw/s390x/s390-pci-bus.c

@@ -190,7 +190,10 @@ void s390_pci_sclp_deconfigure(SCCB *sccb)
         rc = SCLP_RC_NO_ACTION_REQUIRED;
         break;
     default:
-        if (pbdev->summary_ind) {
+        if (pbdev->interp && (pbdev->fh & FH_MASK_ENABLE)) {
+            /* Interpreted devices were using interrupt forwarding */
+            s390_pci_kvm_aif_disable(pbdev);
+        } else if (pbdev->summary_ind) {
             pci_dereg_irqs(pbdev);
         }
         if (pbdev->iommu->enabled) {
@@ -1082,6 +1085,7 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
                 } else {
                     DPRINTF("zPCI interpretation facilities missing.\n");
                     pbdev->interp = false;
+                    pbdev->forwarding_assist = false;
                 }
             }
             pbdev->iommu->dma_limit = s390_pci_start_dma_count(s, pbdev);
@@ -1090,11 +1094,13 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
             if (!pbdev->interp) {
                 /* Do vfio passthrough but intercept for I/O */
                 pbdev->fh |= FH_SHM_VFIO;
+                pbdev->forwarding_assist = false;
             }
         } else {
             pbdev->fh |= FH_SHM_EMUL;
             /* Always intercept emulated devices */
             pbdev->interp = false;
+            pbdev->forwarding_assist = false;
         }
 
         if (s390_pci_msix_init(pbdev) && !pbdev->interp) {
@@ -1244,7 +1250,10 @@ static void s390_pcihost_reset(DeviceState *dev)
     /* Process all pending unplug requests */
     QTAILQ_FOREACH_SAFE(pbdev, &s->zpci_devs, link, next) {
         if (pbdev->unplug_requested) {
-            if (pbdev->summary_ind) {
+            if (pbdev->interp && (pbdev->fh & FH_MASK_ENABLE)) {
+                /* Interpreted devices were using interrupt forwarding */
+                s390_pci_kvm_aif_disable(pbdev);
+            } else if (pbdev->summary_ind) {
                 pci_dereg_irqs(pbdev);
             }
             if (pbdev->iommu->enabled) {
@@ -1382,7 +1391,10 @@ static void s390_pci_device_reset(DeviceState *dev)
         break;
     }
 
-    if (pbdev->summary_ind) {
+    if (pbdev->interp && (pbdev->fh & FH_MASK_ENABLE)) {
+        /* Interpreted devices were using interrupt forwarding */
+        s390_pci_kvm_aif_disable(pbdev);
+    } else if (pbdev->summary_ind) {
         pci_dereg_irqs(pbdev);
     }
     if (pbdev->iommu->enabled) {
@@ -1428,6 +1440,8 @@ static Property s390_pci_device_properties[] = {
     DEFINE_PROP_S390_PCI_FID("fid", S390PCIBusDevice, fid),
     DEFINE_PROP_STRING("target", S390PCIBusDevice, target),
     DEFINE_PROP_BOOL("interpret", S390PCIBusDevice, interp, true),
+    DEFINE_PROP_BOOL("forwarding-assist", S390PCIBusDevice, forwarding_assist,
+                     true),
     DEFINE_PROP_END_OF_LIST(),
 };
 

hw/s390x/s390-pci-inst.c

@@ -1066,6 +1066,32 @@ static void fmb_update(void *opaque)
     timer_mod(pbdev->fmb_timer, t + pbdev->pci_group->zpci_group.mui);
 }
 
+static int mpcifc_reg_int_interp(S390PCIBusDevice *pbdev, ZpciFib *fib)
+{
+    int rc;
+
+    rc = s390_pci_kvm_aif_enable(pbdev, fib, pbdev->forwarding_assist);
+    if (rc) {
+        DPRINTF("Failed to enable interrupt forwarding\n");
+        return rc;
+    }
+
+    return 0;
+}
+
+static int mpcifc_dereg_int_interp(S390PCIBusDevice *pbdev, ZpciFib *fib)
+{
+    int rc;
+
+    rc = s390_pci_kvm_aif_disable(pbdev);
+    if (rc) {
+        DPRINTF("Failed to disable interrupt forwarding\n");
+        return rc;
+    }
+
+    return 0;
+}
+
 int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
                         uintptr_t ra)
 {
@@ -1120,7 +1146,12 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
 
     switch (oc) {
     case ZPCI_MOD_FC_REG_INT:
-        if (pbdev->summary_ind) {
+        if (pbdev->interp) {
+            if (mpcifc_reg_int_interp(pbdev, &fib)) {
+                cc = ZPCI_PCI_LS_ERR;
+                s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
+            }
+        } else if (pbdev->summary_ind) {
             cc = ZPCI_PCI_LS_ERR;
             s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
         } else if (reg_irqs(env, pbdev, fib)) {
@@ -1129,7 +1160,12 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
         }
         break;
     case ZPCI_MOD_FC_DEREG_INT:
-        if (!pbdev->summary_ind) {
+        if (pbdev->interp) {
+            if (mpcifc_dereg_int_interp(pbdev, &fib)) {
+                cc = ZPCI_PCI_LS_ERR;
+                s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
+            }
+        } else if (!pbdev->summary_ind) {
             cc = ZPCI_PCI_LS_ERR;
             s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
         } else {

hw/s390x/s390-pci-kvm.c

@@ -11,12 +11,42 @@
 
 #include "qemu/osdep.h"
 
+#include <linux/kvm.h>
+
 #include "kvm/kvm_s390x.h"
 #include "hw/s390x/pv.h"
+#include "hw/s390x/s390-pci-bus.h"
 #include "hw/s390x/s390-pci-kvm.h"
+#include "hw/s390x/s390-pci-inst.h"
 #include "cpu_models.h"
 
 bool s390_pci_kvm_interp_allowed(void)
 {
     return kvm_s390_get_zpci_op() && !s390_is_pv();
 }
+
+int s390_pci_kvm_aif_enable(S390PCIBusDevice *pbdev, ZpciFib *fib, bool assist)
+{
+    struct kvm_s390_zpci_op args = {
+        .fh = pbdev->fh,
+        .op = KVM_S390_ZPCIOP_REG_AEN,
+        .u.reg_aen.ibv = fib->aibv,
+        .u.reg_aen.sb = fib->aisb,
+        .u.reg_aen.noi = FIB_DATA_NOI(fib->data),
+        .u.reg_aen.isc = FIB_DATA_ISC(fib->data),
+        .u.reg_aen.sbo = FIB_DATA_AISBO(fib->data),
+        .u.reg_aen.flags = (assist) ? 0 : KVM_S390_ZPCIOP_REGAEN_HOST
+    };
+
+    return kvm_vm_ioctl(kvm_state, KVM_S390_ZPCI_OP, &args);
+}
+
+int s390_pci_kvm_aif_disable(S390PCIBusDevice *pbdev)
+{
+    struct kvm_s390_zpci_op args = {
+        .fh = pbdev->fh,
+        .op = KVM_S390_ZPCIOP_DEREG_AEN
+    };
+
+    return kvm_vm_ioctl(kvm_state, KVM_S390_ZPCI_OP, &args);
+}

include/hw/s390x/s390-pci-bus.h

@@ -351,6 +351,7 @@ struct S390PCIBusDevice {
     bool pci_unplug_request_processed;
     bool unplug_requested;
     bool interp;
+    bool forwarding_assist;
     QTAILQ_ENTRY(S390PCIBusDevice) link;
 };
 

include/hw/s390x/s390-pci-kvm.h

@@ -12,13 +12,27 @@
 #ifndef HW_S390_PCI_KVM_H
 #define HW_S390_PCI_KVM_H
 
+#include "hw/s390x/s390-pci-bus.h"
+#include "hw/s390x/s390-pci-inst.h"
+
 #ifdef CONFIG_KVM
 bool s390_pci_kvm_interp_allowed(void);
+int s390_pci_kvm_aif_enable(S390PCIBusDevice *pbdev, ZpciFib *fib, bool assist);
+int s390_pci_kvm_aif_disable(S390PCIBusDevice *pbdev);
 #else
 static inline bool s390_pci_kvm_interp_allowed(void)
 {
     return false;
 }
+static inline int s390_pci_kvm_aif_enable(S390PCIBusDevice *pbdev, ZpciFib *fib,
+                                          bool assist)
+{
+    return -EINVAL;
+}
+static inline int s390_pci_kvm_aif_disable(S390PCIBusDevice *pbdev)
+{
+    return -EINVAL;
+}
 #endif
 
 #endif