The KVM_S390_ZPCI_OP ioctl provides a series of operations that
can be invoked to manage hardware-assisted virtualization features
for s390x PCI passthrough.

Signed-off-by: Matthew Rosato <mjros...@linux.ibm.com>
---
 Documentation/virt/kvm/api.rst | 60 ++++++++++++++++++++++++++
 arch/s390/kvm/kvm-s390.c       | 26 ++++++++++++
 arch/s390/kvm/pci.c            | 77 ++++++++++++++++++++++++++++++++++
 arch/s390/kvm/pci.h            |  3 +-
 include/uapi/linux/kvm.h       | 43 +++++++++++++++++++
 5 files changed, 208 insertions(+), 1 deletion(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 9f3172376ec3..c642ff891cf2 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -5574,6 +5574,66 @@ enabled with ``arch_prctl()``, but this may change in 
the future.
 The offsets of the state save areas in struct kvm_xsave follow the contents
 of CPUID leaf 0xD on the host.
 
+4.134 KVM_S390_ZPCI_OP
+--------------------
+
+:Capability: KVM_CAP_S390_ZPCI_OP
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: struct kvm_s390_zpci_op (in, out)
+:Returns: 0 on success, <0 on error
+
+Used to manage hardware-assisted virtualization features for zPCI devices.
+
+Parameters are specified via the following structure::
+
+  struct kvm_s390_zpci_op {
+       /* in */
+       __u32 fh;               /* target device */
+       __u8  op;               /* operation to perform */
+       __u8  pad[3];
+       union {
+               /* for KVM_S390_ZPCIOP_REG_INT */
+               struct {
+                       __u64 ibv;      /* Guest addr of interrupt bit vector */
+                       __u64 sb;       /* Guest addr of summary bit */
+                       __u32 flags;
+                       __u32 noi;      /* Number of interrupts */
+                       __u8 isc;       /* Guest interrupt subclass */
+                       __u8 sbo;       /* Offset of guest summary bit vector */
+                       __u16 pad;
+               } reg_int;
+               /* for KVM_S390_ZPCIOP_REG_IOAT */
+               struct {
+                       __u64 iota;     /* I/O Translation settings */
+               } reg_ioat;
+               __u8 reserved[64];
+       } u;
+       /* out */
+       __u32 newfh;            /* updated device handle */
+  };
+
+The type of operation is specified in the "op" field.
+KVM_S390_ZPCIOP_INIT is used to assocaite a zPCI function with this vm.
+Conversely, KVM_S390_ZPCIOP_END is used to terminate that association.
+KVM_S390_ZPCIOP_START_INTERP is used to enable interpretive execution
+for the specified zPCI function for this VM; KVM_S390_ZPCIOP_STOP_INTERP
+is used to subsequently disable interpretive execution.
+KVM_S390_ZPCIOP_REG_INT is used to register the VM for adapter interruption
+forwarding, which will allow firmware delivery of interrupts directly to
+the vm, with KVM providing a backup delivery mechanism;
+KVM_S390_ZPCIOP_DEREG_INT is used to subsequently disable interrupt forwarding.
+KVM_S390_ZPCIOP_REG_IOAT is used to enable KVM-managed IOMMU ops to begin
+synchronizing guest and host DMA tables; KVM_S390_ZPCIOP_DEREG_IOAT is used
+to subsequently disable IOMMU mapping.
+
+The target zPCI function must also be specified via the "fh" field.  For the
+KVM_S390_ZPCIOP_REG_INT operation, additional information to establish the
+interrupt forwarding must be provided via the "reg_int" struct.  For the
+KVM_S390_ZPCIOP_REG_IOAT operation, guest table format and location must be
+specified via the "reg_ioat" struct.
+
+The "reserved" field is meant for future extensions.
 
 5. The kvm_run structure
 ========================
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 84acaf59a7d3..613101ba29be 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -616,6 +616,15 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
        case KVM_CAP_S390_PROTECTED:
                r = is_prot_virt_host();
                break;
+       case KVM_CAP_S390_ZPCI_OP:
+               if (IS_ENABLED(CONFIG_S390_KVM_IOMMU) && test_facility(69) &&
+                   test_facility(70) && test_facility(71) &&
+                   test_facility(72)) {
+                       r = 1;
+               } else {
+                       r = 0;
+               }
+               break;
        default:
                r = 0;
        }
@@ -2532,6 +2541,23 @@ long kvm_arch_vm_ioctl(struct file *filp,
                }
                break;
        }
+       case KVM_S390_ZPCI_OP: {
+               struct kvm_s390_zpci_op args;
+
+               r = -EINVAL;
+               if (!IS_ENABLED(CONFIG_VFIO_PCI))
+                       break;
+               if (copy_from_user(&args, argp, sizeof(args))) {
+                       r = -EFAULT;
+                       break;
+               }
+               r = kvm_s390_pci_zpci_op(kvm, &args);
+               if (r)
+                       break;
+               if (copy_to_user(argp, &args, sizeof(args)))
+                       r = -EFAULT;
+               break;
+       }
        default:
                r = -ENOTTY;
        }
diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
index 40d2fadbfbd5..15b581915cd7 100644
--- a/arch/s390/kvm/pci.c
+++ b/arch/s390/kvm/pci.c
@@ -739,6 +739,83 @@ void kvm_s390_pci_clear_list(struct kvm *kvm)
        }
 }
 
+static int kvm_s390_pci_zpci_reg_int(struct zpci_dev *zdev,
+                                    struct kvm_s390_zpci_op *args)
+{
+       struct zpci_fib fib = {};
+
+       fib.fmt0.aibv = args->u.reg_int.ibv;
+       fib.fmt0.isc = args->u.reg_int.isc;
+       fib.fmt0.noi = args->u.reg_int.noi;
+       if (args->u.reg_int.sb != 0) {
+               fib.fmt0.aisb = args->u.reg_int.sb;
+               fib.fmt0.aisbo = args->u.reg_int.sbo;
+               fib.fmt0.sum = 1;
+       } else {
+               fib.fmt0.aisb = 0;
+               fib.fmt0.aisbo = 0;
+               fib.fmt0.sum = 0;
+       }
+
+       if (args->u.reg_int.flags & KVM_S390_ZPCIOP_REGINT_HOST)
+               return kvm_s390_pci_aif_enable(zdev, &fib, true);
+       else
+               return kvm_s390_pci_aif_enable(zdev, &fib, false);
+}
+
+int kvm_s390_pci_zpci_op(struct kvm *kvm, struct kvm_s390_zpci_op *args)
+{
+       struct kvm_zdev *kzdev;
+       struct zpci_dev *zdev;
+       int r;
+
+       if (args->op == KVM_S390_ZPCIOP_INIT) {
+               zdev = get_zdev_by_fh(args->fh);
+               if (!zdev)
+                       return -ENODEV;
+       } else {
+               kzdev = get_kzdev_by_fh(kvm, args->fh);
+               if (!kzdev || !kzdev->zdev)
+                       return -ENODEV;
+               zdev = kzdev->zdev;
+       }
+
+       switch (args->op) {
+       case KVM_S390_ZPCIOP_INIT:
+               r = kvm_s390_pci_zpci_start(kvm, zdev);
+               break;
+       case KVM_S390_ZPCIOP_END:
+               r = kvm_s390_pci_zpci_stop(kvm, zdev);
+               break;
+       case KVM_S390_ZPCIOP_START_INTERP:
+               r = kvm_s390_pci_interp_enable(zdev);
+               break;
+       case KVM_S390_ZPCIOP_STOP_INTERP:
+               r = kvm_s390_pci_interp_disable(zdev, false);
+               break;
+       case KVM_S390_ZPCIOP_REG_INT:
+               r = kvm_s390_pci_zpci_reg_int(zdev, args);
+               break;
+       case KVM_S390_ZPCIOP_DEREG_INT:
+               r = kvm_s390_pci_aif_disable(zdev, false);
+               break;
+       case KVM_S390_ZPCIOP_REG_IOAT:
+               r = kvm_s390_pci_ioat_enable(zdev, args->u.reg_ioat.iota);
+               break;
+       case KVM_S390_ZPCIOP_DEREG_IOAT:
+               r = kvm_s390_pci_ioat_disable(zdev);
+               break;
+       default:
+               r = -EINVAL;
+       }
+
+       /* On success, always return the current host function handle */
+       if (r == 0)
+               args->newfh = zdev->fh;
+
+       return r;
+}
+
 int kvm_s390_pci_init(void)
 {
        int rc;
diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/pci.h
index 2cb1b27396c1..c30b0bacca00 100644
--- a/arch/s390/kvm/pci.h
+++ b/arch/s390/kvm/pci.h
@@ -12,6 +12,7 @@
 
 #include <linux/pci.h>
 #include <linux/mutex.h>
+#include <linux/kvm.h>
 #include <linux/kvm_host.h>
 #include <asm/airq.h>
 #include <asm/kvm_pci.h>
@@ -56,7 +57,7 @@ int kvm_s390_pci_zpci_start(struct kvm *kvm, struct zpci_dev 
*zdev);
 int kvm_s390_pci_zpci_stop(struct kvm *kvm, struct zpci_dev *zdev);
 void kvm_s390_pci_init_list(struct kvm *kvm);
 void kvm_s390_pci_clear_list(struct kvm *kvm);
-
+int kvm_s390_pci_zpci_op(struct kvm *kvm, struct kvm_s390_zpci_op *args);
 int kvm_s390_pci_init(void);
 
 #endif /* __KVM_S390_PCI_H */
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 507ee1f2aa96..be8693ccc833 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1135,6 +1135,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_XSAVE2 208
 #define KVM_CAP_SYS_ATTRIBUTES 209
 #define KVM_CAP_PPC_AIL_MODE_3 210
+#define KVM_CAP_S390_ZPCI_OP 211
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -2049,4 +2050,46 @@ struct kvm_stats_desc {
 /* Available with KVM_CAP_XSAVE2 */
 #define KVM_GET_XSAVE2           _IOR(KVMIO,  0xcf, struct kvm_xsave)
 
+/* Available with KVM_CAP_S390_ZPCI_OP */
+#define KVM_S390_ZPCI_OP         _IOW(KVMIO,  0xd0, struct kvm_s390_zpci_op)
+
+struct kvm_s390_zpci_op {
+       /* in */
+       __u32 fh;               /* target device */
+       __u8  op;               /* operation to perform */
+       __u8  pad[3];
+       union {
+               /* for KVM_S390_ZPCIOP_REG_INT */
+               struct {
+                       __u64 ibv;      /* Guest addr of interrupt bit vector */
+                       __u64 sb;       /* Guest addr of summary bit */
+                       __u32 flags;
+                       __u32 noi;      /* Number of interrupts */
+                       __u8 isc;       /* Guest interrupt subclass */
+                       __u8 sbo;       /* Offset of guest summary bit vector */
+                       __u16 pad;
+               } reg_int;
+               /* for KVM_S390_ZPCIOP_REG_IOAT */
+               struct {
+                       __u64 iota;     /* I/O Translation settings */
+               } reg_ioat;
+               __u8 reserved[64];
+       } u;
+       /* out */
+       __u32 newfh;            /* updated device handle */
+};
+
+/* types for kvm_s390_zpci_op->op */
+#define KVM_S390_ZPCIOP_INIT           0
+#define KVM_S390_ZPCIOP_END            1
+#define KVM_S390_ZPCIOP_START_INTERP   2
+#define KVM_S390_ZPCIOP_STOP_INTERP    3
+#define KVM_S390_ZPCIOP_REG_INT                4
+#define KVM_S390_ZPCIOP_DEREG_INT      5
+#define KVM_S390_ZPCIOP_REG_IOAT       6
+#define KVM_S390_ZPCIOP_DEREG_IOAT     7
+
+/* flags for kvm_s390_zpci_op->u.reg_int.flags */
+#define KVM_S390_ZPCIOP_REGINT_HOST    (1 << 0)
+
 #endif /* __LINUX_KVM_H */
-- 
2.27.0

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Reply via email to