KVM: s390: adapter interrupt sources

Add a new interface to register/deregister sources of adapter interrupts
identified by an unique id via the flic. Adapters may also be maskable
and carry a list of pinned pages.

These adapters will be used by irq routing later.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

6 files changed, 265 insertions, 1 deletions

diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt
index 410fa673e5b6..4ceef53164b0 100644
--- a/Documentation/virtual/kvm/devices/s390_flic.txt
+++ b/Documentation/virtual/kvm/devices/s390_flic.txt
@@ -12,6 +12,7 @@ FLIC provides support to
 - inspect currently pending interrupts (KVM_FLIC_GET_ALL_IRQS)
 - purge all pending floating interrupts (KVM_DEV_FLIC_CLEAR_IRQS)
 - enable/disable for the guest transparent async page faults
+- register and modify adapter interrupt sources (KVM_DEV_FLIC_ADAPTER_*)
 
 Groups:
   KVM_DEV_FLIC_ENQUEUE
@@ -44,3 +45,47 @@ Groups:
     Disables async page faults for the guest and waits until already pending
     async page faults are done. This is necessary to trigger a completion interrupt
     for every init interrupt before migrating the interrupt list.
+
+  KVM_DEV_FLIC_ADAPTER_REGISTER
+    Register an I/O adapter interrupt source. Takes a kvm_s390_io_adapter
+    describing the adapter to register:
+
+struct kvm_s390_io_adapter {
+        __u32 id;
+        __u8 isc;
+        __u8 maskable;
+        __u8 swap;
+        __u8 pad;
+};
+
+   id contains the unique id for the adapter, isc the I/O interruption subclass
+   to use, maskable whether this adapter may be masked (interrupts turned off)
+   and swap whether the indicators need to be byte swapped.
+
+
+  KVM_DEV_FLIC_ADAPTER_MODIFY
+    Modifies attributes of an existing I/O adapter interrupt source. Takes
+    a kvm_s390_io_adapter_req specifiying the adapter and the operation:
+
+struct kvm_s390_io_adapter_req {
+        __u32 id;
+        __u8 type;
+        __u8 mask;
+        __u16 pad0;
+        __u64 addr;
+};
+
+    id specifies the adapter and type the operation. The supported operations
+    are:
+
+    KVM_S390_IO_ADAPTER_MASK
+      mask or unmask the adapter, as specified in mask
+
+    KVM_S390_IO_ADAPTER_MAP
+      perform a gmap translation for the guest address provided in addr,
+      pin a userspace page for the translated address and add it to the
+      list of mappings
+
+    KVM_S390_IO_ADAPTER_UNMAP
+      release a userspace page for the translated address specified in addr
+      from the list of mappings
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 734d302ba389..0d5235262707 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -19,6 +19,7 @@
 #include <linux/kvm.h>
 #include <asm/debug.h>
 #include <asm/cpu.h>
+#include <asm/isc.h>
 
 #define KVM_MAX_VCPUS 64
 #define KVM_USER_MEM_SLOTS 32
@@ -245,6 +246,27 @@ struct kvm_vm_stat {
 struct kvm_arch_memory_slot {
 };
 
+struct s390_map_info {
+        struct list_head list;
+        __u64 guest_addr;
+        __u64 addr;
+        struct page *page;
+};
+
+struct s390_io_adapter {
+        unsigned int id;
+        int isc;
+        bool maskable;
+        bool masked;
+        bool swap;
+        struct rw_semaphore maps_lock;
+        struct list_head maps;
+        atomic_t nr_maps;
+};
+
+#define MAX_S390_IO_ADAPTERS ((MAX_ISC + 1) * 8)
+#define MAX_S390_ADAPTER_MAPS 256
+
 struct kvm_arch{
         struct sca_block *sca;
         debug_info_t *dbf;
@@ -252,6 +274,7 @@ struct kvm_arch{
         struct kvm_device *flic;
         struct gmap *gmap;
         int css_support;
+        struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS];
 };
 
 #define KVM_HVA_ERR_BAD         (-1UL)
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index 2f0ade24f96a..c003c6a73b1e 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -22,6 +22,8 @@
 #define KVM_DEV_FLIC_CLEAR_IRQS         3
 #define KVM_DEV_FLIC_APF_ENABLE         4
 #define KVM_DEV_FLIC_APF_DISABLE_WAIT   5
+#define KVM_DEV_FLIC_ADAPTER_REGISTER   6
+#define KVM_DEV_FLIC_ADAPTER_MODIFY     7
 /*
  * We can have up to 4*64k pending subchannels + 8 adapter interrupts,
  * as well as up  to ASYNC_PF_PER_VCPU*KVM_MAX_VCPUS pfault done interrupts.
@@ -32,6 +34,26 @@
 #define KVM_S390_MAX_FLOAT_IRQS 266250
 #define KVM_S390_FLIC_MAX_BUFFER        0x2000000
 
+struct kvm_s390_io_adapter {
+        __u32 id;
+        __u8 isc;
+        __u8 maskable;
+        __u8 swap;
+        __u8 pad;
+};
+
+#define KVM_S390_IO_ADAPTER_MASK 1
+#define KVM_S390_IO_ADAPTER_MAP 2
+#define KVM_S390_IO_ADAPTER_UNMAP 3
+
+struct kvm_s390_io_adapter_req {
+        __u32 id;
+        __u8 type;
+        __u8 mask;
+        __u16 pad0;
+        __u64 addr;
+};
+
 /* for KVM_GET_REGS and KVM_SET_REGS */
 struct kvm_regs {
         /* general purpose regs for s390 */
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 79d2e4fa9f9c..7ecef5a18e25 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -1,7 +1,7 @@
 /*
  * handling kvm guest interrupts
  *
- * Copyright IBM Corp. 2008
+ * Copyright IBM Corp. 2008,2014
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License (version 2 only)
@@ -1054,6 +1054,171 @@ static int enqueue_floating_irq(struct kvm_device *dev,
         return r;
 }
 
+static struct s390_io_adapter *get_io_adapter(struct kvm *kvm, unsigned int id)
+{
+        if (id >= MAX_S390_IO_ADAPTERS)
+                return NULL;
+        return kvm->arch.adapters[id];
+}
+
+static int register_io_adapter(struct kvm_device *dev,
+                               struct kvm_device_attr *attr)
+{
+        struct s390_io_adapter *adapter;
+        struct kvm_s390_io_adapter adapter_info;
+
+        if (copy_from_user(&adapter_info,
+                           (void __user *)attr->addr, sizeof(adapter_info)))
+                return -EFAULT;
+
+        if ((adapter_info.id >= MAX_S390_IO_ADAPTERS) ||
+            (dev->kvm->arch.adapters[adapter_info.id] != NULL))
+                return -EINVAL;
+
+        adapter = kzalloc(sizeof(*adapter), GFP_KERNEL);