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);
+        if (!adapter)
+                return -ENOMEM;
+
+        INIT_LIST_HEAD(&adapter->maps);
+        init_rwsem(&adapter->maps_lock);
+        atomic_set(&adapter->nr_maps, 0);
+        adapter->id = adapter_info.id;
+        adapter->isc = adapter_info.isc;
+        adapter->maskable = adapter_info.maskable;
+        adapter->masked = false;
+        adapter->swap = adapter_info.swap;
+        dev->kvm->arch.adapters[adapter->id] = adapter;
+
+        return 0;
+}
+
+int kvm_s390_mask_adapter(struct kvm *kvm, unsigned int id, bool masked)
+{
+        int ret;
+        struct s390_io_adapter *adapter = get_io_adapter(kvm, id);
+
+        if (!adapter || !adapter->maskable)
+                return -EINVAL;
+        ret = adapter->masked;
+        adapter->masked = masked;
+        return ret;
+}
+
+static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)
+{
+        struct s390_io_adapter *adapter = get_io_adapter(kvm, id);
+        struct s390_map_info *map;
+        int ret;
+
+        if (!adapter || !addr)
+                return -EINVAL;
+
+        map = kzalloc(sizeof(*map), GFP_KERNEL);
+        if (!map) {
+                ret = -ENOMEM;
+                goto out;
+        }
+        INIT_LIST_HEAD(&map->list);
+        map->guest_addr = addr;
+        map->addr = gmap_translate(addr, kvm->arch.gmap);
+        if (map->addr == -EFAULT) {
+                ret = -EFAULT;
+                goto out;
+        }
+        ret = get_user_pages_fast(map->addr, 1, 1, &map->page);
+        if (ret < 0)
+                goto out;
+        BUG_ON(ret != 1);
+        down_write(&adapter->maps_lock);
+        if (atomic_inc_return(&adapter->nr_maps) < MAX_S390_ADAPTER_MAPS) {
+                list_add_tail(&map->list, &adapter->maps);
+                ret = 0;
+        } else {
+                put_page(map->page);
+                ret = -EINVAL;
+        }
+        up_write(&adapter->maps_lock);
+out:
+        if (ret)
+                kfree(map);
+        return ret;
+}
+
+static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
+{
+        struct s390_io_adapter *adapter = get_io_adapter(kvm, id);
+        struct s390_map_info *map, *tmp;
+        int found = 0;
+
+        if (!adapter || !addr)
+                return -EINVAL;
+
+        down_write(&adapter->maps_lock);
+        list_for_each_entry_safe(map, tmp, &adapter->maps, list) {
+                if (map->guest_addr == addr) {
+                        found = 1;
+                        atomic_dec(&adapter->nr_maps);
+                        list_del(&map->list);
+                        put_page(map->page);
+                        kfree(map);
+                        break;
+                }
+        }
+        up_write(&adapter->maps_lock);
+
+        return found ? 0 : -EINVAL;
+}
+
+void kvm_s390_destroy_adapters(struct kvm *kvm)
+{
+        int i;
+        struct s390_map_info *map, *tmp;
+
+        for (i = 0; i < MAX_S390_IO_ADAPTERS; i++) {
+                if (!kvm->arch.adapters[i])
+                        continue;
+                list_for_each_entry_safe(map, tmp,
+                                         &kvm->arch.adapters[i]->maps, list) {
+                        list_del(&map->list);
+                        put_page(map->page);
+                        kfree(map);
+                }
+                kfree(kvm->arch.adapters[i]);
+        }
+}
+
+static int modify_io_adapter(struct kvm_device *dev,
+                             struct kvm_device_attr *attr)
+{
+        struct kvm_s390_io_adapter_req req;
+        struct s390_io_adapter *adapter;
+        int ret;
+
+        if (copy_from_user(&req, (void __user *)attr->addr, sizeof(req)))
+                return -EFAULT;
+
+        adapter = get_io_adapter(dev->kvm, req.id);
+        if (!adapter)
+                return -EINVAL;
+        switch (req.type) {
+        case KVM_S390_IO_ADAPTER_MASK:
+                ret = kvm_s390_mask_adapter(dev->kvm, req.id, req.mask);
+                if (ret > 0)
+                        ret = 0;
+                break;
+        case KVM_S390_IO_ADAPTER_MAP:
+                ret = kvm_s390_adapter_map(dev->kvm, req.id, req.addr);
+                break;
+        case KVM_S390_IO_ADAPTER_UNMAP:
+                ret = kvm_s390_adapter_unmap(dev->kvm, req.id, req.addr);
+                break;
+        default:
+                ret = -EINVAL;
+        }
+
+        return ret;
+}
+
 static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 {
         int r = 0;
@@ -1082,6 +1247,12 @@ static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
                 kvm_for_each_vcpu(i, vcpu, dev->kvm)
                         kvm_clear_async_pf_completion_queue(vcpu);
                 break;
+        case KVM_DEV_FLIC_ADAPTER_REGISTER:
+                r = register_io_adapter(dev, attr);
+                break;
+        case KVM_DEV_FLIC_ADAPTER_MODIFY:
+                r = modify_io_adapter(dev, attr);
+                break;
         default:
                 r = -EINVAL;
         }
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 9f1e99f12d4f..2e6fbb0b4f68 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -343,6 +343,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
         debug_unregister(kvm->arch.dbf);
         if (!kvm_is_ucontrol(kvm))
                 gmap_free(kvm->arch.gmap);
+        kvm_s390_destroy_adapters(kvm);
 }
 
 /* Section: vcpu related */
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index ed4750a5bc3c..5502cc951868 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -136,6 +136,7 @@ int __must_check kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
 int __must_check kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code);
 struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm,
                                                     u64 cr6, u64 schid);
+int kvm_s390_mask_adapter(struct kvm *kvm, unsigned int id, bool masked);
 
 /* implemented in priv.c */
 int kvm_s390_handle_b2(struct kvm_vcpu *vcpu);
@@ -162,5 +163,6 @@ int kvm_s390_handle_diag(struct kvm_vcpu *vcpu);
 /* implemented in interrupt.c */
 int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
 int psw_extint_disabled(struct kvm_vcpu *vcpu);
+void kvm_s390_destroy_adapters(struct kvm *kvm);
 
 #endif