KVM: remove in_range from io devices

This changes bus accesses to use high-level kvm_io_bus_read/kvm_io_bus_write
functions. in_range now becomes unused so it is removed from device ops in
favor of read/write callbacks performing range checks internally.

This allows aliasing (mostly for in-kernel virtio), as well as better error
handling by making it possible to pass errors up to userspace.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 26 insertions, 23 deletions

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 4082cdd468ed..8c3ac30ef9bd 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -358,8 +358,14 @@ static inline struct kvm_pit *speaker_to_pit(struct kvm_io_device *dev)
         return container_of(dev, struct kvm_pit, speaker_dev);
 }
 
-static void pit_ioport_write(struct kvm_io_device *this,
-                             gpa_t addr, int len, const void *data)
+static inline int pit_in_range(gpa_t addr)
+{
+        return ((addr >= KVM_PIT_BASE_ADDRESS) &&
+                (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH));
+}
+
+static int pit_ioport_write(struct kvm_io_device *this,
+                            gpa_t addr, int len, const void *data)
 {
         struct kvm_pit *pit = dev_to_pit(this);
         struct kvm_kpit_state *pit_state = &pit->pit_state;
@@ -367,6 +373,8 @@ static void pit_ioport_write(struct kvm_io_device *this,
         int channel, access;
         struct kvm_kpit_channel_state *s;
         u32 val = *(u32 *) data;
+        if (!pit_in_range(addr))
+                return -EOPNOTSUPP;
 
         val  &= 0xff;
         addr &= KVM_PIT_CHANNEL_MASK;
@@ -429,16 +437,19 @@ static void pit_ioport_write(struct kvm_io_device *this,
         }
 
         mutex_unlock(&pit_state->lock);
+        return 0;
 }
 
-static void pit_ioport_read(struct kvm_io_device *this,
-                            gpa_t addr, int len, void *data)
+static int pit_ioport_read(struct kvm_io_device *this,
+                           gpa_t addr, int len, void *data)
 {
         struct kvm_pit *pit = dev_to_pit(this);
         struct kvm_kpit_state *pit_state = &pit->pit_state;
         struct kvm *kvm = pit->kvm;
         int ret, count;
         struct kvm_kpit_channel_state *s;
+        if (!pit_in_range(addr))
+                return -EOPNOTSUPP;
 
         addr &= KVM_PIT_CHANNEL_MASK;
         s = &pit_state->channels[addr];
@@ -493,37 +504,36 @@ static void pit_ioport_read(struct kvm_io_device *this,
         memcpy(data, (char *)&ret, len);
 
         mutex_unlock(&pit_state->lock);
+        return 0;
 }
 
-static int pit_in_range(struct kvm_io_device *this, gpa_t addr,
-                        int len, int is_write)
-{
-        return ((addr >= KVM_PIT_BASE_ADDRESS) &&
-                (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH));
-}
-
-static void speaker_ioport_write(struct kvm_io_device *this,
-                                 gpa_t addr, int len, const void *data)
+static int speaker_ioport_write(struct kvm_io_device *this,
+                                gpa_t addr, int len, const void *data)
 {
         struct kvm_pit *pit = speaker_to_pit(this);
         struct kvm_kpit_state *pit_state = &pit->pit_state;
         struct kvm *kvm = pit->kvm;
         u32 val = *(u32 *) data;
+        if (addr != KVM_SPEAKER_BASE_ADDRESS)
+                return -EOPNOTSUPP;
 
         mutex_lock(&pit_state->lock);
         pit_state->speaker_data_on = (val >> 1) & 1;
         pit_set_gate(kvm, 2, val & 1);
         mutex_unlock(&pit_state->lock);
+        return 0;
 }
 
-static void speaker_ioport_read(struct kvm_io_device *this,
-                                gpa_t addr, int len, void *data)
+static int speaker_ioport_read(struct kvm_io_device *this,
+                               gpa_t addr, int len, void *data)
 {
         struct kvm_pit *pit = speaker_to_pit(this);
         struct kvm_kpit_state *pit_state = &pit->pit_state;
         struct kvm *kvm = pit->kvm;
         unsigned int refresh_clock;
         int ret;
+        if (addr != KVM_SPEAKER_BASE_ADDRESS)
+                return -EOPNOTSUPP;
 
         /* Refresh clock toggles at about 15us. We approximate as 2^14ns. */
         refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1;
@@ -535,12 +545,7 @@ static void speaker_ioport_read(struct kvm_io_device *this,
                 len = sizeof(ret);
         memcpy(data, (char *)&ret, len);
         mutex_unlock(&pit_state->lock);
-}
-
-static int speaker_in_range(struct kvm_io_device *this, gpa_t addr,
-                            int len, int is_write)
-{
-        return (addr == KVM_SPEAKER_BASE_ADDRESS);
+        return 0;
 }
 
 void kvm_pit_reset(struct kvm_pit *pit)
@@ -574,13 +579,11 @@ static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask)
 static const struct kvm_io_device_ops pit_dev_ops = {
         .read     = pit_ioport_read,
         .write    = pit_ioport_write,
-        .in_range = pit_in_range,
 };
 
 static const struct kvm_io_device_ops speaker_dev_ops = {
         .read     = speaker_ioport_read,
         .write    = speaker_ioport_write,
-        .in_range = speaker_in_range,
 };
 
 /* Caller must have writers lock on slots_lock */