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, 16 insertions, 10 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 0edc366ecf89..594606526620 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2512,19 +2512,25 @@ void kvm_io_bus_destroy(struct kvm_io_bus *bus)
         }
 }
 
-struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
-                                          gpa_t addr, int len, int is_write)
+/* kvm_io_bus_write - called under kvm->slots_lock */
+int kvm_io_bus_write(struct kvm_io_bus *bus, gpa_t addr,
+                     int len, const void *val)
 {
         int i;
+        for (i = 0; i < bus->dev_count; i++)
+                if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
+                        return 0;
+        return -EOPNOTSUPP;
+}
 
-        for (i = 0; i < bus->dev_count; i++) {
-                struct kvm_io_device *pos = bus->devs[i];
-
-                if (kvm_iodevice_in_range(pos, addr, len, is_write))
-                        return pos;
-        }
-
-        return NULL;
+/* kvm_io_bus_read - called under kvm->slots_lock */
+int kvm_io_bus_read(struct kvm_io_bus *bus, gpa_t addr, int len, void *val)
+{
+        int i;
+        for (i = 0; i < bus->dev_count; i++)
+                if (!kvm_iodevice_read(bus->devs[i], addr, len, val))
+                        return 0;
+        return -EOPNOTSUPP;
 }
 
 void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus,