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, 12 insertions, 8 deletions

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 1851aec8a7da..1d1bb75dc7bc 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -430,8 +430,7 @@ static u32 elcr_ioport_read(void *opaque, u32 addr1)
         return s->elcr;
 }
 
-static int picdev_in_range(struct kvm_io_device *this, gpa_t addr,
-                           int len, int is_write)
+static int picdev_in_range(gpa_t addr)
 {
         switch (addr) {
         case 0x20:
@@ -451,16 +450,18 @@ static inline struct kvm_pic *to_pic(struct kvm_io_device *dev)
         return container_of(dev, struct kvm_pic, dev);
 }
 
-static void picdev_write(struct kvm_io_device *this,
+static int picdev_write(struct kvm_io_device *this,
                          gpa_t addr, int len, const void *val)
 {
         struct kvm_pic *s = to_pic(this);
         unsigned char data = *(unsigned char *)val;
+        if (!picdev_in_range(addr))
+                return -EOPNOTSUPP;
 
         if (len != 1) {
                 if (printk_ratelimit())
                         printk(KERN_ERR "PIC: non byte write\n");
-                return;
+                return 0;
         }
         pic_lock(s);
         switch (addr) {
@@ -476,18 +477,21 @@ static void picdev_write(struct kvm_io_device *this,
                 break;
         }
         pic_unlock(s);
+        return 0;
 }
 
-static void picdev_read(struct kvm_io_device *this,
-                        gpa_t addr, int len, void *val)
+static int picdev_read(struct kvm_io_device *this,
+                       gpa_t addr, int len, void *val)
 {
         struct kvm_pic *s = to_pic(this);
         unsigned char data = 0;
+        if (!picdev_in_range(addr))
+                return -EOPNOTSUPP;
 
         if (len != 1) {
                 if (printk_ratelimit())
                         printk(KERN_ERR "PIC: non byte read\n");
-                return;
+                return 0;
         }
         pic_lock(s);
         switch (addr) {
@@ -504,6 +508,7 @@ static void picdev_read(struct kvm_io_device *this,
         }
         *(unsigned char *)val = data;
         pic_unlock(s);
+        return 0;
 }
 
 /*
@@ -526,7 +531,6 @@ static void pic_irq_request(void *opaque, int level)
 static const struct kvm_io_device_ops picdev_ops = {
         .read     = picdev_read,
         .write    = picdev_write,
-        .in_range = picdev_in_range,
 };
 
 struct kvm_pic *kvm_create_pic(struct kvm *kvm)