virtio: add read/write functions and macros

Add macros to read/write virtio registers.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 86 insertions, 0 deletions

diff --git a/src/hw/virtio-pci.h b/src/hw/virtio-pci.h
index 147e529e..f7510f2e 100644
--- a/src/hw/virtio-pci.h
+++ b/src/hw/virtio-pci.h
@@ -127,6 +127,92 @@ struct vp_device {
     struct vp_cap common, notify, isr, device, legacy;
 };
 
+static inline u64 _vp_read(struct vp_cap *cap, u32 offset, u8 size)
+{
+    u32 addr = cap->addr + offset;
+    u64 var;
+
+    if (cap->is_io) {
+        switch (size) {
+        case 8:
+            var = inl(addr);
+            var |= (u64)inl(addr+4) << 32;
+            break;
+        case 4:
+            var = inl(addr);
+            break;
+        case 2:
+            var = inw(addr);
+            break;
+        case 1:
+            var = inb(addr);
+            break;
+        default:
+            var = 0;
+        }
+    } else {
+        switch (size) {
+        case 8:
+            var = readl((void*)addr);
+            var |= (u64)readl((void*)(addr+4)) << 32;
+            break;
+        case 4:
+            var = readl((void*)addr);
+            break;
+        case 2:
+            var = readw((void*)addr);
+            break;
+        case 1:
+            var = readb((void*)addr);
+            break;
+        default:
+            var = 0;
+        }
+    }
+    dprintf(9, "vp read   %x (%d) -> 0x%llx\n", addr, size, var);
+    return var;
+}
+
+static inline void _vp_write(struct vp_cap *cap, u32 offset, u8 size, u64 var)
+{
+    u32 addr = cap->addr + offset;
+
+    dprintf(9, "vp write  %x (%d) <- 0x%llx\n", addr, size, var);
+    if (cap->is_io) {
+        switch (size) {
+        case 4:
+            outl(var, addr);
+            break;
+        case 2:
+            outw(var, addr);
+            break;
+        case 1:
+            outb(var, addr);
+            break;
+        }
+    } else {
+        switch (size) {
+        case 4:
+            writel((void*)addr, var);
+            break;
+        case 2:
+            writew((void*)addr, var);
+            break;
+        case 1:
+            writeb((void*)addr, var);
+            break;
+        }
+    }
+}
+
+#define vp_read(_cap, _struct, _field)        \
+    _vp_read(_cap, offsetof(_struct, _field), \
+             sizeof(((_struct *)0)->_field))
+
+#define vp_write(_cap, _struct, _field, _var)           \
+    _vp_write(_cap, offsetof(_struct, _field),          \
+             sizeof(((_struct *)0)->_field), _var)
+
 static inline u32 vp_get_features(struct vp_device *vp)
 {
     return inl(GET_LOWFLAT(vp->ioaddr) + VIRTIO_PCI_HOST_FEATURES);