virtio: add modern config accessors

virtio 1.0 defines config space as LE,
as opposed to pre-1.0 which was native endian.

Add API for transports to execute word/dword accesses in
little endian format - will be useful for mmio
and pci (byte access is also wrapped, for completeness).

For simplicity, we still keep config in host native
endian format, byteswap to LE on guest access.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index cae5ecab19cb0f7c47442f626c7f6fa9844f83f1..fb49ffcb2d47345b3a21e6bb0126b921d7411b1a 100644 (file)
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -729,6 +729,102 @@ void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data)
     }
 }
 
+uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint8_t val;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return (uint32_t)-1;
+    }
+
+    k->get_config(vdev, vdev->config);
+
+    val = ldub_p(vdev->config + addr);
+    return val;
+}
+
+uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint16_t val;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return (uint32_t)-1;
+    }
+
+    k->get_config(vdev, vdev->config);
+
+    val = lduw_le_p(vdev->config + addr);
+    return val;
+}
+
+uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint32_t val;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return (uint32_t)-1;
+    }
+
+    k->get_config(vdev, vdev->config);
+
+    val = ldl_le_p(vdev->config + addr);
+    return val;
+}
+
+void virtio_config_modern_writeb(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint8_t val = data;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return;
+    }
+
+    stb_p(vdev->config + addr, val);
+
+    if (k->set_config) {
+        k->set_config(vdev, vdev->config);
+    }
+}
+
+void virtio_config_modern_writew(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint16_t val = data;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return;
+    }
+
+    stw_le_p(vdev->config + addr, val);
+
+    if (k->set_config) {
+        k->set_config(vdev, vdev->config);
+    }
+}
+
+void virtio_config_modern_writel(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data)
+{
+    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
+    uint32_t val = data;
+
+    if (addr + sizeof(val) > vdev->config_len) {
+        return;
+    }
+
+    stl_le_p(vdev->config + addr, val);
+
+    if (k->set_config) {
+        k->set_config(vdev, vdev->config);
+    }
+}
+
 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr)
 {
     vdev->vq[n].vring.desc = addr;

diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index b9e36f95d381f76c34e83724df24cdc579068503..473fb75e2881cce4917a98264e41924c7ffbe4a1 100644 (file)
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -174,6 +174,15 @@ uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
+uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
+uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
+uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
+void virtio_config_modern_writeb(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data);
+void virtio_config_modern_writew(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data);
+void virtio_config_modern_writel(VirtIODevice *vdev,
+                                 uint32_t addr, uint32_t data);
 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);