Based on patch by Michael S. Tsirkin <mst@xxxxxxxxxx>, but I found it
hard to follow so changed to use structures which are more
self-documenting.
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
include/linux/virtio_pci.h | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h
--- a/include/linux/virtio_pci.h
+++ b/include/linux/virtio_pci.h
@@ -92,4 +92,45 @@
/* The alignment to use between consumer and producer parts of vring.
* x86 pagesize again. */
#define VIRTIO_PCI_VRING_ALIGN 4096
+
+/* IDs for different capabilities. Must all exist. */
+/* FIXME: Do we win from separating ISR, NOTIFY and COMMON? */
+/* Common configuration */
+#define VIRTIO_PCI_CAP_COMMON_CFG 1
+/* Notifications */
+#define VIRTIO_PCI_CAP_NOTIFY_CFG 2
+/* ISR access */
+#define VIRTIO_PCI_CAP_ISR_CFG 3
+/* Device specific confiuration */
+#define VIRTIO_PCI_CAP_DEVICE_CFG 4
+
+/* This is the PCI capability header: */
+struct virtio_pci_cap {
+ u8 cap_vndr; /* Generic PCI field: PCI_CAP_ID_VNDR */
+ u8 cap_next; /* Generic PCI field: next ptr. */
+ u8 cfg_type; /* One of the VIRTIO_PCI_CAP_*_CFG. */
+/* FIXME: Should we use a bir, instead of raw bar number? */
+ u8 bar; /* Where to find it. */
+ __le32 offset; /* Offset within bar. */
+ __le32 length; /* Length. */
+};
+
+/* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
+struct virtio_pci_common_cfg {
+ /* About the whole device. */
+ __le32 device_feature_select; /* read-write */
+ __le32 device_feature; /* read-only */
+ __le32 guest_feature_select; /* read-write */
+ __le32 guest_feature; /* read-only */
+ __le16 msix_config; /* read-write */
+ __u8 device_status; /* read-write */
+ __u8 unused;
+
+ /* About a specific virtqueue. */
+ __le16 queue_select; /* read-write */
+ __le16 queue_align; /* read-write, power of 2. */
+ __le16 queue_size; /* read-write, power of 2. */
+ __le16 queue_msix_vector;/* read-write */
+ __le64 queue_address; /* read-write: 0xFFFFFFFFFFFFFFFF == DNE. */
+};
#endif
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