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Subject[PATCH RFC v2 4/7] virtio-pci: define layout for virtio 1.0
From: Rusty Russell <rusty@rustcorp.com.au>

Based on patches by Michael S. Tsirkin <mst@redhat.com>, but I found it
hard to follow so changed to use structures which are more
self-documenting.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
include/uapi/linux/virtio_pci.h | 62 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)

diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 35b552c..28c2ce0 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -99,4 +99,66 @@
/* Vector value used to disable MSI for queue */
#define VIRTIO_MSI_NO_VECTOR 0xffff

+#ifndef VIRTIO_PCI_NO_MODERN
+
+/* IDs for different capabilities. Must all exist. */
+
+/* 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 cap_len; /* Generic PCI field: capability length */
+ __u8 type_and_bar; /* Upper 3 bits: bar.
+ * Lower 3 is VIRTIO_PCI_CAP_*_CFG. */
+ __le32 offset; /* Offset within bar. */
+ __le32 length; /* Length. */
+};
+
+#define VIRTIO_PCI_CAP_BAR_SHIFT 5
+#define VIRTIO_PCI_CAP_BAR_MASK 0x7
+#define VIRTIO_PCI_CAP_TYPE_SHIFT 0
+#define VIRTIO_PCI_CAP_TYPE_MASK 0x7
+
+struct virtio_pci_notify_cap {
+ struct virtio_pci_cap cap;
+ __le32 notify_off_multiplier; /* Multiplier for queue_notify_off. */
+};
+
+/* 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-write */
+ __le16 msix_config; /* read-write */
+ __le16 num_queues; /* read-only */
+ __u8 device_status; /* read-write */
+ __u8 config_generation; /* read-only */
+
+ /* About a specific virtqueue. */
+ __le16 queue_select; /* read-write */
+ __le16 queue_size; /* read-write, power of 2. */
+ __le16 queue_msix_vector; /* read-write */
+ __le16 queue_enable; /* read-write */
+ __le16 queue_notify_off; /* read-only */
+ __le32 queue_desc_lo; /* read-write */
+ __le32 queue_desc_hi; /* read-write */
+ __le32 queue_avail_lo; /* read-write */
+ __le32 queue_avail_hi; /* read-write */
+ __le32 queue_used_lo; /* read-write */
+ __le32 queue_used_hi; /* read-write */
+};
+
+#endif /* VIRTIO_PCI_NO_MODERN */
+
#endif
--
MST


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