[ipxe-devel] [PATCH 2/4] [virtio] Add virtio 1.0 constants and data structures

[Ladi Prosek]

Virtio 1.0 introduces new constants and data structures, common to
all devices as well as specific to virtio-net. This commit adds a
subset of these to be able to drive the virtio-net 1.0 network
device.

Signed-off-by: Ladi Prosek <lprosek at redhat.com>
---
 src/drivers/net/virtio-net.h   | 18 ++++++++++++++
 src/include/ipxe/virtio-pci.h  | 55 ++++++++++++++++++++++++++++++++++++++++++
 src/include/ipxe/virtio-ring.h |  8 ++++++
 3 files changed, 81 insertions(+)

diff --git a/src/drivers/net/virtio-net.h b/src/drivers/net/virtio-net.h
index 3abef28..2615d65 100644
--- a/src/drivers/net/virtio-net.h
+++ b/src/drivers/net/virtio-net.h
@@ -15,6 +15,14 @@
 #define VIRTIO_NET_F_HOST_ECN   13      /* Host can handle TSO[6] w/ ECN in. */
 #define VIRTIO_NET_F_HOST_UFO   14      /* Host can handle UFO in. */
 
+/* Virtio 1.0 feature bits for virtio net */
+#define VIRTIO_NET_F_MRG_RXBUF  15      /* Driver can merge receive buffers. */
+#define VIRTIO_NET_F_STATUS     16      /* Configuration status field is available. */
+#define VIRTIO_NET_F_CTRL_VQ    17      /* Control channel is available. */
+#define VIRTIO_NET_F_CTRL_RX    18      /* Control channel RX mode support. */
+#define VIRTIO_NET_F_CTRL_VLAN  19      /* Control channel VLAN filtering. */
+#define VIRTIO_NET_F_GUEST_ANNOUNCE 21  /* Driver can send gratuitous packets. */
+
 struct virtio_net_config
 {
    /* The config defining mac address (if VIRTIO_NET_F_MAC) */
@@ -41,4 +49,14 @@ struct virtio_net_hdr
    uint16_t csum_start;
    uint16_t csum_offset;
 };
+
+/* Virtio 1.0 version of the first element of the scatter-gather list. */
+struct virtio_net_hdr_modern
+{
+   struct virtio_net_hdr legacy;
+
+   /* Used only if VIRTIO_NET_F_MRG_RXBUF: */
+   uint16_t num_buffers;
+} __attribute__((packed));
+
 #endif /* _VIRTIO_NET_H_ */
diff --git a/src/include/ipxe/virtio-pci.h b/src/include/ipxe/virtio-pci.h
index a09c463..58c9bf2 100644
--- a/src/include/ipxe/virtio-pci.h
+++ b/src/include/ipxe/virtio-pci.h
@@ -37,6 +37,61 @@
 /* Virtio ABI version, this must match exactly */
 #define VIRTIO_PCI_ABI_VERSION          0
 
+/* PCI capability types: */
+#define VIRTIO_PCI_CAP_COMMON_CFG       1  /* Common configuration */
+#define VIRTIO_PCI_CAP_NOTIFY_CFG       2  /* Notifications */
+#define VIRTIO_PCI_CAP_ISR_CFG          3  /* ISR access */
+#define VIRTIO_PCI_CAP_DEVICE_CFG       4  /* Device specific configuration */
+#define VIRTIO_PCI_CAP_PCI_CFG          5  /* PCI configuration access */
+
+#define __u8       uint8_t
+#define __le16     uint16_t
+#define __le32     uint32_t
+#define __le64     uint64_t
+
+/* 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 cfg_type;    /* Identifies the structure. */
+    __u8 bar;         /* Where to find it. */
+    __u8 padding[3];  /* Pad to full dword. */
+    __le32 offset;    /* Offset within bar. */
+    __le32 length;    /* Length of the structure, in bytes. */
+} __attribute__((packed));
+
+struct virtio_pci_notify_cap {
+    struct virtio_pci_cap cap;
+    __le32 notify_off_multiplier; /* Multiplier for queue_notify_off. */
+} __attribute__((packed));
+
+/* 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 */
+} __attribute__((packed));
+
 static inline u32 vp_get_features(unsigned int ioaddr)
 {
    return inl(ioaddr + VIRTIO_PCI_HOST_FEATURES);
diff --git a/src/include/ipxe/virtio-ring.h b/src/include/ipxe/virtio-ring.h
index c687aca..e44d13c 100644
--- a/src/include/ipxe/virtio-ring.h
+++ b/src/include/ipxe/virtio-ring.h
@@ -8,9 +8,17 @@
 #define VIRTIO_CONFIG_S_DRIVER          2
 /* Driver has used its parts of the config, and is happy */
 #define VIRTIO_CONFIG_S_DRIVER_OK       4
+/* Driver has finished configuring features */
+#define VIRTIO_CONFIG_S_FEATURES_OK     8
 /* We've given up on this device. */
 #define VIRTIO_CONFIG_S_FAILED          0x80
 
+/* Virtio feature flags used to negotiate device and driver features. */
+/* Can the device handle any descriptor layout? */
+#define VIRTIO_F_ANY_LAYOUT             27
+/* v1.0 compliant. */
+#define VIRTIO_F_VERSION_1              32
+
 #define MAX_QUEUE_NUM      (256)
 
 #define VRING_DESC_F_NEXT  1
-- 
2.5.0