[virtio] Add virtio 1.0 PCI support

This commit adds support for driving virtio 1.0 PCI devices.  In
addition to various helpers, a number of vpm_ functions are introduced
to be used instead of their legacy vp_ counterparts when accessing
virtio 1.0 (aka modern) devices.

Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 147 insertions, 0 deletions

diff --git a/src/include/ipxe/virtio-pci.h b/src/include/ipxe/virtio-pci.h
index 8076f20c8..c7452c82f 100644
--- a/src/include/ipxe/virtio-pci.h
+++ b/src/include/ipxe/virtio-pci.h
@@ -97,6 +97,44 @@ struct virtio_pci_common_cfg {
     __le32 queue_used_hi;         /* read-write */
 };
 
+/* Virtio 1.0 PCI region descriptor. We support memory mapped I/O, port I/O,
+ * and PCI config space access via the cfg PCI capability as a fallback. */
+struct virtio_pci_region {
+    void *base;
+    size_t length;
+    u8 bar;
+
+/* How to interpret the base field */
+#define VIRTIO_PCI_REGION_TYPE_MASK  0x00000003
+/* The base field is a memory address */
+#define VIRTIO_PCI_REGION_MEMORY     0x00000000
+/* The base field is a port address */
+#define VIRTIO_PCI_REGION_PORT       0x00000001
+/* The base field is an offset within the PCI bar */
+#define VIRTIO_PCI_REGION_PCI_CONFIG 0x00000002
+    unsigned flags;
+};
+
+/* Virtio 1.0 device state */
+struct virtio_pci_modern_device {
+    struct pci_device *pci;
+
+    /* VIRTIO_PCI_CAP_PCI_CFG position */
+    int cfg_cap_pos;
+
+    /* VIRTIO_PCI_CAP_COMMON_CFG data */
+    struct virtio_pci_region common;
+
+    /* VIRTIO_PCI_CAP_DEVICE_CFG data */
+    struct virtio_pci_region device;
+
+    /* VIRTIO_PCI_CAP_ISR_CFG data */
+    struct virtio_pci_region isr;
+
+    /* VIRTIO_PCI_CAP_NOTIFY_CFG data */
+    int notify_cap_pos;
+};
+
 static inline u32 vp_get_features(unsigned int ioaddr)
 {
    return inl(ioaddr + VIRTIO_PCI_HOST_FEATURES);
@@ -156,6 +194,115 @@ static inline void vp_del_vq(unsigned int ioaddr, int queue_index)
    outl(0, ioaddr + VIRTIO_PCI_QUEUE_PFN);
 }
 
+struct vring_virtqueue;
+
 int vp_find_vq(unsigned int ioaddr, int queue_index,
                struct vring_virtqueue *vq);
+
+/* Virtio 1.0 I/O routines abstract away the three possible HW access
+ * mechanisms - memory, port I/O, and PCI cfg space access. Also built-in
+ * are endianness conversions - to LE on write and from LE on read. */
+
+void vpm_iowrite8(struct virtio_pci_modern_device *vdev,
+                  struct virtio_pci_region *region, u8 data, size_t offset);
+
+void vpm_iowrite16(struct virtio_pci_modern_device *vdev,
+                   struct virtio_pci_region *region, u16 data, size_t offset);
+
+void vpm_iowrite32(struct virtio_pci_modern_device *vdev,
+                   struct virtio_pci_region *region, u32 data, size_t offset);
+
+static inline void vpm_iowrite64(struct virtio_pci_modern_device *vdev,
+                                 struct virtio_pci_region *region,
+                                 u64 data, size_t offset_lo, size_t offset_hi)
+{
+    vpm_iowrite32(vdev, region, (u32)data, offset_lo);
+    vpm_iowrite32(vdev, region, data >> 32, offset_hi);
+}
+
+u8 vpm_ioread8(struct virtio_pci_modern_device *vdev,
+               struct virtio_pci_region *region, size_t offset);
+
+u16 vpm_ioread16(struct virtio_pci_modern_device *vdev,
+                 struct virtio_pci_region *region, size_t offset);
+
+u32 vpm_ioread32(struct virtio_pci_modern_device *vdev,
+                 struct virtio_pci_region *region, size_t offset);
+
+/* Virtio 1.0 device manipulation routines */
+
+#define COMMON_OFFSET(field) offsetof(struct virtio_pci_common_cfg, field)
+
+static inline void vpm_reset(struct virtio_pci_modern_device *vdev)
+{
+    vpm_iowrite8(vdev, &vdev->common, 0, COMMON_OFFSET(device_status));
+    while (vpm_ioread8(vdev, &vdev->common, COMMON_OFFSET(device_status)))
+        mdelay(1);
+}
+
+static inline u8 vpm_get_status(struct virtio_pci_modern_device *vdev)
+{
+    return vpm_ioread8(vdev, &vdev->common, COMMON_OFFSET(device_status));
+}
+
+static inline void vpm_add_status(struct virtio_pci_modern_device *vdev,
+                                  u8 status)
+{
+    u8 curr_status = vpm_ioread8(vdev, &vdev->common, COMMON_OFFSET(device_status));
+    vpm_iowrite8(vdev, &vdev->common,
+                 curr_status | status, COMMON_OFFSET(device_status));
+}
+
+static inline u64 vpm_get_features(struct virtio_pci_modern_device *vdev)
+{
+    u32 features_lo, features_hi;
+
+    vpm_iowrite32(vdev, &vdev->common, 0, COMMON_OFFSET(device_feature_select));
+    features_lo = vpm_ioread32(vdev, &vdev->common, COMMON_OFFSET(device_feature));
+    vpm_iowrite32(vdev, &vdev->common, 1, COMMON_OFFSET(device_feature_select));
+    features_hi = vpm_ioread32(vdev, &vdev->common, COMMON_OFFSET(device_feature));
+
+    return ((u64)features_hi << 32) | features_lo;
+}
+
+static inline void vpm_set_features(struct virtio_pci_modern_device *vdev,
+                                    u64 features)
+{
+    u32 features_lo = (u32)features;
+    u32 features_hi = features >> 32;
+
+    vpm_iowrite32(vdev, &vdev->common, 0, COMMON_OFFSET(guest_feature_select));
+    vpm_iowrite32(vdev, &vdev->common, features_lo, COMMON_OFFSET(guest_feature));
+    vpm_iowrite32(vdev, &vdev->common, 1, COMMON_OFFSET(guest_feature_select));
+    vpm_iowrite32(vdev, &vdev->common, features_hi, COMMON_OFFSET(guest_feature));
+}
+
+static inline void vpm_get(struct virtio_pci_modern_device *vdev,
+                           unsigned offset, void *buf, unsigned len)
+{
+    u8 *ptr = buf;
+    unsigned i;
+
+    for (i = 0; i < len; i++)
+        ptr[i] = vpm_ioread8(vdev, &vdev->device, offset + i);
+}
+
+static inline u8 vpm_get_isr(struct virtio_pci_modern_device *vdev)
+{
+    return vpm_ioread8(vdev, &vdev->isr, 0);
+}
+
+void vpm_notify(struct virtio_pci_modern_device *vdev,
+                struct vring_virtqueue *vq);
+
+int vpm_find_vqs(struct virtio_pci_modern_device *vdev,
+                 unsigned nvqs, struct vring_virtqueue *vqs);
+
+int virtio_pci_find_capability(struct pci_device *pci, uint8_t cfg_type);
+
+int virtio_pci_map_capability(struct pci_device *pci, int cap, size_t minlen,
+                              u32 align, u32 start, u32 size,
+                              struct virtio_pci_region *region);
+
+void virtio_pci_unmap_capability(struct virtio_pci_region *region);
 #endif /* _VIRTIO_PCI_H_ */