Virtio core support

This patch adds core support for VirtIO.  VirtIO is a paravirtualization
framework that has been in Linux since 2.6.21.  A PCI transport has been
available since 2.6.25.  Network drivers are also available for Windows.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5869 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 121 insertions, 0 deletions

diff --git a/hw/virtio.h b/hw/virtio.h
new file mode 100644
index 0000000..f04e75f
--- /dev/null
+++ b/hw/virtio.h
@@ -0,0 +1,121 @@
+/*
+ * Virtio Support
+ *
+ * Copyright IBM, Corp. 2007
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef _QEMU_VIRTIO_H
+#define _QEMU_VIRTIO_H
+
+#include <sys/uio.h>
+#include "hw.h"
+#include "pci.h"
+
+/* from Linux's linux/virtio_config.h */
+
+/* Status byte for guest to report progress, and synchronize features. */
+/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
+#define VIRTIO_CONFIG_S_ACKNOWLEDGE     1
+/* We have found a driver for the device. */
+#define VIRTIO_CONFIG_S_DRIVER          2
+/* Driver has used its parts of the config, and is happy */
+#define VIRTIO_CONFIG_S_DRIVER_OK       4
+/* We've given up on this device. */
+#define VIRTIO_CONFIG_S_FAILED          0x80
+
+/* We notify when the ring is completely used, even if the guest is supressing
+ * callbacks */
+#define VIRTIO_F_NOTIFY_ON_EMPTY        24
+
+/* from Linux's linux/virtio_ring.h */
+
+/* This marks a buffer as continuing via the next field. */
+#define VRING_DESC_F_NEXT       1
+/* This marks a buffer as write-only (otherwise read-only). */
+#define VRING_DESC_F_WRITE      2
+
+/* This means don't notify other side when buffer added. */
+#define VRING_USED_F_NO_NOTIFY  1
+/* This means don't interrupt guest when buffer consumed. */
+#define VRING_AVAIL_F_NO_INTERRUPT      1
+
+struct VirtQueue;
+
+typedef struct VirtQueue VirtQueue;
+typedef struct VirtIODevice VirtIODevice;
+
+#define VIRTQUEUE_MAX_SIZE 1024
+
+typedef struct VirtQueueElement
+{
+    unsigned int index;
+    unsigned int out_num;
+    unsigned int in_num;
+    target_phys_addr_t in_addr[VIRTQUEUE_MAX_SIZE];
+    struct iovec in_sg[VIRTQUEUE_MAX_SIZE];
+    struct iovec out_sg[VIRTQUEUE_MAX_SIZE];
+} VirtQueueElement;
+
+#define VIRTIO_PCI_QUEUE_MAX 16
+
+struct VirtIODevice
+{
+    PCIDevice pci_dev;
+    const char *name;
+    uint32_t addr;
+    uint8_t status;
+    uint8_t isr;
+    uint16_t queue_sel;
+    uint32_t features;
+    size_t config_len;
+    void *config;
+    uint32_t (*get_features)(VirtIODevice *vdev);
+    void (*set_features)(VirtIODevice *vdev, uint32_t val);
+    void (*get_config)(VirtIODevice *vdev, uint8_t *config);
+    void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
+    void (*reset)(VirtIODevice *vdev);
+    VirtQueue *vq;
+};
+
+VirtIODevice *virtio_init_pci(PCIBus *bus, const char *name,
+                              uint16_t vendor, uint16_t device,
+                              uint16_t subvendor, uint16_t subdevice,
+                              uint8_t class_code, uint8_t subclass_code,
+                              uint8_t pif, size_t config_size,
+                              size_t struct_size);
+
+VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
+                            void (*handle_output)(VirtIODevice *,
+                                                  VirtQueue *));
+
+void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
+                    unsigned int len);
+void virtqueue_flush(VirtQueue *vq, unsigned int count);
+void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
+                    unsigned int len, unsigned int idx);
+
+int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem);
+int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes);
+
+void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
+
+void virtio_save(VirtIODevice *vdev, QEMUFile *f);
+
+void virtio_load(VirtIODevice *vdev, QEMUFile *f);
+
+void virtio_notify_config(VirtIODevice *vdev);
+
+void virtio_queue_set_notification(VirtQueue *vq, int enable);
+
+int virtio_queue_ready(VirtQueue *vq);
+
+int virtio_queue_empty(VirtQueue *vq);
+
+#endif