[Qemu-devel] Re: [PATCH 3/3] virtio block device

[Dor Laor <dor.laor@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 2307 bytes --]

Anthony Liguori wrote:

Subject: [PATCH 3/3] virtio block device

+
+static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIOBlock *s = to_virtio_blk(vdev);
+    VirtQueueElement elem;
+    unsigned int count;
+
+    while ((count = virtqueue_pop(vq, &elem)) != 0) {
+	struct virtio_blk_inhdr *in;
+	struct virtio_blk_outhdr *out;
+	unsigned int wlen;
+	off_t off;
+	int i;
+
+	out = (void *)elem.out_sg[0].iov_base;
+	in = (void *)elem.in_sg[elem.in_num - 1].iov_base;
+	off = out->sector;
+
+	if (out->type & VIRTIO_BLK_T_SCSI_CMD) {
+	    wlen = sizeof(*in);
+	    in->status = VIRTIO_BLK_S_UNSUPP;
+	} else if (out->type & VIRTIO_BLK_T_OUT) {
+	    wlen = sizeof(*in);
+
+	    for (i = 1; i < elem.out_num; i++) {
+		bdrv_write(s->bs, off,
+			   elem.out_sg[i].iov_base,
+			   elem.out_sg[i].iov_len / 512);
+		off += elem.out_sg[i].iov_len / 512;
+	    }
+
+	    in->status = VIRTIO_BLK_S_OK;
+	} else {
+	    wlen = sizeof(*in);
+
+	    for (i = 0; i < elem.in_num - 1; i++) {
+		bdrv_read(s->bs, off,
+			  elem.in_sg[i].iov_base,
+			  elem.in_sg[i].iov_len / 512);
+		off += elem.in_sg[i].iov_len / 512;
+		wlen += elem.in_sg[i].iov_len;
+	    }
+
+	    in->status = VIRTIO_BLK_S_OK;
+	}
+
+	virtqueue_push(vq, &elem, wlen);
+	virtio_notify(vdev, vq);
+    }



The notify here should also be outside the while loop.


===================================================================
--- qemu.orig/sysemu.h	2007-12-04 13:51:49.000000000 -0600
+++ qemu/sysemu.h	2007-12-04 14:18:57.000000000 -0600
@@ -117,7 +117,7 @@
 #endif
 
 typedef enum {
-    IF_IDE, IF_SCSI, IF_FLOPPY, IF_PFLASH, IF_MTD, IF_SD
+    IF_IDE, IF_SCSI, IF_FLOPPY, IF_PFLASH, IF_MTD, IF_SD, IF_VIRTIO
 } BlockInterfaceType;
 
 typedef struct DriveInfo {
Index: qemu/hw/pc.c
===================================================================
--- qemu.orig/hw/pc.c	2007-12-04 13:51:49.000000000 -0600
+++ qemu/hw/pc.c	2007-12-04 14:18:57.000000000 -0600
@@ -1008,6 +1008,18 @@
 	    }
         }
     }
+
+    /* Add virtio block devices */
+    if (pci_enabled) {
+	int index;
+	int unit_id = 0;
+
+	while ((index = drive_get_index(IF_VIRTIO, 0, unit_id)) != -1) {
+	    virtio_blk_init(pci_bus, 0x5002, 0x2258,




The pci vendor id should be identical to the network (0x6900)
regards,
Dor.



[-- Attachment #2: Type: text/html, Size: 2847 bytes --]