1 files changed, 41 insertions, 21 deletions

diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index 4c1fc65a8b3d..3be8ab2a886a 100644
--- a/Documentation/lguest/lguest.c
+++ b/Documentation/lguest/lguest.c
@@ -131,6 +131,9 @@ struct device
         /* Any queues attached to this device */
         struct virtqueue *vq;
 
+        /* Handle status being finalized (ie. feature bits stable). */
+        void (*ready)(struct device *me);
+
         /* Device-specific data. */
         void *priv;
 };
@@ -925,24 +928,40 @@ static void enable_fd(int fd, struct virtqueue *vq)
         write(waker_fd, &vq->dev->fd, sizeof(vq->dev->fd));
 }
 
-/* When the Guest asks us to reset a device, it's is fairly easy. */
-static void reset_device(struct device *dev)
+/* When the Guest tells us they updated the status field, we handle it. */
+static void update_device_status(struct device *dev)
 {
         struct virtqueue *vq;
 
-        verbose("Resetting device %s\n", dev->name);
-        /* Clear the status. */
-        dev->desc->status = 0;
+        /* This is a reset. */
+        if (dev->desc->status == 0) {
+                verbose("Resetting device %s\n", dev->name);
 
-        /* Clear any features they've acked. */
-        memset(get_feature_bits(dev) + dev->desc->feature_len, 0,
-               dev->desc->feature_len);
+                /* Clear any features they've acked. */
+                memset(get_feature_bits(dev) + dev->desc->feature_len, 0,
+                       dev->desc->feature_len);
 
-        /* Zero out the virtqueues. */
-        for (vq = dev->vq; vq; vq = vq->next) {
-                memset(vq->vring.desc, 0,
-                       vring_size(vq->config.num, getpagesize()));
-                vq->last_avail_idx = 0;
+                /* Zero out the virtqueues. */
+                for (vq = dev->vq; vq; vq = vq->next) {
+                        memset(vq->vring.desc, 0,
+                               vring_size(vq->config.num, getpagesize()));
+                        vq->last_avail_idx = 0;
+                }
+        } else if (dev->desc->status & VIRTIO_CONFIG_S_FAILED) {
+                warnx("Device %s configuration FAILED", dev->name);
+        } else if (dev->desc->status & VIRTIO_CONFIG_S_DRIVER_OK) {
+                unsigned int i;
+
+                verbose("Device %s OK: offered", dev->name);
+                for (i = 0; i < dev->desc->feature_len; i++)
+                        verbose(" %08x", get_feature_bits(dev)[i]);
+                verbose(", accepted");
+                for (i = 0; i < dev->desc->feature_len; i++)
+                        verbose(" %08x", get_feature_bits(dev)
+                                [dev->desc->feature_len+i]);
+
+                if (dev->ready)
+                        dev->ready(dev);
         }
 }
 
@@ -954,9 +973,9 @@ static void handle_output(int fd, unsigned long addr)
 
         /* Check each device and virtqueue. */
         for (i = devices.dev; i; i = i->next) {
-                /* Notifications to device descriptors reset the device. */
+                /* Notifications to device descriptors update device status. */
                 if (from_guest_phys(addr) == i->desc) {
-                        reset_device(i);
+                        update_device_status(i);
                         return;
                 }
 
@@ -1170,6 +1189,7 @@ static struct device *new_device(const char *name, u16 type, int fd,
         dev->handle_input = handle_input;
         dev->name = name;
         dev->vq = NULL;
+        dev->ready = NULL;
 
         /* Append to device list.  Prepending to a single-linked list is
          * easier, but the user expects the devices to be arranged on the bus
@@ -1398,7 +1418,7 @@ static bool service_io(struct device *dev)
         struct vblk_info *vblk = dev->priv;
         unsigned int head, out_num, in_num, wlen;
         int ret;
-        struct virtio_blk_inhdr *in;
+        u8 *in;
         struct virtio_blk_outhdr *out;
         struct iovec iov[dev->vq->vring.num];
         off64_t off;
@@ -1416,7 +1436,7 @@ static bool service_io(struct device *dev)
                      head, out_num, in_num);
 
         out = convert(&iov[0], struct virtio_blk_outhdr);
-        in = convert(&iov[out_num+in_num-1], struct virtio_blk_inhdr);
+        in = convert(&iov[out_num+in_num-1], u8);
         off = out->sector * 512;
 
         /* The block device implements "barriers", where the Guest indicates
@@ -1430,7 +1450,7 @@ static bool service_io(struct device *dev)
          * It'd be nice if we supported eject, for example, but we don't. */
         if (out->type & VIRTIO_BLK_T_SCSI_CMD) {
                 fprintf(stderr, "Scsi commands unsupported\n");
-                in->status = VIRTIO_BLK_S_UNSUPP;
+                *in = VIRTIO_BLK_S_UNSUPP;
                 wlen = sizeof(*in);
         } else if (out->type & VIRTIO_BLK_T_OUT) {
                 /* Write */
@@ -1453,7 +1473,7 @@ static bool service_io(struct device *dev)
                         errx(1, "Write past end %llu+%u", off, ret);
                 }
                 wlen = sizeof(*in);
-                in->status = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
+                *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
         } else {
                 /* Read */
 
@@ -1466,10 +1486,10 @@ static bool service_io(struct device *dev)
                 verbose("READ from sector %llu: %i\n", out->sector, ret);
                 if (ret >= 0) {
                         wlen = sizeof(*in) + ret;
-                        in->status = VIRTIO_BLK_S_OK;
+                        *in = VIRTIO_BLK_S_OK;
                 } else {
                         wlen = sizeof(*in);
-                        in->status = VIRTIO_BLK_S_IOERR;
+                        *in = VIRTIO_BLK_S_IOERR;
                 }
         }