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tools/lguest: don't start devices until DRIVER_OK status set.

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We were activating them with the virtqueues, and that's not allowed.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2015-02-13 17:13:42 +10:30
parent 3afe3e0f8d
commit d761b03291
1 changed files with 36 additions and 8 deletions
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44
tools/lguest/lguest.c
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@ -1688,16 +1688,15 @@ static void restore_vq_config(struct virtio_pci_common_cfg *cfg,
}
/*
* 4.1.4.3.2:
*
* The driver MUST configure the other virtqueue fields before
* enabling the virtqueue with queue_enable.
*
* When they enable the virtqueue, we check that their setup is valid.
*/
static void enable_virtqueue(struct device *d, struct virtqueue *vq)
static void check_virtqueue(struct device *d, struct virtqueue *vq)
{
/*
* Create stack for thread. Since the stack grows upwards, we point
* the stack pointer to the end of this region.
*/
char *stack = malloc(32768);
/* Because lguest is 32 bit, all the descriptor high bits must be 0 */
if (vq->pci_config.queue_desc_hi
|| vq->pci_config.queue_avail_hi
@ -1716,7 +1715,15 @@ static void enable_virtqueue(struct device *d, struct virtqueue *vq)
sizeof(*vq->vring.used)
+ (sizeof(vq->vring.used->ring[0])
* vq->vring.num));
}
static void start_virtqueue(struct virtqueue *vq)
{
/*
* Create stack for thread. Since the stack grows upwards, we point
* the stack pointer to the end of this region.
*/
char *stack = malloc(32768);
/* Create a zero-initialized eventfd. */
vq->eventfd = eventfd(0, 0);
@ -1732,6 +1739,16 @@ static void enable_virtqueue(struct device *d, struct virtqueue *vq)
err(1, "Creating clone");
}
static void start_virtqueues(struct device *d)
{
struct virtqueue *vq;
for (vq = d->vq; vq; vq = vq->next) {
if (vq->pci_config.queue_enable)
start_virtqueue(vq);
}
}
static void emulate_mmio_write(struct device *d, u32 off, u32 val, u32 mask)
{
struct virtqueue *vq;
@ -1780,6 +1797,17 @@ static void emulate_mmio_write(struct device *d, u32 off, u32 val, u32 mask)
*/
if (val == 0)
reset_device(d);
/*
* 2.1.2:
*
* The device MUST NOT consume buffers or notify the driver
* before DRIVER_OK.
*/
if (val & VIRTIO_CONFIG_S_DRIVER_OK
&& !(d->mmio->cfg.device_status & VIRTIO_CONFIG_S_DRIVER_OK))
start_virtqueues(d);
goto write_through8;
case offsetof(struct virtio_pci_mmio, cfg.queue_select):
vq = vq_by_num(d, val);
@ -1833,7 +1861,7 @@ static void emulate_mmio_write(struct device *d, u32 off, u32 val, u32 mask)
* The driver MUST configure the other virtqueue fields before
* enabling the virtqueue with queue_enable.
*/
enable_virtqueue(d, vq_by_num(d, d->mmio->cfg.queue_select));
check_virtqueue(d, vq_by_num(d, d->mmio->cfg.queue_select));
goto write_through16;
case offsetof(struct virtio_pci_mmio, cfg.queue_notify_off):
errx(1, "%s: attempt to write to queue_notify_off", d->name);