Move the logic for attaching a descriptor to its own function.

Signed-off-by: Andrew Scull ascull@google.com --- drivers/virtio/virtio_ring.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index a6922ce1b8..8e0cb3d666 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -16,6 +16,18 @@ #include <linux/bug.h> #include <linux/compat.h>

+static unsigned int virtqueue_attach_desc(struct virtqueue *vq, unsigned int i, + struct virtio_sg *sg, u16 flags) +{ + struct vring_desc *desc = &vq->vring.desc[i]; + + desc->addr = cpu_to_virtio64(vq->vdev, (u64)(uintptr_t)sg->addr); + desc->len = cpu_to_virtio32(vq->vdev, sg->length); + desc->flags = cpu_to_virtio16(vq->vdev, flags); + + return virtio16_to_cpu(vq->vdev, desc->next); +} + int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[], unsigned int out_sgs, unsigned int in_sgs) { @@ -45,26 +57,14 @@ int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[], }

for (n = 0; n < out_sgs; n++) { - struct virtio_sg *sg = sgs[n]; - - desc[i].flags = cpu_to_virtio16(vq->vdev, VRING_DESC_F_NEXT); - desc[i].addr = cpu_to_virtio64(vq->vdev, (u64)(size_t)sg->addr); - desc[i].len = cpu_to_virtio32(vq->vdev, sg->length); - prev = i; - i = virtio16_to_cpu(vq->vdev, desc[i].next); + i = virtqueue_attach_desc(vq, i, sgs[n], VRING_DESC_F_NEXT); } for (; n < (out_sgs + in_sgs); n++) { - struct virtio_sg *sg = sgs[n]; - - desc[i].flags = cpu_to_virtio16(vq->vdev, VRING_DESC_F_NEXT | - VRING_DESC_F_WRITE); - desc[i].addr = cpu_to_virtio64(vq->vdev, - (u64)(uintptr_t)sg->addr); - desc[i].len = cpu_to_virtio32(vq->vdev, sg->length); + u16 flags = VRING_DESC_F_NEXT | VRING_DESC_F_WRITE;

prev = i; - i = virtio16_to_cpu(vq->vdev, desc[i].next); + i = virtqueue_attach_desc(vq, i, sgs[n], flags); } /* Last one doesn't continue */ desc[prev].flags &= cpu_to_virtio16(vq->vdev, ~VRING_DESC_F_NEXT);

The shared descriptors should only be written by the guest driver, however, the device is still able to overwrite and corrupt them. Maintain a private shadow copy of the descriptors for the driver to use for state tracking, removing the need to read from the shared descriptors.

Signed-off-by: Andrew Scull ascull@google.com --- drivers/virtio/virtio_ring.c | 49 ++++++++++++++++++++++++------------ include/virtio_ring.h | 10 ++++++++ 2 files changed, 43 insertions(+), 16 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 8e0cb3d666..69fd8c6aa0 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -19,13 +19,21 @@ static unsigned int virtqueue_attach_desc(struct virtqueue *vq, unsigned int i, struct virtio_sg *sg, u16 flags) { + struct vring_desc_shadow *desc_shadow = &vq->vring_desc_shadow[i]; struct vring_desc *desc = &vq->vring.desc[i];

- desc->addr = cpu_to_virtio64(vq->vdev, (u64)(uintptr_t)sg->addr); - desc->len = cpu_to_virtio32(vq->vdev, sg->length); - desc->flags = cpu_to_virtio16(vq->vdev, flags); + /* Update the shadow descriptor. */ + desc_shadow->addr = (u64)(uintptr_t)sg->addr; + desc_shadow->len = sg->length; + desc_shadow->flags = flags;

- return virtio16_to_cpu(vq->vdev, desc->next); + /* Update the shared descriptor to match the shadow. */ + desc->addr = cpu_to_virtio64(vq->vdev, desc_shadow->addr); + desc->len = cpu_to_virtio32(vq->vdev, desc_shadow->len); + desc->flags = cpu_to_virtio16(vq->vdev, desc_shadow->flags); + desc->next = cpu_to_virtio16(vq->vdev, desc_shadow->next); + + return desc_shadow->next; }

int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[], @@ -67,7 +75,8 @@ int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[], i = virtqueue_attach_desc(vq, i, sgs[n], flags); } /* Last one doesn't continue */ - desc[prev].flags &= cpu_to_virtio16(vq->vdev, ~VRING_DESC_F_NEXT); + vq->vring_desc_shadow[prev].flags &= ~VRING_DESC_F_NEXT; + desc[prev].flags = cpu_to_virtio16(vq->vdev, vq->vring_desc_shadow[prev].flags);

/* We're using some buffers from the free list. */ vq->num_free -= descs_used; @@ -136,17 +145,16 @@ void virtqueue_kick(struct virtqueue *vq) static void detach_buf(struct virtqueue *vq, unsigned int head) { unsigned int i; - __virtio16 nextflag = cpu_to_virtio16(vq->vdev, VRING_DESC_F_NEXT);

/* Put back on free list: unmap first-level descriptors and find end */ i = head;

- while (vq->vring.desc[i].flags & nextflag) { - i = virtio16_to_cpu(vq->vdev, vq->vring.desc[i].next); + while (vq->vring_desc_shadow[i].flags & VRING_DESC_F_NEXT) { + i = vq->vring_desc_shadow[i].next; vq->num_free++; }

- vq->vring.desc[i].next = cpu_to_virtio16(vq->vdev, vq->free_head); + vq->vring_desc_shadow[i].next = vq->free_head; vq->free_head = head;

/* Plus final descriptor */ @@ -199,8 +207,7 @@ void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len) virtio_store_mb(&vring_used_event(&vq->vring), cpu_to_virtio16(vq->vdev, vq->last_used_idx));

- return (void *)(uintptr_t)virtio64_to_cpu(vq->vdev, - vq->vring.desc[i].addr); + return (void *)(uintptr_t)vq->vring_desc_shadow[i].addr; }

static struct virtqueue *__vring_new_virtqueue(unsigned int index, @@ -209,6 +216,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index, { unsigned int i; struct virtqueue *vq; + struct vring_desc_shadow *vring_desc_shadow; struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev); struct udevice *vdev = uc_priv->vdev;

@@ -216,10 +224,17 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index, if (!vq) return NULL;

+ vring_desc_shadow = calloc(vring.num, sizeof(struct vring_desc_shadow)); + if (!vring_desc_shadow) { + free(vq); + return NULL; + } + vq->vdev = vdev; vq->index = index; vq->num_free = vring.num; vq->vring = vring; + vq->vring_desc_shadow = vring_desc_shadow; vq->last_used_idx = 0; vq->avail_flags_shadow = 0; vq->avail_idx_shadow = 0; @@ -237,7 +252,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index, /* Put everything in free lists */ vq->free_head = 0; for (i = 0; i < vring.num - 1; i++) - vq->vring.desc[i].next = cpu_to_virtio16(vdev, i + 1); + vq->vring_desc_shadow[i].next = i + 1;

return vq; } @@ -290,6 +305,7 @@ struct virtqueue *vring_create_virtqueue(unsigned int index, unsigned int num, void vring_del_virtqueue(struct virtqueue *vq) { free(vq->vring.desc); + free(vq->vring_desc_shadow); list_del(&vq->list); free(vq); } @@ -335,11 +351,12 @@ void virtqueue_dump(struct virtqueue *vq) printf("\tlast_used_idx %u, avail_flags_shadow %u, avail_idx_shadow %u\n", vq->last_used_idx, vq->avail_flags_shadow, vq->avail_idx_shadow);

- printf("Descriptor dump:\n"); + printf("Shadow descriptor dump:\n"); for (i = 0; i < vq->vring.num; i++) { - printf("\tdesc[%u] = { 0x%llx, len %u, flags %u, next %u }\n", - i, vq->vring.desc[i].addr, vq->vring.desc[i].len, - vq->vring.desc[i].flags, vq->vring.desc[i].next); + struct vring_desc_shadow *desc = &vq->vring_desc_shadow[i]; + + printf("\tdesc_shadow[%u] = { 0x%llx, len %u, flags %u, next %u }\n", + i, desc->addr, desc->len, desc->flags, desc->next); }

printf("Avail ring dump:\n"); diff --git a/include/virtio_ring.h b/include/virtio_ring.h index 6fc0593b14..52cbe77c0a 100644 --- a/include/virtio_ring.h +++ b/include/virtio_ring.h @@ -55,6 +55,14 @@ struct vring_desc { __virtio16 next; };

+/* Shadow of struct vring_desc in guest byte order. */ +struct vring_desc_shadow { + u64 addr; + u32 len; + u16 flags; + u16 next; +}; + struct vring_avail { __virtio16 flags; __virtio16 idx; @@ -89,6 +97,7 @@ struct vring { * @index: the zero-based ordinal number for this queue * @num_free: number of elements we expect to be able to fit * @vring: actual memory layout for this queue + * @vring_desc_shadow: guest-only copy of descriptors * @event: host publishes avail event idx * @free_head: head of free buffer list * @num_added: number we've added since last sync @@ -102,6 +111,7 @@ struct virtqueue { unsigned int index; unsigned int num_free; struct vring vring; + struct vring_desc_shadow *vring_desc_shadow; bool event; unsigned int free_head; unsigned int num_added;

When the device returns used buffers, it should refer to the descriptor that is the head of the descriptor chain for that buffer. Confirm this to be the case by tracking the head of descriptor chains that have been made available to the device.

Signed-off-by: Andrew Scull ascull@google.com --- drivers/virtio/virtio_ring.c | 12 ++++++++++++ include/virtio_ring.h | 2 ++ 2 files changed, 14 insertions(+)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 69fd8c6aa0..383d574cb0 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -84,6 +84,9 @@ int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[], /* Update free pointer */ vq->free_head = i;

+ /* Mark the descriptor as the head of a chain. */ + vq->vring_desc_shadow[head].chain_head = true; + /* * Put entry in available array (but don't update avail->idx * until they do sync). @@ -146,6 +149,9 @@ static void detach_buf(struct virtqueue *vq, unsigned int head) { unsigned int i;

+ /* Unmark the descriptor as the head of a chain. */ + vq->vring_desc_shadow[head].chain_head = false; + /* Put back on free list: unmap first-level descriptors and find end */ i = head;

@@ -196,6 +202,12 @@ void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len) return NULL; }

+ if (unlikely(!vq->vring_desc_shadow[i].chain_head)) { + printf("(%s.%d): id %u is not a head\n", + vq->vdev->name, vq->index, i); + return NULL; + } + detach_buf(vq, i); vq->last_used_idx++; /* diff --git a/include/virtio_ring.h b/include/virtio_ring.h index 52cbe77c0a..c77c212cff 100644 --- a/include/virtio_ring.h +++ b/include/virtio_ring.h @@ -61,6 +61,8 @@ struct vring_desc_shadow { u32 len; u16 flags; u16 next; + /* Metadata about the descriptor. */ + bool chain_head; };

struct vring_avail {

The virtio ring is the basis of virtio communication. Test its basic functionality and its resilience against corruption from the device.

Signed-off-by: Andrew Scull ascull@google.com --- test/dm/virtio.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+)

diff --git a/test/dm/virtio.c b/test/dm/virtio.c index 9a7e658cce..4cf0f56260 100644 --- a/test/dm/virtio.c +++ b/test/dm/virtio.c @@ -130,3 +130,75 @@ static int dm_test_virtio_remove(struct unit_test_state *uts) return 0; } DM_TEST(dm_test_virtio_remove, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT); + +/* Test all of the virtio ring */ +static int dm_test_virtio_ring(struct unit_test_state *uts) +{ + struct udevice *bus, *dev; + struct virtio_dev_priv *uc_priv; + struct virtqueue *vq; + struct virtio_sg sg[2]; + struct virtio_sg *sgs[2]; + unsigned int len; + u8 buffer[2][32]; + + /* check probe success */ + ut_assertok(uclass_first_device(UCLASS_VIRTIO, &bus)); + ut_assertnonnull(bus); + + /* check the child virtio-rng device is bound */ + ut_assertok(device_find_first_child(bus, &dev)); + ut_assertnonnull(dev); + + /* + * fake the virtio device probe by filling in uc_priv->vdev + * which is used by virtio_find_vqs/virtio_del_vqs. + */ + uc_priv = dev_get_uclass_priv(bus); + ut_assertnonnull(uc_priv); + uc_priv->vdev = dev; + + /* prepare the scatter-gather buffer */ + sg[0].addr = buffer[0]; + sg[0].length = sizeof(buffer[0]); + sg[1].addr = buffer[1]; + sg[1].length = sizeof(buffer[1]); + sgs[0] = &sg[0]; + sgs[1] = &sg[1]; + + /* read a buffer and report written size from device */ + ut_assertok(virtio_find_vqs(dev, 1, &vq)); + ut_assertok(virtqueue_add(vq, sgs, 0, 1)); + vq->vring.used->idx = 1; + vq->vring.used->ring[0].id = 0; + vq->vring.used->ring[0].len = 0x53355885; + ut_asserteq_ptr(buffer, virtqueue_get_buf(vq, &len)); + ut_asserteq(0x53355885, len); + ut_assertok(virtio_del_vqs(dev)); + + /* rejects used descriptors that aren't a chain head */ + ut_assertok(virtio_find_vqs(dev, 1, &vq)); + ut_assertok(virtqueue_add(vq, sgs, 0, 2)); + vq->vring.used->idx = 1; + vq->vring.used->ring[0].id = 1; + vq->vring.used->ring[0].len = 0x53355885; + ut_assertnull(virtqueue_get_buf(vq, &len)); + ut_assertok(virtio_del_vqs(dev)); + + /* device changes to descriptor are ignored */ + ut_assertok(virtio_find_vqs(dev, 1, &vq)); + ut_assertok(virtqueue_add(vq, sgs, 0, 1)); + vq->vring.desc[0].addr = cpu_to_virtio64(dev, 0xbadbad11); + vq->vring.desc[0].len = cpu_to_virtio32(dev, 0x11badbad); + vq->vring.desc[0].flags = cpu_to_virtio16(dev, VRING_DESC_F_NEXT); + vq->vring.desc[0].next = cpu_to_virtio16(dev, U16_MAX); + vq->vring.used->idx = 1; + vq->vring.used->ring[0].id = 0; + vq->vring.used->ring[0].len = 6; + ut_asserteq_ptr(buffer, virtqueue_get_buf(vq, &len)); + ut_asserteq(6, len); + ut_assertok(virtio_del_vqs(dev)); + + return 0; +} +DM_TEST(dm_test_virtio_ring, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);

The virtio sandbox transport was setting the device features value to the bit index rather than shifting a bit to the right index. Fix this using the bit manipulation macros.

Signed-off-by: Andrew Scull ascull@google.com --- drivers/virtio/virtio_sandbox.c | 2 +- test/dm/virtio.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/virtio/virtio_sandbox.c b/drivers/virtio/virtio_sandbox.c index aafb7beb94..a73b123454 100644 --- a/drivers/virtio/virtio_sandbox.c +++ b/drivers/virtio/virtio_sandbox.c @@ -160,7 +160,7 @@ static int virtio_sandbox_probe(struct udevice *udev) struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);

/* fake some information for testing */ - priv->device_features = VIRTIO_F_VERSION_1; + priv->device_features = BIT_ULL(VIRTIO_F_VERSION_1); uc_priv->device = VIRTIO_ID_BLOCK; uc_priv->vendor = ('u' << 24) | ('b' << 16) | ('o' << 8) | 't';

diff --git a/test/dm/virtio.c b/test/dm/virtio.c index 4cf0f56260..63fcc22172 100644 --- a/test/dm/virtio.c +++ b/test/dm/virtio.c @@ -77,7 +77,7 @@ static int dm_test_virtio_all_ops(struct unit_test_state *uts) ut_assertok(virtio_get_status(dev, &status)); ut_asserteq(0, status); ut_assertok(virtio_get_features(dev, &features)); - ut_asserteq(VIRTIO_F_VERSION_1, features); + ut_asserteq_64(BIT_ULL(VIRTIO_F_VERSION_1), features); ut_assertok(virtio_set_features(dev)); ut_assertok(virtio_find_vqs(dev, nvqs, vqs)); ut_assertok(virtio_del_vqs(dev));

The virtqueue is passed to virtio_notify() so move the virtqueue deletion to the end of the test when it's no longer needed. This wasn't causing any problems because the sandbox virtio transport driver doesn't do anything for notifications, but it could cause problems if things change and it was a bad example.

Signed-off-by: Andrew Scull ascull@google.com --- test/dm/virtio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/dm/virtio.c b/test/dm/virtio.c index 63fcc22172..d054ccfaa4 100644 --- a/test/dm/virtio.c +++ b/test/dm/virtio.c @@ -80,8 +80,8 @@ static int dm_test_virtio_all_ops(struct unit_test_state *uts) ut_asserteq_64(BIT_ULL(VIRTIO_F_VERSION_1), features); ut_assertok(virtio_set_features(dev)); ut_assertok(virtio_find_vqs(dev, nvqs, vqs)); - ut_assertok(virtio_del_vqs(dev)); ut_assertok(virtio_notify(dev, vqs[0])); + ut_assertok(virtio_del_vqs(dev));

return 0; }

The virtio-rng driver is extremely simple, making it suitable for testing more of the virtio uclass logic. Have the sandbox driver bind the virtio-rng driver rather than the virtio-blk driver so it can be used in tests.

Signed-off-by: Andrew Scull ascull@google.com --- drivers/virtio/virtio_sandbox.c | 2 +- test/dm/virtio.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/virtio/virtio_sandbox.c b/drivers/virtio/virtio_sandbox.c index a73b123454..5484ae3a1a 100644 --- a/drivers/virtio/virtio_sandbox.c +++ b/drivers/virtio/virtio_sandbox.c @@ -161,7 +161,7 @@ static int virtio_sandbox_probe(struct udevice *udev)

/* fake some information for testing */ priv->device_features = BIT_ULL(VIRTIO_F_VERSION_1); - uc_priv->device = VIRTIO_ID_BLOCK; + uc_priv->device = VIRTIO_ID_RNG; uc_priv->vendor = ('u' << 24) | ('b' << 16) | ('o' << 8) | 't';

return 0; diff --git a/test/dm/virtio.c b/test/dm/virtio.c index d054ccfaa4..769945a0d8 100644 --- a/test/dm/virtio.c +++ b/test/dm/virtio.c @@ -25,10 +25,10 @@ static int dm_test_virtio_base(struct unit_test_state *uts) ut_assertok(uclass_first_device(UCLASS_VIRTIO, &bus)); ut_assertnonnull(bus);

- /* check the child virtio-blk device is bound */ + /* check the child virtio-rng device is bound */ ut_assertok(device_find_first_child(bus, &dev)); ut_assertnonnull(dev); - ut_assertok(strcmp(dev->name, "virtio-blk#0")); + ut_asserteq_str("virtio-rng#0", dev->name);

/* check driver status */ ut_assertok(virtio_get_status(dev, &status)); @@ -54,7 +54,7 @@ static int dm_test_virtio_all_ops(struct unit_test_state *uts) ut_assertok(uclass_first_device(UCLASS_VIRTIO, &bus)); ut_assertnonnull(bus);

- /* check the child virtio-blk device is bound */ + /* check the child virtio-rng device is bound */ ut_assertok(device_find_first_child(bus, &dev)); ut_assertnonnull(dev);

@@ -114,7 +114,7 @@ static int dm_test_virtio_remove(struct unit_test_state *uts) ut_assertok(uclass_first_device(UCLASS_VIRTIO, &bus)); ut_assertnonnull(bus);

- /* check the child virtio-blk device is bound */ + /* check the child virtio-rng device is bound */ ut_assertok(device_find_first_child(bus, &dev)); ut_assertnonnull(dev);

Once the virtio-rng driver has been bound, probe it to trigger the pre and post child probe hooks of the virtio uclass driver. Check the status of the virtio device to confirm it reached the expected state.

Signed-off-by: Andrew Scull ascull@google.com --- test/dm/virtio.c | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/test/dm/virtio.c b/test/dm/virtio.c index 769945a0d8..7139c31ab5 100644 --- a/test/dm/virtio.c +++ b/test/dm/virtio.c @@ -34,6 +34,15 @@ static int dm_test_virtio_base(struct unit_test_state *uts) ut_assertok(virtio_get_status(dev, &status)); ut_asserteq(VIRTIO_CONFIG_S_ACKNOWLEDGE, status);

+ /* probe the virtio-rng driver */ + ut_assertok(device_probe(dev)); + + /* check the device was reset and the driver picked up the device */ + ut_assertok(virtio_get_status(dev, &status)); + ut_asserteq(VIRTIO_CONFIG_S_DRIVER | + VIRTIO_CONFIG_S_DRIVER_OK | + VIRTIO_CONFIG_S_FEATURES_OK, status); + return 0; } DM_TEST(dm_test_virtio_base, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);

Check the length of data written by the device is consistent with the size of the buffers to avoid out-of-bounds memory accesses in case values aren't consistent.

Signed-off-by: Andrew Scull ascull@google.com Cc: Sughosh Ganu sughosh.ganu@linaro.org --- drivers/virtio/virtio_rng.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c index 9314c0a03e..b85545c2ee 100644 --- a/drivers/virtio/virtio_rng.c +++ b/drivers/virtio/virtio_rng.c @@ -41,6 +41,9 @@ static int virtio_rng_read(struct udevice *dev, void *data, size_t len) while (!virtqueue_get_buf(priv->rng_vq, &rsize)) ;

+ if (rsize > sg.length) + return -EIO; + memcpy(ptr, buf, rsize); len -= rsize; ptr += rsize;

When looking into possibilities for testing virtio drivers I was trying to simulate the device's responses in the virtqueue. It required a hack to get access to the virtqueue by accessing the driver's private data and only allows pre-programmed buffer returns but no dynamic responses, data or descriptor modifications.

This is an example of a regression test for the virtio-rng fix in the previous patch.

Signed-off-by: Andrew Scull ascull@google.com --- test/dm/virtio.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+)

diff --git a/test/dm/virtio.c b/test/dm/virtio.c index 7139c31ab5..85791e3f58 100644 --- a/test/dm/virtio.c +++ b/test/dm/virtio.c @@ -12,6 +12,7 @@ #include <dm/root.h> #include <dm/test.h> #include <dm/uclass-internal.h> +#include <rng.h> #include <test/test.h> #include <test/ut.h>

@@ -211,3 +212,38 @@ static int dm_test_virtio_ring(struct unit_test_state *uts) return 0; } DM_TEST(dm_test_virtio_ring, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT); + +struct virtio_rng_priv { + struct virtqueue *rng_vq; +}; + +/* Test the virtio-rng driver validates the used size */ +static int dm_test_virtio_rng(struct unit_test_state *uts) +{ + struct udevice *bus, *dev; + struct virtio_rng_priv *priv; + u8 buffer[16]; + + /* check probe success */ + ut_assertok(uclass_first_device(UCLASS_VIRTIO, &bus)); + ut_assertnonnull(bus); + + /* check the child virtio-rng device is bound */ + ut_assertok(device_find_first_child(bus, &dev)); + ut_assertnonnull(dev); + + /* probe the virtio-rng driver */ + ut_assertok(device_probe(dev)); + + /* simulate the device returning the buffer with too much data */ + priv = dev_get_priv(dev); + priv->rng_vq->vring.used->idx = 1; + priv->rng_vq->vring.used->ring[0].id = 0; + priv->rng_vq->vring.used->ring[0].len = U32_MAX; + + /* check the driver gracefully handles the error */ + ut_asserteq(-EIO, dm_rng_read(dev, buffer, sizeof(buffer))); + + return 0; +} +DM_TEST(dm_test_virtio_rng, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);