Ensure that elements of the callbacks array that correspond to unavailable features are set to NULL; previously, they would be left uninitialized.
Since the corresponding names array elements were explicitly set to NULL, the uninitialized callback pointers would not actually be dereferenced; however, the uninitialized callbacks elements would still be read in vp_find_vqs_msix() and used to calculate the number of MSI-X vectors required.
Cc: stable@vger.kernel.org Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Reviewed-by: Cornelia Huck cohuck@redhat.com Signed-off-by: Daniel Verkamp dverkamp@chromium.org ---
v1: https://lists.linuxfoundation.org/pipermail/virtualization/2019-December/044...
Changes from v1: - Clarified "array" in commit message to "callbacks array"
drivers/virtio/virtio_balloon.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 93f995f6cf36..8e400ece9273 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -475,7 +475,9 @@ static int init_vqs(struct virtio_balloon *vb) names[VIRTIO_BALLOON_VQ_INFLATE] = "inflate"; callbacks[VIRTIO_BALLOON_VQ_DEFLATE] = balloon_ack; names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate"; + callbacks[VIRTIO_BALLOON_VQ_STATS] = NULL; names[VIRTIO_BALLOON_VQ_STATS] = NULL; + callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
VQs without a name specified are not valid; they are skipped in the later loop that assigns MSI-X vectors to queues, but the per_vq_vectors loop above that counts the required number of vectors previously still counted any queue with a non-NULL callback as needing a vector.
Add a check to the per_vq_vectors loop so that vectors with no name are not counted to make the two loops consistent. This prevents over-counting unnecessary vectors (e.g. for features which were not negotiated with the device).
Cc: stable@vger.kernel.org Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Reviewed-by: Cornelia Huck cohuck@redhat.com Signed-off-by: Daniel Verkamp dverkamp@chromium.org ---
v1: https://lists.linuxfoundation.org/pipermail/virtualization/2019-December/044...
drivers/virtio/virtio_pci_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c index f2862f66c2ac..222d630c41fc 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -294,7 +294,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs, /* Best option: one for change interrupt, one per vq. */ nvectors = 1; for (i = 0; i < nvqs; ++i) - if (callbacks[i]) + if (names[i] && callbacks[i]) ++nvectors; } else { /* Second best: one for change, shared for all vqs. */
On Saturday, January 4, 2020 2:41 AM, Daniel Verkamp wrote:
Subject: [PATCH v2 2/2] virtio-pci: check name when counting MSI-X vectors
VQs without a name specified are not valid; they are skipped in the later loop that assigns MSI-X vectors to queues, but the per_vq_vectors loop above that counts the required number of vectors previously still counted any queue with a non-NULL callback as needing a vector.
Add a check to the per_vq_vectors loop so that vectors with no name are not counted to make the two loops consistent. This prevents over-counting unnecessary vectors (e.g. for features which were not negotiated with the device).
Cc: stable@vger.kernel.org Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Reviewed-by: Cornelia Huck cohuck@redhat.com Signed-off-by: Daniel Verkamp dverkamp@chromium.org
v1: https://lists.linuxfoundation.org/pipermail/virtualization/2019-December/044... 28.html
drivers/virtio/virtio_pci_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c index f2862f66c2ac..222d630c41fc 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -294,7 +294,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs, /* Best option: one for change interrupt, one per vq. */ nvectors = 1; for (i = 0; i < nvqs; ++i)
if (callbacks[i])
if (names[i] && callbacks[i]) ++nvectors;-- 2.24.1.735.g03f4e72817-goog
Reviewed-by: Wang, Wei W wei.w.wang@intel.com
Best, Wei
On Saturday, January 4, 2020 2:41 AM, Daniel Verkamp wrote:
Subject: [PATCH v2 1/2] virtio-balloon: initialize all vq callbacks
Ensure that elements of the callbacks array that correspond to unavailable features are set to NULL; previously, they would be left uninitialized.
Since the corresponding names array elements were explicitly set to NULL, the uninitialized callback pointers would not actually be dereferenced; however, the uninitialized callbacks elements would still be read in vp_find_vqs_msix() and used to calculate the number of MSI-X vectors required.
The above description doesn't seem true after your second patch gets applied.
Cc: stable@vger.kernel.org Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Reviewed-by: Cornelia Huck cohuck@redhat.com Signed-off-by: Daniel Verkamp dverkamp@chromium.org
v1: https://lists.linuxfoundation.org/pipermail/virtualization/2019-December/04 4829.html
Changes from v1:
- Clarified "array" in commit message to "callbacks array"
drivers/virtio/virtio_balloon.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 93f995f6cf36..8e400ece9273 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -475,7 +475,9 @@ static int init_vqs(struct virtio_balloon *vb) names[VIRTIO_BALLOON_VQ_INFLATE] = "inflate"; callbacks[VIRTIO_BALLOON_VQ_DEFLATE] = balloon_ack; names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate";
- callbacks[VIRTIO_BALLOON_VQ_STATS] = NULL; names[VIRTIO_BALLOON_VQ_STATS] = NULL;
- callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
Could you remove other redundant NULL initialization well? https://lists.linuxfoundation.org/pipermail/virtualization/2019-December/044...
Best, Wei
On Sun, Jan 05, 2020 at 12:24:11PM +0000, Wang, Wei W wrote:
On Saturday, January 4, 2020 2:41 AM, Daniel Verkamp wrote:
Subject: [PATCH v2 1/2] virtio-balloon: initialize all vq callbacks
Ensure that elements of the callbacks array that correspond to unavailable features are set to NULL; previously, they would be left uninitialized.
Since the corresponding names array elements were explicitly set to NULL, the uninitialized callback pointers would not actually be dereferenced; however, the uninitialized callbacks elements would still be read in vp_find_vqs_msix() and used to calculate the number of MSI-X vectors required.
The above description doesn't seem true after your second patch gets applied.
Cc: stable@vger.kernel.org Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Reviewed-by: Cornelia Huck cohuck@redhat.com Signed-off-by: Daniel Verkamp dverkamp@chromium.org
v1: https://lists.linuxfoundation.org/pipermail/virtualization/2019-December/04 4829.html
Changes from v1:
- Clarified "array" in commit message to "callbacks array"
drivers/virtio/virtio_balloon.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 93f995f6cf36..8e400ece9273 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -475,7 +475,9 @@ static int init_vqs(struct virtio_balloon *vb) names[VIRTIO_BALLOON_VQ_INFLATE] = "inflate"; callbacks[VIRTIO_BALLOON_VQ_DEFLATE] = balloon_ack; names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate";
- callbacks[VIRTIO_BALLOON_VQ_STATS] = NULL; names[VIRTIO_BALLOON_VQ_STATS] = NULL;
- callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
Could you remove other redundant NULL initialization well? https://lists.linuxfoundation.org/pipermail/virtualization/2019-December/044...
Best, Wei
I queued as is, can be tweaked by a patch on top.
linux-stable-mirror@lists.linaro.org
-
Daniel Verkamp -
Michael S. Tsirkin -
Wang, Wei W