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[Qemu-devel] [PATCH v2 for-1.6 0/2] virtio-mmio: fixes to QueueNum, Queu
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH v2 for-1.6 0/2] virtio-mmio: fixes to QueueNum, QueueNumMax |
Date: |
Fri, 26 Jul 2013 16:41:26 +0100 |
These patches fix a couple of bugs in virtio-mmio's
handling of the registers that deal with the queue size:
* as mst points out, letting the guest flip a queue between
"exists" and "doesn't exist" is a bad idea
* QueueNumMax wasn't reading the correct value for nonexistent
queues
This doesn't include any change to the behaviour of queuesize
on reset (discussed in other thread); the current behaviour is
not a problem for well-behaved guests, and safe in the face
of badly-behaved guests, and currently improving the reset
behaviour is blocked by an unrelated bug.
v1->v2: changes as per mst review:
* avoid explicit "== 0" comparisons
* avoid unnecessary parens round comparison ops
* do the "don't flip between existent and nonexistent" check
with "!!num != !!oldnum" (and add a comment noting why we're
doing this check)
Peter Maydell (2):
hw/virtio/virtio: Don't allow guests to add/remove queues
hw/virtio/virtio-mmio: Make QueueNumMax read 0 for unavailable queues
hw/virtio/virtio-mmio.c | 3 +++
hw/virtio/virtio.c | 12 +++++++++---
2 files changed, 12 insertions(+), 3 deletions(-)
--
1.7.9.5
- [Qemu-devel] [PATCH v2 for-1.6 0/2] virtio-mmio: fixes to QueueNum, QueueNumMax,
Peter Maydell <=