uhci: Verify queue has not been changed by guest

According to the spec a guest can unlink a qh, and then as soon as frindex
has changed by 1 since the unlink, assume it is idle and re-use it. However
for various reasons, we cannot simply consider a qh as unlinked if we've not
seen it for 1 frame. This means that it is possible for a guest to re-use /
restart the queue while we still see its old state. This patch adds a safety
check for this, and "early" retires queues when they were changed by the guest.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Hans de Goede 2012-10-24 18:31:15 +02:00 committed by Gerd Hoffmann
parent 5ad23e873c
commit 66a08cbe6a
2 changed files with 46 additions and 18 deletions

View file

@ -287,7 +287,7 @@ usb_uhci_mmio_writew(uint32_t addr, uint32_t val) "addr 0x%04x, val 0x%04x"
usb_uhci_mmio_readl(uint32_t addr, uint32_t val) "addr 0x%04x, ret 0x%08x"
usb_uhci_mmio_writel(uint32_t addr, uint32_t val) "addr 0x%04x, val 0x%08x"
usb_uhci_queue_add(uint32_t token) "token 0x%x"
usb_uhci_queue_del(uint32_t token) "token 0x%x"
usb_uhci_queue_del(uint32_t token, const char *reason) "token 0x%x: %s"
usb_uhci_packet_add(uint32_t token, uint32_t addr) "token 0x%x, td 0x%x"
usb_uhci_packet_link_async(uint32_t token, uint32_t addr) "token 0x%x, td 0x%x"
usb_uhci_packet_unlink_async(uint32_t token, uint32_t addr) "token 0x%x, td 0x%x"