[03/26] ehci: Verify guest does not change the token of inflight qtd-s

Submitted by Hans de Goede on Dec. 14, 2012, 1:35 p.m.

Details

Message ID 1355492147-5023-4-git-send-email-hdegoede@redhat.com
State New
Headers show

Commit Message

Hans de Goede Dec. 14, 2012, 1:35 p.m.
This is not allowed, except for clearing active on cancellation, so don't
warn when the new token does not have its active bit set.

This unifies the cancellation path for modified qtd-s, and prepares
ehci_verify_qtd to be used ad an extra check inside
ehci_writeback_async_complete_packet().

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 hw/usb/hcd-ehci.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

Patch hide | download patch | download mbox

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index 0d31597..04301ce 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -461,6 +461,7 @@  static bool ehci_verify_qtd(EHCIPacket *p, EHCIqtd *qtd)
         (p->queue->async && !NLPTR_TBIT(p->qtd.next) &&
             (p->qtd.next != qtd->next)) ||
         (!NLPTR_TBIT(p->qtd.altnext) && (p->qtd.altnext != qtd->altnext)) ||
+        p->qtd.token != qtd->token ||
         p->qtd.bufptr[0] != qtd->bufptr[0]) {
         return false;
     } else {
@@ -1793,7 +1794,9 @@  static int ehci_state_fetchqtd(EHCIQueue *q)
     if (p != NULL) {
         if (!ehci_verify_qtd(p, &qtd)) {
             ehci_cancel_queue(q);
-            ehci_trace_guest_bug(q->ehci, "guest updated active QH or qTD");
+            if (qtd.token & QTD_TOKEN_ACTIVE) {
+                ehci_trace_guest_bug(q->ehci, "guest updated active qTD");
+            }
             p = NULL;
         } else {
             p->qtd = qtd;
@@ -1802,11 +1805,6 @@  static int ehci_state_fetchqtd(EHCIQueue *q)
     }
 
     if (!(qtd.token & QTD_TOKEN_ACTIVE)) {
-        if (p != NULL) {
-            /* transfer canceled by guest (clear active) */
-            ehci_cancel_queue(q);
-            p = NULL;
-        }
         ehci_set_state(q->ehci, q->async, EST_HORIZONTALQH);
     } else if (p != NULL) {
         switch (p->async) {