From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 14 Dec 2012 13:35:24 +0000 (+0100)
Subject: ehci: Verify guest does not change the token of inflight qtd-s
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d066c57b1c97a1967c949aba643bba35329b32ee;p=qemu.git

ehci: Verify guest does not change the token of inflight qtd-s

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>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index 0d315971a9..04301ce173 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) {