Patchwork [06/10] ehci: Verify guest does not change the token of inflight qtd-s

login
register
mail settings
Submitter Hans de Goede
Date Nov. 14, 2012, 4:21 p.m.
Message ID <1352910105-10272-7-git-send-email-hdegoede@redhat.com>
Download mbox | patch
Permalink /patch/198961/
State New
Headers show

Comments

Hans de Goede - Nov. 14, 2012, 4:21 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

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index a694346..e565d6a 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -457,6 +457,7 @@  static bool ehci_verify_qtd(EHCIPacket *p, EHCIqtd *qtd)
     if (p->qtdaddr != p->queue->qtdaddr ||
         (!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 {
@@ -1748,7 +1749,9 @@  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;
@@ -1757,11 +1760,6 @@  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) {