From 82b29b635d26ad0f5e14fabdf0956e9b8e7dbbfb Mon Sep 17 00:00:00 2001

From: Gerd Hoffmann <kraxel@redhat.com>

Date: Fri, 31 Aug 2012 10:44:21 +0200

Subject: [PATCH] ehci: trace guest bugs

make qemu_queue_{cancel,reset} return the number of packets released,

so the caller can figure whenever there have been active packets even

though there shouldn't have been any.  Add tracepoint to log this.

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

(cherry picked from commit 5c514681abbb3ae2f61f517c1aa3197f2f3ca93c)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

---

 hw/usb/hcd-ehci.c | 26 ++++++++++++++++++++------

 trace-events      |  1 +

 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c

index 23221d0..4564615 100644

--- a/hw/usb/hcd-ehci.c

+++ b/hw/usb/hcd-ehci.c

@@ -716,6 +716,12 @@ static void ehci_trace_sitd(EHCIState *s, target_phys_addr_t addr,

                         (bool)(sitd->results & SITD_RESULTS_ACTIVE));

 }

+static void ehci_trace_guest_bug(EHCIState *s, const char *message)

+{

+    trace_usb_ehci_guest_bug(message);

+    fprintf(stderr, "ehci warning: %s\n", message);

+}

+

 static inline bool ehci_enabled(EHCIState *s)

 {

     return s->usbcmd & USBCMD_RUNSTOP;

@@ -785,27 +791,33 @@ static EHCIQueue *ehci_alloc_queue(EHCIState *ehci, uint32_t addr, int async)

     return q;

 }

-static void ehci_cancel_queue(EHCIQueue *q)

+static int ehci_cancel_queue(EHCIQueue *q)

 {

     EHCIPacket *p;

+    int packets = 0;

     p = QTAILQ_FIRST(&q->packets);

     if (p == NULL) {

-        return;

+        return 0;

     }

     trace_usb_ehci_queue_action(q, "cancel");

     do {

         ehci_free_packet(p);

+        packets++;

     } while ((p = QTAILQ_FIRST(&q->packets)) != NULL);

+    return packets;

 }

-static void ehci_reset_queue(EHCIQueue *q)

+static int ehci_reset_queue(EHCIQueue *q)

 {

+    int packets;

+

     trace_usb_ehci_queue_action(q, "reset");

-    ehci_cancel_queue(q);

+    packets = ehci_cancel_queue(q);

     q->dev = NULL;

     q->qtdaddr = 0;

+    return packets;

 }

 static void ehci_free_queue(EHCIQueue *q)

@@ -1817,7 +1829,9 @@ static EHCIQueue *ehci_state_fetchqh(EHCIState *ehci, int async)

         (memcmp(&qh.current_qtd, &q->qh.current_qtd,

                                  9 * sizeof(uint32_t)) != 0) ||

         (q->dev != NULL && q->dev->addr != devaddr)) {

-        ehci_reset_queue(q);

+        if (ehci_reset_queue(q) > 0) {

+            ehci_trace_guest_bug(ehci, "guest updated active QH");

+        }

         p = NULL;

     }

     q->qh = qh;

@@ -1979,8 +1993,8 @@ static int ehci_state_fetchqtd(EHCIQueue *q)

             (!NLPTR_TBIT(p->qtd.next) && (p->qtd.next != qtd.next)) ||

             (!NLPTR_TBIT(p->qtd.altnext) && (p->qtd.altnext != qtd.altnext)) ||

             p->qtd.bufptr[0] != qtd.bufptr[0]) {

-            /* guest bug: guest updated active QH or qTD underneath us */

             ehci_cancel_queue(q);

+            ehci_trace_guest_bug(q->ehci, "guest updated active QH or qTD");

             p = NULL;

         } else {

             p->qtd = qtd;

diff --git a/trace-events b/trace-events

index 8fcbc50..5112a47 100644

--- a/trace-events

+++ b/trace-events

@@ -263,6 +263,7 @@ usb_ehci_data(int rw, uint32_t cpage, uint32_t offset, uint32_t addr, uint32_t l

 usb_ehci_queue_action(void *q, const char *action) "q %p: %s"

 usb_ehci_packet_action(void *q, void *p, const char *action) "q %p p %p: %s"

 usb_ehci_irq(uint32_t level, uint32_t frindex, uint32_t sts, uint32_t mask) "level %d, frindex 0x%04x, sts 0x%x, mask 0x%x"

+usb_ehci_guest_bug(const char *reason) "%s"

 # hw/usb/hcd-uhci.c

 usb_uhci_reset(void) "=== RESET ==="

-- 

1.7.12.1