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[Qemu-devel] [PATCH 12/17] uhci: Verify queue has not been changed by gu
From: |
Hans de Goede |
Subject: |
[Qemu-devel] [PATCH 12/17] uhci: Verify queue has not been changed by guest |
Date: |
Wed, 24 Oct 2012 18:31:15 +0200 |
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 <address@hidden>
---
hw/usb/hcd-uhci.c | 62 ++++++++++++++++++++++++++++++++++++++++---------------
trace-events | 2 +-
2 files changed, 46 insertions(+), 18 deletions(-)
diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c
index a8b74bd..0984bee 100644
--- a/hw/usb/hcd-uhci.c
+++ b/hw/usb/hcd-uhci.c
@@ -105,6 +105,7 @@ struct UHCIAsync {
};
struct UHCIQueue {
+ uint32_t qh_addr;
uint32_t token;
UHCIState *uhci;
USBEndpoint *ep;
@@ -170,20 +171,15 @@ static inline int32_t uhci_queue_token(UHCI_TD *td)
return td->token & 0x7ffff;
}
-static UHCIQueue *uhci_queue_get(UHCIState *s, UHCI_TD *td, USBEndpoint *ep)
+static UHCIQueue *uhci_queue_new(UHCIState *s, uint32_t qh_addr, UHCI_TD *td,
+ USBEndpoint *ep)
{
- uint32_t token = uhci_queue_token(td);
UHCIQueue *queue;
- QTAILQ_FOREACH(queue, &s->queues, next) {
- if (queue->token == token) {
- return queue;
- }
- }
-
queue = g_new0(UHCIQueue, 1);
queue->uhci = s;
- queue->token = token;
+ queue->qh_addr = qh_addr;
+ queue->token = uhci_queue_token(td);
queue->ep = ep;
QTAILQ_INIT(&queue->asyncs);
QTAILQ_INSERT_HEAD(&s->queues, queue, next);
@@ -191,7 +187,7 @@ static UHCIQueue *uhci_queue_get(UHCIState *s, UHCI_TD *td,
USBEndpoint *ep)
return queue;
}
-static void uhci_queue_free(UHCIQueue *queue)
+static void uhci_queue_free(UHCIQueue *queue, const char *reason)
{
UHCIState *s = queue->uhci;
UHCIAsync *async;
@@ -201,11 +197,35 @@ static void uhci_queue_free(UHCIQueue *queue)
uhci_async_cancel(async);
}
- trace_usb_uhci_queue_del(queue->token);
+ trace_usb_uhci_queue_del(queue->token, reason);
QTAILQ_REMOVE(&s->queues, queue, next);
g_free(queue);
}
+static UHCIQueue *uhci_queue_find(UHCIState *s, UHCI_TD *td)
+{
+ uint32_t token = uhci_queue_token(td);
+ UHCIQueue *queue;
+
+ QTAILQ_FOREACH(queue, &s->queues, next) {
+ if (queue->token == token) {
+ return queue;
+ }
+ }
+ return NULL;
+}
+
+static bool uhci_queue_verify(UHCIQueue *queue, uint32_t qh_addr, UHCI_TD *td,
+ uint32_t td_addr, bool queuing)
+{
+ UHCIAsync *first = QTAILQ_FIRST(&queue->asyncs);
+
+ return queue->qh_addr == qh_addr &&
+ queue->token == uhci_queue_token(td) &&
+ (queuing || !(td->ctrl & TD_CTRL_ACTIVE) || first == NULL ||
+ first->td_addr == td_addr);
+}
+
static UHCIAsync *uhci_async_alloc(UHCIQueue *queue, uint32_t td_addr)
{
UHCIAsync *async = g_new0(UHCIAsync, 1);
@@ -274,7 +294,7 @@ static void uhci_async_validate_end(UHCIState *s)
QTAILQ_FOREACH_SAFE(queue, &s->queues, next, n) {
if (!queue->valid) {
- uhci_queue_free(queue);
+ uhci_queue_free(queue, "validate-end");
}
}
}
@@ -295,7 +315,7 @@ static void uhci_async_cancel_all(UHCIState *s)
UHCIQueue *queue, *nq;
QTAILQ_FOREACH_SAFE(queue, &s->queues, next, nq) {
- uhci_queue_free(queue);
+ uhci_queue_free(queue, "cancel-all");
}
}
@@ -782,7 +802,7 @@ out:
return err;
}
-static int uhci_handle_td(UHCIState *s, UHCIQueue *q,
+static int uhci_handle_td(UHCIState *s, UHCIQueue *q, uint32_t qh_addr,
UHCI_TD *td, uint32_t td_addr, uint32_t *int_mask)
{
UHCIAsync *async;
@@ -791,6 +811,14 @@ static int uhci_handle_td(UHCIState *s, UHCIQueue *q,
bool queuing = (q != NULL);
uint8_t pid = td->token & 0xff;
+ if (q == NULL) {
+ q = uhci_queue_find(s, td);
+ if (q && !uhci_queue_verify(q, qh_addr, td, td_addr, queuing)) {
+ uhci_queue_free(q, "guest re-used qh");
+ q = NULL;
+ }
+ }
+
/* Is active ? */
if (!(td->ctrl & TD_CTRL_ACTIVE)) {
/*
@@ -825,7 +853,7 @@ static int uhci_handle_td(UHCIState *s, UHCIQueue *q,
if (q == NULL) {
USBDevice *dev = uhci_find_device(s, (td->token >> 8) & 0x7f);
USBEndpoint *ep = usb_ep_get(dev, pid, (td->token >> 15) & 0xf);
- q = uhci_queue_get(s, td, ep);
+ q = uhci_queue_new(s, qh_addr, td, ep);
}
async = uhci_async_alloc(q, td_addr);
@@ -954,7 +982,7 @@ static void uhci_queue_fill(UHCIQueue *q, UHCI_TD *td)
break;
}
trace_usb_uhci_td_queue(plink & ~0xf, ptd.ctrl, ptd.token);
- ret = uhci_handle_td(q->uhci, q, &ptd, plink, &int_mask);
+ ret = uhci_handle_td(q->uhci, q, q->qh_addr, &ptd, plink, &int_mask);
if (ret == TD_RESULT_ASYNC_CONT) {
break;
}
@@ -1035,7 +1063,7 @@ static void uhci_process_frame(UHCIState *s)
trace_usb_uhci_td_load(curr_qh & ~0xf, link & ~0xf, td.ctrl, td.token);
old_td_ctrl = td.ctrl;
- ret = uhci_handle_td(s, NULL, &td, link, &int_mask);
+ ret = uhci_handle_td(s, NULL, curr_qh, &td, link, &int_mask);
if (old_td_ctrl != td.ctrl) {
/* update the status bits of the TD */
val = cpu_to_le32(td.ctrl);
diff --git a/trace-events b/trace-events
index f5b5097..6647fc4 100644
--- a/trace-events
+++ b/trace-events
@@ -283,7 +283,7 @@ 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"
--
1.7.12.1
- [Qemu-devel] [PATCH 02/17] uhci: No need to handle async completion of isoc packets, (continued)
- [Qemu-devel] [PATCH 02/17] uhci: No need to handle async completion of isoc packets, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 07/17] uhci: Rename UHCIAsync->td to UHCIAsync->td_addr, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 06/17] uhci: Move emptying of the queue's asyncs' queue to uhci_queue_free, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 04/17] uhci: Don't retry on error, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 09/17] uhci: Make uhci_fill_queue() actually operate on an UHCIQueue, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 05/17] uhci: Drop unnecessary forward declaration of some static functions, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 08/17] uhci: Add uhci_read_td() helper function, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 03/17] uhci: cleanup: Add an unlink call to uhci_async_cancel(), Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 11/17] uhci: Immediately free queues on device disconnect, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 13/17] uhci: Detect guest td re-use, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 12/17] uhci: Verify queue has not been changed by guest,
Hans de Goede <=
- [Qemu-devel] [PATCH 10/17] uhci: Store ep in UHCIQueue, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 14/17] uhci: When the guest marks a pending td non-active, cancel the queue, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 17/17] uhci: Use only one queue for ctrl endpoints, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 16/17] uhci: Retry to fill the queue while waiting for td completion, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 15/17] uhci: Always mark a queue valid when we encounter it, Hans de Goede, 2012/10/24
- Re: [Qemu-devel] uhci: Cleanups, fixes and improvements, Gerd Hoffmann, 2012/10/25