From 1406157e5944e023b07a644d5a8377db708134e8 Mon Sep 17 00:00:00 2001

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Date: Wed, 15 Jan 2020 12:07:42 +0100

Subject: [PATCH 4/7] xhci: recheck slot status

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RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>

Message-id: <20200115120742.19583-3-dgilbert@redhat.com>

Patchwork-id: 93353

O-Subject: [RHEL-8.2.0 qemu-kvm PATCH 2/2] xhci: recheck slot status

Bugzilla: 1752320

RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>

RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>

RH-Acked-by: Peter Xu <peterx@redhat.com>

From: Gerd Hoffmann <kraxel@redhat.com>

Factor out slot status check into a helper function.  Add an additional

check after completing transfers.  This is needed in case a guest

queues multiple transfers in a row and a device unplug happens while

qemu processes them.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1786413

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

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20200107083606.12393-1-kraxel@redhat.com

(cherry picked from commit 236846a019c4f7aa3111026fc9a1fe09684c8978)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 hw/usb/hcd-xhci.c | 15 ++++++++++++---

 1 file changed, 12 insertions(+), 3 deletions(-)

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

index 45fcce3..e63a603 100644

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

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

@@ -1853,6 +1853,13 @@ static void xhci_kick_ep(XHCIState *xhci, unsigned int slotid,

     xhci_kick_epctx(epctx, streamid);

 }

+static bool xhci_slot_ok(XHCIState *xhci, int slotid)

+{

+    return (xhci->slots[slotid - 1].uport &&

+            xhci->slots[slotid - 1].uport->dev &&

+            xhci->slots[slotid - 1].uport->dev->attached);

+}

+

 static void xhci_kick_epctx(XHCIEPContext *epctx, unsigned int streamid)

 {

     XHCIState *xhci = epctx->xhci;

@@ -1870,9 +1877,7 @@ static void xhci_kick_epctx(XHCIEPContext *epctx, unsigned int streamid)

     /* If the device has been detached, but the guest has not noticed this

        yet the 2 above checks will succeed, but we must NOT continue */

-    if (!xhci->slots[epctx->slotid - 1].uport ||

-        !xhci->slots[epctx->slotid - 1].uport->dev ||

-        !xhci->slots[epctx->slotid - 1].uport->dev->attached) {

+    if (!xhci_slot_ok(xhci, epctx->slotid)) {

         return;

     }

@@ -1968,6 +1973,10 @@ static void xhci_kick_epctx(XHCIEPContext *epctx, unsigned int streamid)

         } else {

             xhci_fire_transfer(xhci, xfer, epctx);

         }

+        if (!xhci_slot_ok(xhci, epctx->slotid)) {

+            /* surprise removal -> stop processing */

+            break;

+        }

         if (xfer->complete) {

             /* update ring dequeue ptr */

             xhci_set_ep_state(xhci, epctx, stctx, epctx->state);

-- 

1.8.3.1