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 <kra...@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> Message-id: 20200107083606.12393-1-kra...@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 0d3d96d05a00..fb05de4b0524 100644 --- a/hw/usb/hcd-xhci.c +++ b/hw/usb/hcd-xhci.c @@ -1861,6 +1861,13 @@ 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; @@ -1878,9 +1885,7 @@ 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; } @@ -1987,6 +1992,10 @@ 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); -- 2.18.1
