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Re: [Qemu-devel] [PATCH] xhci: flush dequeue pointer to endpoint context
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH] xhci: flush dequeue pointer to endpoint context |
Date: |
Fri, 31 Mar 2017 11:39:11 +0100 |
User-agent: |
Mutt/1.8.0 (2017-02-23) |
* Gerd Hoffmann (address@hidden) wrote:
> When done processing a endpoint ring we must update the dequeue pointer
> in the endpoint context in guest memory. This is needed to make sure
> the guest has a correct view of things and also to make live migration
> work properly, because xhci post_load restores alot of the state from
> xhci data structures in guest memory.
>
> Add xhci_set_ep_state() call to do that.
>
> The recursive calls stopped by commit
> ddb603ab6c981c1d67cb42266fc700c33e5b2d8f had the (unintentional) side
> effect to hiding this bug. xhci_set_ep_state() was called before
> processing, to set the state to running, which updated the dequeue
> pointer too.
>
> Reported-by: Dr. David Alan Gilbert <address@hidden>
> Signed-off-by: Gerd Hoffmann <address@hidden>
Tested-by: Dr. David Alan Gilbert <address@hidden>
Thanks, that passes the basic test reported in the bz; boot the VM,
lsblk, migrate, fdisk -l
Dave
> ---
> hw/usb/hcd-xhci.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
> index 8958f95..a6929e5 100644
> --- a/hw/usb/hcd-xhci.c
> +++ b/hw/usb/hcd-xhci.c
> @@ -2063,7 +2063,7 @@ static void xhci_kick_ep(XHCIState *xhci, unsigned int
> slotid,
> static void xhci_kick_epctx(XHCIEPContext *epctx, unsigned int streamid)
> {
> XHCIState *xhci = epctx->xhci;
> - XHCIStreamContext *stctx;
> + XHCIStreamContext *stctx = NULL;
> XHCITransfer *xfer;
> XHCIRing *ring;
> USBEndpoint *ep = NULL;
> @@ -2192,6 +2192,8 @@ static void xhci_kick_epctx(XHCIEPContext *epctx,
> unsigned int streamid)
> break;
> }
> }
> + /* update ring dequeue ptr */
> + xhci_set_ep_state(xhci, epctx, stctx, epctx->state);
> epctx->kick_active--;
>
> ep = xhci_epid_to_usbep(epctx);
> --
> 2.9.3
>
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK