> -----Original Message-----
> From: Vitaly Kuznetsov [mailto:vkuzn...@redhat.com]
> Sent: Monday, May 30, 2016 7:18 AM
> To: linux-...@vger.kernel.org
> Cc: linux-ker...@vger.kernel.org; de...@linuxdriverproject.org; Bjorn
> Helgaas <bhelg...@google.com>; Haiyang Zhang
> <haiya...@microsoft.com>; KY Srinivasan <k...@microsoft.com>; Jake
> Oshins <ja...@microsoft.com>
> Subject: [PATCH 2/2] PCI: hv: handle all pending messages in
> hv_pci_onchannelcallback()
>
> When we have an interrupt from host we have a bit set in event page
> indicating there are messages for the particular channel. We need to read
> them all as we won't get signaled for what was on the queue before we
> cleared the bit in vmbus_on_event(). This applies to all Hyper-V drivers
> and the pass-through driver should do the same.
> I did non meet any bugs, the issue was found by code inspection. We don't
> have many events going through hv_pci_onchannelcallback(), this explains
> why nobody reported the issue before.
>
> While on it, fix handling non-zero vmbus_recvpacket_raw() return values by
> dropping out. If the return value is not zero it is wrong to inspect
> buffer or bytes_recvd as these may contain invalid data.
>
> Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
Acked-by: Jake Oshins <ja...@microsoft.com>
> ---
> drivers/pci/host/pci-hyperv.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index a68ec49..7de341d 100644
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -1657,12 +1657,16 @@ static void hv_pci_onchannelcallback(void
> *context)
> continue;
> }
>
> + /* Zero length indicates there are no more packets. */
> + if (ret || !bytes_recvd)
> + break;
> +
> /*
> * All incoming packets must be at least as large as a
> * response.
> */
> if (bytes_recvd <= sizeof(struct pci_response))
> - break;
> + continue;
> desc = (struct vmpacket_descriptor *)buffer;
>
> switch (desc->type) {
> @@ -1724,7 +1728,6 @@ static void hv_pci_onchannelcallback(void
> *context)
> desc->type, req_id, bytes_recvd);
> break;
> }
> - break;
> }
>
> kfree(buffer);
> --
> 2.5.5
This is good, too.
Thanks,
Jake Oshins
_______________________________________________
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
