> -----Original Message----- > From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx] > Sent: Monday, May 30, 2016 7:18 AM > To: linux-pci@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; Bjorn > Helgaas <bhelgaas@xxxxxxxxxx>; Haiyang Zhang > <haiyangz@xxxxxxxxxxxxx>; KY Srinivasan <kys@xxxxxxxxxxxxx>; Jake > Oshins <jakeo@xxxxxxxxxxxxx> > 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 <vkuznets@xxxxxxxxxx> Acked-by: Jake Oshins <jakeo@xxxxxxxxxxxxx> > --- > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
