From mboxrd@z Thu Jan  1 00:00:00 1970
From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Subject: Re: passthroughed msix device
Date: Wed, 27 Feb 2013 13:49:58 +0800
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To: Jan Beulich <JBeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>, xen-devel <xen-devel@lists.xen.org>, Joe Jin <joe.jin@oracle.com>, stefano.stabellini@eu.citrix.com
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On 2013-02-26 18:08, Jan Beulich wrote:
>>>> On 26.02.13 at 09:56, DuanZhenzhong <zhenzhong.duan@oracle.com> wrote:
>> pci_msix_writel: Can't update entry 0 since MSI-X is already enabled
>> (fee00000 -> fee02000)
>> pci_msix_writel: Can't update entry 0 since MSI-X is already enabled
>> (00004059 -> 00004071)
> If you look at the code issuing this message, the situation is
> pretty clear (and I think it as described already in the past,
> albeit I have no link at hand): qemu lacks proper emulation of
> the mask bit. pci_msix_write() looks at the physical one, yet
> when the guest sets the virtual mask bit, nothing is being
> done at all to make the hypervisor also mask the physical
> entry:
>
>      if (offset == PCI_MSIX_ENTRY_VECTOR_CTRL) {
>          if (msix->enabled && !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
>              xen_pt_msix_update_one(s, entry_nr);
>          }
>      }
>
> There's probably quite a bit of code to be written to make this
> work.
Is there plan of fixing it?

thanks
zduan