Re: [PATCH 3/3] KVM: Enable MSI-X for KVM assigned device

Marcelo Tosatti
2009-02-13T17:13:45Z

On Fri, Feb 13, 2009 at 01:29:42PM +0800, Sheng Yang wrote:
> The allocation only happen once, at the second time it would report error in
> current code. But allocate/deallocate is also acceptable for future.

Oops, it OK.

> > - interrupt context can read the table while kvm_vm_ioctl_set_msix_entry
> > is modifying it. So you either need to forbid more than one
> > kvm_vm_ioctl_set_msix_entry call in the lifetime of a guest (which
> > you can later allow when you support MSI table change), or handle
> > accesses from multiple contexes now. It seems forbidding is enough for
> > the moment from what you said.
>
> Yeah.
>
> But for the modifying the MSI-X table, the most critical problem is, current
> Linux didn't support it IIRC. So I have to disable MSI-X then enable it again
> with new table, and it would result in lost interrupt.
>
> So seems the most reasonable method is to modify pci_enable_msix() and related
> function's action to support this...

Alright, then just reply "[PATCH 1/3] KVM: Ioctls for init MSI-X entry"
with the minor comments reworked so Avi can apply.

Thanks.