From: "Michael S. Tsirkin" <mst@redhat.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: Avi Kivity <avi@redhat.com>, Sheng Yang <sheng@linux.intel.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
kvm@vger.kernel.org
Subject: Re: [PATCH 0/8][v2] MSI-X mask emulation support for assigned device
Date: Thu, 21 Oct 2010 00:06:52 +0200 [thread overview]
Message-ID: <20101020220652.GC27220@redhat.com> (raw)
In-Reply-To: <1287605581.3007.59.camel@x201>
On Wed, Oct 20, 2010 at 02:13:01PM -0600, Alex Williamson wrote:
> On Wed, 2010-10-20 at 17:13 +0200, Michael S. Tsirkin wrote:
> > On Wed, Oct 20, 2010 at 09:07:12AM -0600, Alex Williamson wrote:
> > > On Wed, 2010-10-20 at 16:46 +0200, Michael S. Tsirkin wrote:
> > > > On Wed, Oct 20, 2010 at 08:47:14AM -0600, Alex Williamson wrote:
> > > > > It would probably make sense to request a mask/unmask ioctl in VFIO for
> > > > > MSI-X, then perhaps the pending bits would only support read/write (no
> > > > > mmap), so we could avoid an ioctl there.
> > > >
> > > > Why not mask/unmask with a write?
> > >
> > > That would be possible too, only trouble is then we have QEMU
> > > intercepting and interpreting the write as well as VFIO intercepting and
> > > interpreting the write.
> > > If VFIO is only masking off the mask bit,
> > > that'd be pretty trivial though.
> >
> > I just mean write() instead of an ioctl()
>
> Hmm, looking back through my vfio driver, I actually have some code that
> passes guest writes of the vector control field down to vfio. With
> interrupt remapping support, vfio should pass these to the device
> masking the interrupt at the source so we don't even need pending bit
> emulation.
No, that would conflict with kernel using mask bits.
If we do this this direct access is very wrong, we must use kernel APIs for this.
> Then we just need to make sure we only filter out the vector
> table for read/write of the page it lives on so we can support the PBA
> being on the same page.
>
> Alex
>
>
next prev parent reply other threads:[~2010-10-20 22:13 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-20 8:26 [PATCH 0/8][v2] MSI-X mask emulation support for assigned device Sheng Yang
2010-10-20 8:26 ` [PATCH 1/8] PCI: MSI: Move MSI-X entry definition to pci_regs.h Sheng Yang
2010-10-20 11:07 ` Matthew Wilcox
2010-10-20 8:26 ` [PATCH 2/8] irq: Export irq_to_desc() to modules Sheng Yang
2010-10-20 8:26 ` [PATCH 3/8] KVM: x86: Enable ENABLE_CAP capability for x86 Sheng Yang
2010-10-20 8:26 ` [PATCH 4/8] KVM: Move struct kvm_io_device to kvm_host.h Sheng Yang
2010-10-20 8:26 ` [PATCH 5/8] KVM: Add kvm_get_irq_routing_entry() func Sheng Yang
2010-10-20 8:53 ` Avi Kivity
2010-10-20 8:58 ` Sheng Yang
2010-10-20 9:13 ` Sheng Yang
2010-10-20 9:17 ` Sheng Yang
2010-10-20 9:32 ` Avi Kivity
2010-10-20 8:26 ` [PATCH 6/8] KVM: assigned dev: Preparation for mask support in userspace Sheng Yang
2010-10-20 9:30 ` Avi Kivity
2010-10-22 14:53 ` Marcelo Tosatti
2010-10-24 12:19 ` Sheng Yang
2010-10-24 12:23 ` Michael S. Tsirkin
2010-10-28 8:21 ` Sheng Yang
2010-10-20 8:26 ` [PATCH 7/8] KVM: assigned dev: Introduce io_device for MSI-X MMIO accessing Sheng Yang
2010-10-20 9:46 ` Avi Kivity
2010-10-20 10:33 ` Michael S. Tsirkin
2010-10-21 6:46 ` Sheng Yang
2010-10-21 9:27 ` Avi Kivity
2010-10-21 9:24 ` Michael S. Tsirkin
2010-10-21 9:47 ` Avi Kivity
2010-10-21 10:51 ` Michael S. Tsirkin
2010-10-20 22:35 ` Michael S. Tsirkin
2010-10-21 7:44 ` Sheng Yang
2010-10-20 8:26 ` [PATCH 8/8] KVM: Emulation MSI-X mask bits for assigned devices Sheng Yang
2010-10-20 9:49 ` Avi Kivity
2010-10-20 22:24 ` Michael S. Tsirkin
2010-10-21 8:30 ` Sheng Yang
2010-10-21 8:39 ` Michael S. Tsirkin
2010-10-22 4:42 ` Sheng Yang
2010-10-22 10:17 ` Michael S. Tsirkin
2010-10-22 13:30 ` Sheng Yang
2010-10-22 14:32 ` Michael S. Tsirkin
2010-10-20 9:51 ` [PATCH 0/8][v2] MSI-X mask emulation support for assigned device Avi Kivity
2010-10-20 10:44 ` Michael S. Tsirkin
2010-10-20 10:59 ` Avi Kivity
2010-10-20 13:43 ` Michael S. Tsirkin
2010-10-20 14:58 ` Alex Williamson
2010-10-20 14:58 ` Michael S. Tsirkin
2010-10-20 15:12 ` Alex Williamson
2010-10-20 15:17 ` Avi Kivity
2010-10-20 15:22 ` Alex Williamson
2010-10-20 15:26 ` Avi Kivity
2010-10-20 15:38 ` Alex Williamson
2010-10-20 14:47 ` Alex Williamson
2010-10-20 14:46 ` Michael S. Tsirkin
2010-10-20 15:07 ` Alex Williamson
2010-10-20 15:13 ` Michael S. Tsirkin
2010-10-20 20:13 ` Alex Williamson
2010-10-20 22:06 ` Michael S. Tsirkin [this message]
2010-10-20 15:23 ` Avi Kivity
2010-10-20 15:38 ` Alex Williamson
2010-10-20 15:54 ` Avi Kivity
2010-10-20 15:59 ` Michael S. Tsirkin
2010-10-20 16:13 ` Avi Kivity
2010-10-20 17:11 ` Michael S. Tsirkin
2010-10-20 18:31 ` Alex Williamson
2010-10-21 7:41 ` Sheng Yang
2010-10-20 19:02 ` Marcelo Tosatti
2010-10-21 7:10 ` Sheng Yang
2010-10-21 8:21 ` Michael S. Tsirkin
2010-10-20 22:20 ` Michael S. Tsirkin
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