From: "Michael S. Tsirkin" <mst@redhat.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Anthony Liguori <aliguori@us.ibm.com>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
qemu-devel@nongnu.org, Alexander Graf <agraf@suse.de>,
qemu-trivial@nongnu.org,
Alex Williamson <alex.williamson@redhat.com>,
qemu-ppc@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>,
Paul Mackerras <paulus@samba.org>,
David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [Qemu-devel] [PATCH] RFC kvm irqfd: add directly mapped MSI IRQ support
Date: Mon, 24 Jun 2013 15:10:20 +0300 [thread overview]
Message-ID: <20130624121020.GA32114@redhat.com> (raw)
In-Reply-To: <1372023385.3944.108.camel@pasglop>
On Mon, Jun 24, 2013 at 07:36:25AM +1000, Benjamin Herrenschmidt wrote:
> On Sun, 2013-06-23 at 17:07 +0300, Michael S. Tsirkin wrote:
> > Yes I think that's fine really.
> >
> > Basically devices all speak MSIMessage as they should -
> > this is what the PCI spec says.
> > On all normal systems guests also speak MSIMessage so
> > the API which uses these makes sense for kvm.
> > Except, ppc architecture in its wisdom decided to hide this
> > in firmware. QEMU does not have firmware so the translation
> > has to be maintained in QEMU powerpc code.
>
> It is still not enough. There is nothing that says that an MSI
> address/message is unique. On pseries (among others I'm sure), this is a
> per-host-bridge concept since the MSIs are decoded by the PHB and turned
> into standard fabric interrupts there.
>
> So at least the bus needs to be passed as well.
>
> Cheers,
> Ben.
If passing bus (or dma context, etc)
turns out to actually be helpful, why not.
--
MST
next prev parent reply other threads:[~2013-06-24 12:09 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 14:08 [Qemu-devel] [PATCH] RFC kvm irqfd: add directly mapped MSI IRQ support Alexey Kardashevskiy
2013-06-20 15:38 ` Michael S. Tsirkin
2013-06-20 16:37 ` Anthony Liguori
2013-06-20 23:51 ` Alexey Kardashevskiy
2013-06-23 14:07 ` Michael S. Tsirkin
2013-06-23 15:02 ` Anthony Liguori
2013-06-23 21:39 ` [Qemu-devel] [Qemu-ppc] " Benjamin Herrenschmidt
2013-06-23 21:58 ` Anthony Liguori
2013-06-24 4:46 ` Alex Williamson
2013-06-24 12:24 ` Anthony Liguori
2013-06-24 12:39 ` Gleb Natapov
2013-06-23 21:36 ` [Qemu-devel] " Benjamin Herrenschmidt
2013-06-24 12:10 ` Michael S. Tsirkin [this message]
2013-06-20 16:51 ` Alex Williamson
2013-06-21 1:56 ` Alexey Kardashevskiy
2013-06-21 2:34 ` Alex Williamson
2013-06-21 2:49 ` Alexey Kardashevskiy
2013-06-21 4:46 ` Alex Williamson
2013-06-21 5:12 ` Benjamin Herrenschmidt
2013-06-21 6:03 ` Alex Williamson
2013-06-21 6:12 ` Benjamin Herrenschmidt
2013-06-21 6:40 ` Alexey Kardashevskiy
2013-06-23 15:06 ` Anthony Liguori
2013-06-24 4:44 ` Alex Williamson
2013-06-24 12:25 ` Anthony Liguori
2013-06-24 7:13 ` Gleb Natapov
2013-06-24 12:32 ` Anthony Liguori
2013-06-24 12:37 ` Alexander Graf
2013-06-24 13:06 ` Gleb Natapov
2013-06-24 13:34 ` Anthony Liguori
2013-06-24 13:41 ` Michael S. Tsirkin
2013-06-24 14:31 ` Anthony Liguori
2013-06-24 14:34 ` Alexander Graf
2013-06-24 15:17 ` Anthony Liguori
2013-06-24 16:48 ` Gleb Natapov
2013-06-24 16:35 ` Gleb Natapov
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