From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@quanstro.net>
Date: Fri,  9 May 2014 16:44:51 -0400
To: 9fans@9fans.net
Message-ID: <41ab952ad099c8e959649088b919a620@ladd.quanstro.net>
In-Reply-To: <CAP6exYL5KwdwKGM-KkFboHXpTt+Xv7o7WnHLm08OPGY1QX-xmg@mail.gmail.com>
References: <CAP6exYL5KwdwKGM-KkFboHXpTt+Xv7o7WnHLm08OPGY1QX-xmg@mail.gmail.com>
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Subject: Re: [9fans] what arch
Topicbox-Message-UUID: e5130878-ead8-11e9-9d60-3106f5b1d025

> Also, from the Akaros side, we've extended the Plan 9 MSI code to
> support MSI-X and tested it on real hardware; works fine. This allowed
> us to stop worrying about ACPI; you don't need it if you do MSI-X.
> Relief! And MSI-X is in some ways easier than MSI.

i don't see how this could be the case for some pretty common hardware.
for example, i have yet to see a usb controller that will do either
msi or msi-x.

for example, on this machine (random intel)

	; pci |grep usb
	0.26.0:	usb  0c.03.20 8086/1c2d  11 0:fbc23000 1024
	0.29.0:	usb  0c.03.20 8086/1c26   5 0:fbc22000 1024
	; pci -vc 0.26.0 0.29.0
	0.26.0: pwrmgmt/01 dbgprt/0a advfeat/13
	0.29.0: pwrmgmt/01 dbgprt/0a advfeat/13

nope.  it's i/o apic interrupts for me!  unless there's some magic way
to convert i/o apic into msi-x that i don't know about.  hoping this
is the case....

- erik