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Differential D17991

Axe MINIMUM_MSI_INT.
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Authored by jhb on Nov 14 2018, 8:04 PM.
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Reviewers
kib
markj
royger
Commits
rS340488: Axe MINIMUM_MSI_INT.
Summary

Just allow MSI interrupts to always start at the end of the I/O APIC
pins. Since existing machines already have more than 255 I/O APIC
pins, IRQ 255 is no longer reliably invalid, so just remove the
minimum starting value for MSI.

Test Plan
  • boot an amd64 VM under bhyve
  • I have not tested Xen.

Diff Detail

Repository
rS FreeBSD src repository - subversion
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Event Timeline

jhb created this revision.Nov 14 2018, 8:04 PM
Harbormaster completed remote builds in B20810: Diff 50426.Nov 14 2018, 8:04 PM
jhb marked an inline comment as done.Nov 14 2018, 8:05 PM

It is perhaps debatable if we want this change since it will change the IRQ values users see (and users might be used to >= 256 meaning MSI), and I probably won't MFC it if we do decide we want it in HEAD for those reasons.

sys/x86/xen/pvcpu_enum.c
202 ↗(On Diff #50426)

I believe this matches the intent of the comment.

jhb updated this revision to Diff 50428.Nov 14 2018, 8:32 PM

Rebase.

Harbormaster completed remote builds in B20812: Diff 50428.Nov 14 2018, 8:32 PM
kib added a comment.Nov 14 2018, 8:59 PM

May be export the first_msi_irq as ro mib ?

jhb updated this revision to Diff 50493.Nov 16 2018, 5:58 PM
  • Add a read-only sysctl for first_msi_irq.
Harbormaster completed remote builds in B20840: Diff 50493.Nov 16 2018, 5:58 PM
markj accepted this revision.Nov 16 2018, 7:39 PM
This revision is now accepted and ready to land.Nov 16 2018, 7:39 PM
kib accepted this revision.Nov 16 2018, 8:06 PM
Closed by commit rS340488: Axe MINIMUM_MSI_INT. (authored by jhb). · Explain WhyNov 16 2018, 11:40 PM
This revision was automatically updated to reflect the committed changes.
Herald added a subscriber: imp. · View Herald TranscriptNov 16 2018, 11:40 PM

Revision Contents
Changeset List

PathSize
head/
sys/
x86/
include/
12 lines
x86/
4 lines
xen/
2 lines
2 lines

Diff 50509

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head/sys/x86/include/intr_machdep.h

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head/sys/x86/x86/msi.c

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head/sys/x86/xen/pvcpu_enum.c

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head/sys/x86/xen/xen_msi.c

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