| commit | 82cffa2eb255731b8402e206d0434cc884d99e54 | |
| author | Cédric Le Goater <clg@kaod.org> | |
| Mon, 30 Jul 2018 14:11:32 +0000 (30 16:11 +0200) | ||
| committer | David Gibson <david@gibson.dropbear.id.au> | |
| Tue, 21 Aug 2018 04:28:45 +0000 (21 14:28 +1000) | ||
| tree | 763ef42808493580b1716ad8968162d43c6b743a | treesnapshot (tar.gz zip) |
| parent | d45360d93d71578919ae8065a142beb941a900fd | commitdiff |
spapr: introduce a fixed IRQ number space
This proposal introduces a new IRQ number space layout using static
numbers for all devices, depending on a device index, and a bitmap
allocator for the MSI IRQ numbers which are negotiated by the guest at
runtime.
As the VIO device model does not have a device index but a "reg"
property, we introduce a formula to compute an IRQ number from a "reg"
value. It should minimize most of the collisions.
The previous layout is kept in pre-3.1 machines raising the
'legacy_irq_allocation' machine class flag.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This proposal introduces a new IRQ number space layout using static
numbers for all devices, depending on a device index, and a bitmap
allocator for the MSI IRQ numbers which are negotiated by the guest at
runtime.
As the VIO device model does not have a device index but a "reg"
property, we introduce a formula to compute an IRQ number from a "reg"
value. It should minimize most of the collisions.
The previous layout is kept in pre-3.1 machines raising the
'legacy_irq_allocation' machine class flag.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>