This is a note to let you know that I've just added the patch titled
genirq/msi: Shutdown managed interrupts with unsatifiable affinities
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
genirq-msi-shutdown-managed-interrupts-with-unsatifiable-affinities.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Nov 30 06:09:32 PM CET 2022
From: Luiz Capitulino <luizcap@xxxxxxxxxx>
Date: Mon, 28 Nov 2022 17:08:32 +0000
Subject: genirq/msi: Shutdown managed interrupts with unsatifiable affinities
To: <stable@xxxxxxxxxxxxxxx>, <maz@xxxxxxxxxx>
Cc: <tglx@xxxxxxxxxxxxx>, <lcapitulino@xxxxxxxxx>, John Garry <john.garry@xxxxxxxxxx>, David Decotigny <ddecotig@xxxxxxxxxx>, "Luiz Capitulino" <luizcap@xxxxxxxxxx>
Message-ID: <987f78b332076edcf0b05d169bcd2694edee7c05.1669655291.git.luizcap@xxxxxxxxxx>
From: Luiz Capitulino <luizcap@xxxxxxxxxx>
From: Marc Zyngier <maz@xxxxxxxxxx>
commit d802057c7c553ad426520a053da9f9fe08e2c35a upstream.
[ This commit is almost a rewrite because it conflicts with Thomas
Gleixner's refactoring of this code in v5.17-rc1. I wasn't sure if
I should drop all the s-o-bs (including Mark's), but decided
to keep as the original commit ]
When booting with maxcpus=<small number>, interrupt controllers
such as the GICv3 ITS may not be able to satisfy the affinity of
some managed interrupts, as some of the HW resources are simply
not available.
The same thing happens when loading a driver using managed interrupts
while CPUs are offline.
In order to deal with this, do not try to activate such interrupt
if there is no online CPU capable of handling it. Instead, place
it in shutdown state. Once a capable CPU shows up, it will be
activated.
Reported-by: John Garry <john.garry@xxxxxxxxxx>
Reported-by: David Decotigny <ddecotig@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: John Garry <john.garry@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220405185040.206297-2-maz@xxxxxxxxxx
Signed-off-by: Luiz Capitulino <luizcap@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/irq/msi.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -596,6 +596,13 @@ int __msi_domain_alloc_irqs(struct irq_d
irqd_clr_can_reserve(irq_data);
if (domain->flags & IRQ_DOMAIN_MSI_NOMASK_QUIRK)
irqd_set_msi_nomask_quirk(irq_data);
+ if ((info->flags & MSI_FLAG_ACTIVATE_EARLY) &&
+ irqd_affinity_is_managed(irq_data) &&
+ !cpumask_intersects(irq_data_get_affinity_mask(irq_data),
+ cpu_online_mask)) {
+ irqd_set_managed_shutdown(irq_data);
+ continue;
+ }
}
ret = irq_domain_activate_irq(irq_data, can_reserve);
if (ret)
Patches currently in stable-queue which might be from luizcap@xxxxxxxxxx are
queue-5.15/genirq-take-the-proposed-affinity-at-face-value-if-force-true.patch
queue-5.15/genirq-always-limit-the-affinity-to-online-cpus.patch
queue-5.15/genirq-msi-shutdown-managed-interrupts-with-unsatifiable-affinities.patch
queue-5.15/irqchip-gic-v3-always-trust-the-managed-affinity-provided-by-the-core-code.patch
