From: Marc Zyngier maz@kernel.org
mainline inclusion from mainline-v5.19-rc1 commit d802057c7c553ad426520a053da9f9fe08e2c35a category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5F4TK CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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@huawei.com Reported-by: David Decotigny ddecotig@google.com Signed-off-by: Marc Zyngier maz@kernel.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Tested-by: John Garry john.garry@huawei.com Link: https://lore.kernel.org/r/20220405185040.206297-2-maz@kernel.org
conflict: kernel/irq/msi.c
Signed-off-by: Chen Jiahao chenjiahao16@huawei.com Reviewed-by: Zhang Jianhua chris.zjh@huawei.com Reviewed-by: Liao Chang liaochang1@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- kernel/irq/msi.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index d217acc9f71b..77722ebdf6f5 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -456,6 +456,21 @@ int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, irqd_clr_can_reserve(irq_data); if (domain->flags & IRQ_DOMAIN_MSI_NOMASK_QUIRK) irqd_set_msi_nomask_quirk(irq_data); + + /* + * If the interrupt is managed but no CPU is available to + * service it, shut it down until better times. Note that + * we only do this on the !RESERVE path as x86 (the only + * architecture using this flag) deals with this in a + * different way by using a catch-all vector. + */ + 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); + return 0; + } } ret = irq_domain_activate_irq(irq_data, can_reserve); if (ret)