From: Jan Beulich <JBeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"Wei Liu" <wl@xen.org>, "Roger Pau Monné" <roger.pau@citrix.com>
Subject: [Xen-devel] [PATCH v4 07/13] x86/IRQ: target online CPUs when binding guest IRQ
Date: Tue, 16 Jul 2019 07:41:37 +0000 [thread overview]
Message-ID: <d60f7c11-457f-798e-7a4f-b9164439f565@suse.com> (raw)
In-Reply-To: <5cda711a-b417-76e9-d113-ea838463f225@suse.com>
fixup_irqs() skips interrupts without action. Hence such interrupts can
retain affinity to just offline CPUs. With "noirqbalance" in effect,
pirq_guest_bind() so far would have left them alone, resulting in a non-
working interrupt.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
v3: New.
---
I've not observed this problem in practice - the change is just the
result of code inspection after having noticed action-less IRQs in 'i'
debug key output pointing at all parked/offline CPUs.
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -1703,9 +1703,27 @@ int pirq_guest_bind(struct vcpu *v, stru
desc->status |= IRQ_GUEST;
- /* Attempt to bind the interrupt target to the correct CPU. */
- if ( !opt_noirqbalance && (desc->handler->set_affinity != NULL) )
- desc->handler->set_affinity(desc, cpumask_of(v->processor));
+ /*
+ * Attempt to bind the interrupt target to the correct (or at least
+ * some online) CPU.
+ */
+ if ( desc->handler->set_affinity )
+ {
+ const cpumask_t *affinity = NULL;
+
+ if ( !opt_noirqbalance )
+ affinity = cpumask_of(v->processor);
+ else if ( !cpumask_intersects(desc->affinity, &cpu_online_map) )
+ {
+ cpumask_setall(desc->affinity);
+ affinity = &cpumask_all;
+ }
+ else if ( !cpumask_intersects(desc->arch.cpu_mask,
+ &cpu_online_map) )
+ affinity = desc->affinity;
+ if ( affinity )
+ desc->handler->set_affinity(desc, affinity);
+ }
desc->status &= ~IRQ_DISABLED;
desc->handler->startup(desc);
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next prev parent reply other threads:[~2019-07-16 7:46 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-16 7:24 [Xen-devel] [PATCH v4 00/13] x86: IRQ management adjustments Jan Beulich
2019-07-16 7:37 ` [Xen-devel] [PATCH v4 01/13] x86/IRQ: deal with move-in-progress state in fixup_irqs() Jan Beulich
2019-07-19 13:20 ` Andrew Cooper
2019-07-16 7:37 ` [Xen-devel] [PATCH v4 02/13] x86/IRQ: deal with move cleanup count " Jan Beulich
2019-07-16 7:38 ` [Xen-devel] [PATCH v4 03/13] x86/IRQ: desc->affinity should strictly represent the requested value Jan Beulich
2019-07-19 13:25 ` Andrew Cooper
2019-07-16 7:38 ` [Xen-devel] [PATCH v4 04/13] x86/IRQ: consolidate use of ->arch.cpu_mask Jan Beulich
2019-07-16 7:39 ` [Xen-devel] [PATCH v4 05/13] x86/IRQ: fix locking around vector management Jan Beulich
2019-07-16 7:40 ` [Xen-devel] [PATCH v4 06/13] x86/IOMMU: don't restrict IRQ affinities to online CPUs Jan Beulich
2019-07-16 9:12 ` Roger Pau Monné
2019-07-16 10:20 ` Jan Beulich
2019-07-16 11:17 ` Roger Pau Monné
2019-07-19 13:27 ` Andrew Cooper
2019-07-24 0:53 ` Tian, Kevin
2019-07-24 19:53 ` Woods, Brian
2019-07-16 7:41 ` Jan Beulich [this message]
2019-07-16 7:42 ` [Xen-devel] [PATCH v4 08/13] x86/IRQs: correct/tighten vector check in _clear_irq_vector() Jan Beulich
2019-07-16 7:42 ` [Xen-devel] [PATCH v4 09/13] x86/IRQ: make fixup_irqs() skip unconnected internally used interrupts Jan Beulich
2019-07-16 7:43 ` [Xen-devel] [PATCH v4 10/13] x86/IRQ: drop redundant cpumask_empty() from move_masked_irq() Jan Beulich
2019-07-16 7:43 ` [Xen-devel] [PATCH v4 11/13] x86/IRQ: tighten vector checks Jan Beulich
2019-07-16 7:44 ` [Xen-devel] [PATCH v4 12/13] x86/IRQ: eliminate some on-stack cpumask_t instances Jan Beulich
2019-07-16 7:45 ` [Xen-devel] [PATCH v4 13/13] x86/IRQ: move {,_}clear_irq_vector() Jan Beulich
2019-07-19 12:36 ` [Xen-devel] [PATCH v4 00/13] x86: IRQ management adjustments Andrew Cooper
2019-07-19 13:04 ` Jan Beulich
2019-07-19 13:13 ` Andrew Cooper
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