This is a note to let you know that I've just added the patch titled xen/events: don't use chip_data for legacy IRQs to the 5.4-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: xen-events-don-t-use-chip_data-for-legacy-irqs.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 0891fb39ba67bd7ae023ea0d367297ffff010781 Mon Sep 17 00:00:00 2001 From: Juergen Gross <jgross@xxxxxxxx> Date: Wed, 30 Sep 2020 11:16:14 +0200 Subject: xen/events: don't use chip_data for legacy IRQs From: Juergen Gross <jgross@xxxxxxxx> commit 0891fb39ba67bd7ae023ea0d367297ffff010781 upstream. Since commit c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.") Xen is using the chip_data pointer for storing IRQ specific data. When running as a HVM domain this can result in problems for legacy IRQs, as those might use chip_data for their own purposes. Use a local array for this purpose in case of legacy IRQs, avoiding the double use. Cc: stable@xxxxxxxxxxxxxxx Fixes: c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.") Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Tested-by: Stefan Bader <stefan.bader@xxxxxxxxxxxxx> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200930091614.13660-1-jgross@xxxxxxxx Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/xen/events/events_base.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -91,6 +91,8 @@ static bool (*pirq_needs_eoi)(unsigned i /* Xen will never allocate port zero for any purpose. */ #define VALID_EVTCHN(chn) ((chn) != 0) +static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY]; + static struct irq_chip xen_dynamic_chip; static struct irq_chip xen_percpu_chip; static struct irq_chip xen_pirq_chip; @@ -155,7 +157,18 @@ int get_evtchn_to_irq(unsigned evtchn) /* Get info for IRQ */ struct irq_info *info_for_irq(unsigned irq) { - return irq_get_chip_data(irq); + if (irq < nr_legacy_irqs()) + return legacy_info_ptrs[irq]; + else + return irq_get_chip_data(irq); +} + +static void set_info_for_irq(unsigned int irq, struct irq_info *info) +{ + if (irq < nr_legacy_irqs()) + legacy_info_ptrs[irq] = info; + else + irq_set_chip_data(irq, info); } /* Constructors for packed IRQ information. */ @@ -376,7 +389,7 @@ static void xen_irq_init(unsigned irq) info->type = IRQT_UNBOUND; info->refcnt = -1; - irq_set_chip_data(irq, info); + set_info_for_irq(irq, info); list_add_tail(&info->list, &xen_irq_list_head); } @@ -425,14 +438,14 @@ static int __must_check xen_allocate_irq static void xen_free_irq(unsigned irq) { - struct irq_info *info = irq_get_chip_data(irq); + struct irq_info *info = info_for_irq(irq); if (WARN_ON(!info)) return; list_del(&info->list); - irq_set_chip_data(irq, NULL); + set_info_for_irq(irq, NULL); WARN_ON(info->refcnt > 0); @@ -602,7 +615,7 @@ EXPORT_SYMBOL_GPL(xen_irq_from_gsi); static void __unbind_from_irq(unsigned int irq) { int evtchn = evtchn_from_irq(irq); - struct irq_info *info = irq_get_chip_data(irq); + struct irq_info *info = info_for_irq(irq); if (info->refcnt > 0) { info->refcnt--; @@ -1106,7 +1119,7 @@ int bind_ipi_to_irqhandler(enum ipi_vect void unbind_from_irqhandler(unsigned int irq, void *dev_id) { - struct irq_info *info = irq_get_chip_data(irq); + struct irq_info *info = info_for_irq(irq); if (WARN_ON(!info)) return; @@ -1140,7 +1153,7 @@ int evtchn_make_refcounted(unsigned int if (irq == -1) return -ENOENT; - info = irq_get_chip_data(irq); + info = info_for_irq(irq); if (!info) return -ENOENT; @@ -1168,7 +1181,7 @@ int evtchn_get(unsigned int evtchn) if (irq == -1) goto done; - info = irq_get_chip_data(irq); + info = info_for_irq(irq); if (!info) goto done; Patches currently in stable-queue which might be from jgross@xxxxxxxx are queue-5.4/xen-events-don-t-use-chip_data-for-legacy-irqs.patch