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From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Stefano Stabellini <sstabellini@kernel.org>,
	Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Jiang Liu <jiang.liu@linux.intel.com>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	linux-kernel@vger.kernel.org, konrad.wilk@oracle.com,
	david.vrabel@citrix.com, jgross@suse.com
Subject: Re: Xen regression, Was: [PATCH] x86/irq: Probe for PIC presence before allocating descs for legacy IRQs
Date: Tue, 12 Apr 2016 09:22:34 -0400	[thread overview]
Message-ID: <570CF69A.1020701@oracle.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1604111901000.23347@sstabellini-ThinkPad-X260>

On 04/11/2016 10:08 PM, Stefano Stabellini wrote:
> Hi all,
>
> Unfortunately this patch (now commit
> 8c058b0b9c34d8c8d7912880956543769323e2d8) causes a regression on Xen
> when running on top of QEMU: the number of PIT irqs get set to 0 by
> probe_8259A but actually there are 16.
>
> Any suggestions on how to fix this?
>
> 1) we could revert 8c058b0b9c34d8c8d7912880956543769323e2d8
> 2) we could introduce an 'if (!xen_domain())' in probe_8259A
> 3) suggestions welcome

Stefano, do you have b4ff8389ed14b849354b59ce9b360bdefcdbf99c ?

It was supposed to fix this problem for Xen. However, I just noticed 
that arch/arm64/include/asm/irq.h makes nr_legacy_irqs() return 0 
(unlike arch/arm/include/asm/irq.h). Could that be the problem?


-boris

  parent reply	other threads:[~2016-04-12 13:23 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-02 13:24 [PATCH] x86/irq: Probe for PIC presence before allocating descs for legacy IRQs Vitaly Kuznetsov
2015-11-02 19:09 ` Thomas Gleixner
2016-04-12  2:08 ` Xen regression, Was: " Stefano Stabellini
2016-04-12  8:37   ` Vitaly Kuznetsov
2016-04-12 13:22   ` Boris Ostrovsky [this message]
2016-04-12 18:06     ` Stefano Stabellini
2016-04-12 19:02       ` Boris Ostrovsky
2016-04-12 21:14         ` Stefano Stabellini
2016-04-12 21:34           ` Boris Ostrovsky
2016-04-12 21:56             ` Stefano Stabellini
2016-04-12 22:33               ` Boris Ostrovsky
2016-04-12 23:15                 ` Stefano Stabellini
2016-04-13  1:27                   ` Boris Ostrovsky
2016-04-13 17:36                     ` Boris Ostrovsky
2016-04-13 19:10                       ` Boris Ostrovsky
2016-04-13 22:28                         ` Luis R. Rodriguez
2016-04-13 22:38                         ` Stefano Stabellini
2016-04-14 12:45                           ` Boris Ostrovsky
2016-04-14 13:45       ` David Vrabel
2016-04-14 14:46         ` Boris Ostrovsky

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