From: Joerg Roedel <joro@8bytes.org>
To: Takao Indoh <indou.takao@jp.fujitsu.com>
Cc: kexec@lists.infradead.org, iommu@lists.linux-foundation.org,
dwmw2@infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] intel-iommu: Synchronize gcmd value with global command register
Date: Tue, 2 Apr 2013 16:05:47 +0200 [thread overview]
Message-ID: <20130402140546.GA15687@8bytes.org> (raw)
In-Reply-To: <51591EEE.60401@jp.fujitsu.com>
On Mon, Apr 01, 2013 at 02:45:18PM +0900, Takao Indoh wrote:
> <Current flow on kdump boot>
> enable_IR
> intel_enable_irq_remapping
> iommu_disable_irq_remapping <== IRES/QIES/TES disabled here
> dmar_disable_qi <== do nothing
> dmar_enable_qi <== QIES enabled
> intel_setup_irq_remapping <== IRES enabled
But what we want to do here in the kdumo case is to disable translation
too, right? Because the former kernel might have translation and
irq-remapping enabled and the kdump kernel might be compiled without
support for dma-remapping. So if we don't disable translation here too
the kdump kernel is unable to do DMA.
I agree that disabling translation should be a bit more explicit instead
of the current code.
Joerg
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WARNING: multiple messages have this Message-ID (diff)
From: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
To: Takao Indoh <indou.takao-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
Cc: kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH] intel-iommu: Synchronize gcmd value with global command register
Date: Tue, 2 Apr 2013 16:05:47 +0200 [thread overview]
Message-ID: <20130402140546.GA15687@8bytes.org> (raw)
In-Reply-To: <51591EEE.60401-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
On Mon, Apr 01, 2013 at 02:45:18PM +0900, Takao Indoh wrote:
> <Current flow on kdump boot>
> enable_IR
> intel_enable_irq_remapping
> iommu_disable_irq_remapping <== IRES/QIES/TES disabled here
> dmar_disable_qi <== do nothing
> dmar_enable_qi <== QIES enabled
> intel_setup_irq_remapping <== IRES enabled
But what we want to do here in the kdumo case is to disable translation
too, right? Because the former kernel might have translation and
irq-remapping enabled and the kdump kernel might be compiled without
support for dma-remapping. So if we don't disable translation here too
the kdump kernel is unable to do DMA.
I agree that disabling translation should be a bit more explicit instead
of the current code.
Joerg
WARNING: multiple messages have this Message-ID (diff)
From: Joerg Roedel <joro@8bytes.org>
To: Takao Indoh <indou.takao@jp.fujitsu.com>
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
dwmw2@infradead.org, kexec@lists.infradead.org
Subject: Re: [PATCH] intel-iommu: Synchronize gcmd value with global command register
Date: Tue, 2 Apr 2013 16:05:47 +0200 [thread overview]
Message-ID: <20130402140546.GA15687@8bytes.org> (raw)
In-Reply-To: <51591EEE.60401@jp.fujitsu.com>
On Mon, Apr 01, 2013 at 02:45:18PM +0900, Takao Indoh wrote:
> <Current flow on kdump boot>
> enable_IR
> intel_enable_irq_remapping
> iommu_disable_irq_remapping <== IRES/QIES/TES disabled here
> dmar_disable_qi <== do nothing
> dmar_enable_qi <== QIES enabled
> intel_setup_irq_remapping <== IRES enabled
But what we want to do here in the kdumo case is to disable translation
too, right? Because the former kernel might have translation and
irq-remapping enabled and the kdump kernel might be compiled without
support for dma-remapping. So if we don't disable translation here too
the kdump kernel is unable to do DMA.
I agree that disabling translation should be a bit more explicit instead
of the current code.
Joerg
next prev parent reply other threads:[~2013-04-02 14:05 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-21 1:32 [PATCH] intel-iommu: Synchronize gcmd value with global command register Takao Indoh
2013-03-21 1:32 ` Takao Indoh
2013-03-21 1:32 ` Takao Indoh
2013-03-26 14:46 ` Joerg Roedel
2013-03-26 14:46 ` Joerg Roedel
2013-03-26 14:46 ` Joerg Roedel
2013-03-27 5:02 ` Takao Indoh
2013-03-27 5:02 ` Takao Indoh
2013-03-27 5:02 ` Takao Indoh
2013-03-27 10:31 ` Joerg Roedel
2013-03-27 10:31 ` Joerg Roedel
2013-03-27 10:31 ` Joerg Roedel
2013-04-01 5:45 ` Takao Indoh
2013-04-01 5:45 ` Takao Indoh
2013-04-01 5:45 ` Takao Indoh
2013-04-02 14:05 ` Joerg Roedel [this message]
2013-04-02 14:05 ` Joerg Roedel
2013-04-02 14:05 ` Joerg Roedel
2013-04-03 7:11 ` Takao Indoh
2013-04-03 7:11 ` Takao Indoh
2013-04-03 7:11 ` Takao Indoh
2013-04-03 8:24 ` David Woodhouse
2013-04-03 8:24 ` David Woodhouse
2013-04-04 5:48 ` Takao Indoh
2013-04-04 5:48 ` Takao Indoh
2013-04-04 5:48 ` Takao Indoh
2013-04-04 14:24 ` David Woodhouse
2013-04-04 14:24 ` David Woodhouse
2013-04-04 14:24 ` David Woodhouse
2013-04-08 8:57 ` Takao Indoh
2013-04-08 8:57 ` Takao Indoh
2013-04-05 11:06 ` Joerg Roedel
2013-04-05 11:06 ` Joerg Roedel
2013-04-05 11:06 ` Joerg Roedel
2013-04-10 4:47 ` Takao Indoh
2013-04-10 4:47 ` Takao Indoh
2013-04-10 4:47 ` Takao Indoh
2013-04-15 9:00 ` Takao Indoh
2013-04-15 9:00 ` Takao Indoh
2013-04-15 9:00 ` Takao Indoh
2013-04-15 10:18 ` Joerg Roedel
2013-04-15 10:18 ` Joerg Roedel
2013-04-15 10:18 ` Joerg Roedel
2013-04-17 8:48 ` Takao Indoh
2013-04-17 8:48 ` Takao Indoh
2013-04-17 8:48 ` Takao Indoh
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