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,
wei@aristanetworks.com
Subject: Re: [PATCH v2] intel-iommu: Disable translation if already enabled
Date: Tue, 23 Apr 2013 14:49:27 +0200 [thread overview]
Message-ID: <20130423124926.GC2589@8bytes.org> (raw)
In-Reply-To: <1366706103-2640-1-git-send-email-indou.takao@jp.fujitsu.com>
On Tue, Apr 23, 2013 at 05:35:03PM +0900, Takao Indoh wrote:
> This patch disables translation(dma-remapping) before its initialization
> if it is already enabled.
>
> This is needed for kexec/kdump boot. If dma-remapping is enabled in the
> first kernel, it need to be disabled before initializing its page table
> during second kernel boot. Wei Hu also reported that this is needed
> when second kernel boots with intel_iommu=off.
>
> Basically iommu->gcmd is used to know whether translation is enabled or
> disabled, but it is always zero at boot time even when translation is
> enabled since iommu->gcmd is initialized without considering such a
> case. Therefor this patch synchronizes iommu->gcmd value with global
> command register when iommu structure is allocated.
>
> Changelog:
> v2:
> - Change subject and patch description
> - Disable translation after dmar_table_init() so that it works when
> intel_iommu=off is specified.
>
> v1:
> https://lkml.org/lkml/2013/3/20/707
>
> Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com>
> ---
> drivers/iommu/dmar.c | 11 ++++++++++-
> drivers/iommu/intel-iommu.c | 15 +++++++++++++++
> 2 files changed, 25 insertions(+), 1 deletions(-)
Looks good to me, applied to x86/vt-d, thanks Takao.
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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,
wei-BGArkANP9klv6pq1l3V1OdBPR1lH4CV8@public.gmane.org
Subject: Re: [PATCH v2] intel-iommu: Disable translation if already enabled
Date: Tue, 23 Apr 2013 14:49:27 +0200 [thread overview]
Message-ID: <20130423124926.GC2589@8bytes.org> (raw)
In-Reply-To: <1366706103-2640-1-git-send-email-indou.takao-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
On Tue, Apr 23, 2013 at 05:35:03PM +0900, Takao Indoh wrote:
> This patch disables translation(dma-remapping) before its initialization
> if it is already enabled.
>
> This is needed for kexec/kdump boot. If dma-remapping is enabled in the
> first kernel, it need to be disabled before initializing its page table
> during second kernel boot. Wei Hu also reported that this is needed
> when second kernel boots with intel_iommu=off.
>
> Basically iommu->gcmd is used to know whether translation is enabled or
> disabled, but it is always zero at boot time even when translation is
> enabled since iommu->gcmd is initialized without considering such a
> case. Therefor this patch synchronizes iommu->gcmd value with global
> command register when iommu structure is allocated.
>
> Changelog:
> v2:
> - Change subject and patch description
> - Disable translation after dmar_table_init() so that it works when
> intel_iommu=off is specified.
>
> v1:
> https://lkml.org/lkml/2013/3/20/707
>
> Signed-off-by: Takao Indoh <indou.takao-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
> ---
> drivers/iommu/dmar.c | 11 ++++++++++-
> drivers/iommu/intel-iommu.c | 15 +++++++++++++++
> 2 files changed, 25 insertions(+), 1 deletions(-)
Looks good to me, applied to x86/vt-d, thanks Takao.
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,
wei@aristanetworks.com
Subject: Re: [PATCH v2] intel-iommu: Disable translation if already enabled
Date: Tue, 23 Apr 2013 14:49:27 +0200 [thread overview]
Message-ID: <20130423124926.GC2589@8bytes.org> (raw)
In-Reply-To: <1366706103-2640-1-git-send-email-indou.takao@jp.fujitsu.com>
On Tue, Apr 23, 2013 at 05:35:03PM +0900, Takao Indoh wrote:
> This patch disables translation(dma-remapping) before its initialization
> if it is already enabled.
>
> This is needed for kexec/kdump boot. If dma-remapping is enabled in the
> first kernel, it need to be disabled before initializing its page table
> during second kernel boot. Wei Hu also reported that this is needed
> when second kernel boots with intel_iommu=off.
>
> Basically iommu->gcmd is used to know whether translation is enabled or
> disabled, but it is always zero at boot time even when translation is
> enabled since iommu->gcmd is initialized without considering such a
> case. Therefor this patch synchronizes iommu->gcmd value with global
> command register when iommu structure is allocated.
>
> Changelog:
> v2:
> - Change subject and patch description
> - Disable translation after dmar_table_init() so that it works when
> intel_iommu=off is specified.
>
> v1:
> https://lkml.org/lkml/2013/3/20/707
>
> Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com>
> ---
> drivers/iommu/dmar.c | 11 ++++++++++-
> drivers/iommu/intel-iommu.c | 15 +++++++++++++++
> 2 files changed, 25 insertions(+), 1 deletions(-)
Looks good to me, applied to x86/vt-d, thanks Takao.
next prev parent reply other threads:[~2013-04-23 12:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-23 8:35 [PATCH v2] intel-iommu: Disable translation if already enabled Takao Indoh
2013-04-23 8:35 ` Takao Indoh
2013-04-23 8:35 ` Takao Indoh
2013-04-23 12:49 ` Joerg Roedel [this message]
2013-04-23 12:49 ` Joerg Roedel
2013-04-23 12:49 ` Joerg Roedel
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