From: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
To: Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Don Brace <don.brace-dzo6w/eZyo2tG0bUXCXiUA@public.gmane.org>,
kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
Myron Stowe <myron.stowe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Subject: Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device gets context mapped
Date: Wed, 30 Nov 2016 15:26:43 +0100 [thread overview]
Message-ID: <20161130142642.GJ2078@8bytes.org> (raw)
In-Reply-To: <20161130102334.GC4192@x1>
On Wed, Nov 30, 2016 at 06:23:34PM +0800, Baoquan He wrote:
> OK, talked with Xunlei. The old cache could be entry with present bit
> set.
-EPARSE
Anyway, what I was trying to say is, that the IOMMU TLB is tagged with
domain-ids, and that there is also a context-cache which maps device-ids
to domain-ids.
If we update the context entry then we need to flush only the context
entry, as it will point to a new domain-id then and future IOTLB lookups
in the IOMMU will be using the new domain-id and do not match the old
entries.
Joerg
WARNING: multiple messages have this Message-ID (diff)
From: Joerg Roedel <joro@8bytes.org>
To: Baoquan He <bhe@redhat.com>
Cc: xlpang@redhat.com, Don Brace <don.brace@microsemi.com>,
Myron Stowe <myron.stowe@redhat.com>,
kexec@lists.infradead.org, LKML <linux-kernel@vger.kernel.org>,
iommu@lists.linux-foundation.org,
Myron Stowe <myron.stowe@gmail.com>,
Dave Young <dyoung@redhat.com>,
David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device gets context mapped
Date: Wed, 30 Nov 2016 15:26:43 +0100 [thread overview]
Message-ID: <20161130142642.GJ2078@8bytes.org> (raw)
In-Reply-To: <20161130102334.GC4192@x1>
On Wed, Nov 30, 2016 at 06:23:34PM +0800, Baoquan He wrote:
> OK, talked with Xunlei. The old cache could be entry with present bit
> set.
-EPARSE
Anyway, what I was trying to say is, that the IOMMU TLB is tagged with
domain-ids, and that there is also a context-cache which maps device-ids
to domain-ids.
If we update the context entry then we need to flush only the context
entry, as it will point to a new domain-id then and future IOTLB lookups
in the IOMMU will be using the new domain-id and do not match the old
entries.
Joerg
next prev parent reply other threads:[~2016-11-30 14:26 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 9:02 [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device gets context mapped Xunlei Pang
2016-11-16 9:02 ` Xunlei Pang
2016-11-16 9:02 ` Xunlei Pang
2016-11-16 9:13 ` Xunlei Pang
2016-11-16 9:13 ` Xunlei Pang
2016-11-16 9:13 ` Xunlei Pang
2016-11-16 14:58 ` Myron Stowe
2016-11-16 14:58 ` Myron Stowe
2016-11-16 14:58 ` Myron Stowe
2016-11-17 2:47 ` Xunlei Pang
2016-11-17 2:47 ` Xunlei Pang
2016-11-17 2:47 ` Xunlei Pang
[not found] ` <582D1A40.409-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-11-29 14:35 ` Joerg Roedel
2016-11-29 14:35 ` Joerg Roedel
2016-11-30 8:15 ` Xunlei Pang
2016-11-30 8:15 ` Xunlei Pang
2016-11-30 8:15 ` Xunlei Pang
2016-11-30 9:03 ` Baoquan He
2016-11-30 9:03 ` Baoquan He
2016-11-30 9:03 ` Baoquan He
2016-11-30 9:53 ` Baoquan He
2016-11-30 9:53 ` Baoquan He
2016-11-30 9:53 ` Baoquan He
2016-11-30 10:23 ` Baoquan He
2016-11-30 10:23 ` Baoquan He
2016-11-30 10:23 ` Baoquan He
2016-11-30 14:26 ` Joerg Roedel [this message]
2016-11-30 14:26 ` Joerg Roedel
2016-12-01 2:15 ` Xunlei Pang
2016-12-01 2:15 ` Xunlei Pang
2016-12-01 2:15 ` Xunlei Pang
[not found] ` <583F87D1.6030402-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-12-01 10:33 ` Joerg Roedel
2016-12-01 10:33 ` Joerg Roedel
2016-12-01 11:44 ` Xunlei Pang
2016-12-01 11:44 ` Xunlei Pang
2016-12-01 11:44 ` Xunlei Pang
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