From: Joerg Roedel <joro@8bytes.org>
To: Qian Cai <cai@lca.pw>
Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] iommu/amd: fix a race in fetch_pte()
Date: Wed, 29 Apr 2020 10:47:38 +0200 [thread overview]
Message-ID: <20200429084738.GM21900@8bytes.org> (raw)
In-Reply-To: <7D03A3E2-647B-4FAD-886D-EE2764EC1EDB@lca.pw>
Hi Qian,
On Mon, Apr 20, 2020 at 09:26:12AM -0400, Qian Cai wrote:
>
> No dice. There could be some other races. For example,
Okay, I think I know what is happening. The increase_address_space()
function increases the address space, but does not update the
DTE and does not flush the old DTE from the caches. But this needs to
happen before domain->pt_root is updated, because otherwise another CPU
can come along and map something into the increased address-space which
is not yet accessible by the device because the DTE is not updated yet.
Regards,
Joerg
next prev parent reply other threads:[~2020-04-29 8:47 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-07 2:12 [RFC PATCH] iommu/amd: fix a race in fetch_pte() Qian Cai
2020-04-07 15:36 ` Qian Cai
2020-04-08 14:19 ` Joerg Roedel
2020-04-14 1:36 ` Qian Cai
2020-04-17 1:42 ` Qian Cai
2020-04-18 12:10 ` Joerg Roedel
2020-04-18 13:01 ` Qian Cai
2020-04-18 18:34 ` Joerg Roedel
2020-04-20 2:07 ` Qian Cai
2020-04-20 13:26 ` Qian Cai
2020-04-29 8:47 ` Joerg Roedel [this message]
2020-04-29 11:20 ` Joerg Roedel
2020-04-30 1:04 ` Qian Cai
2020-05-03 13:04 ` Qian Cai
2020-05-03 18:39 ` Joerg Roedel
2020-05-03 19:12 ` Qian Cai
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