From: Paul Durrant <xadimgnik@gmail.com>
To: "'Julien Grall'" <julien@xen.org>, <xen-devel@lists.xenproject.org>
Cc: hongyxia@amazon.co.uk, iwj@xenproject.org,
"'Julien Grall'" <jgrall@amazon.com>,
"'Jan Beulich'" <jbeulich@suse.com>,
"'Andrew Cooper'" <andrew.cooper3@citrix.com>,
"'Roger Pau Monné'" <roger.pau@citrix.com>,
"'Wei Liu'" <wl@xen.org>
Subject: RE: [for-4.15][PATCH v2 1/5] xen/x86: p2m: Don't map the special pages in the IOMMU page-tables
Date: Tue, 9 Feb 2021 20:19:56 -0000 [thread overview]
Message-ID: <04f301d6ff20$efa93b10$cefbb130$@xen.org> (raw)
In-Reply-To: <20210209152816.15792-2-julien@xen.org>
> -----Original Message-----
> From: Xen-devel <xen-devel-bounces@lists.xenproject.org> On Behalf Of Julien Grall
> Sent: 09 February 2021 15:28
> To: xen-devel@lists.xenproject.org
> Cc: hongyxia@amazon.co.uk; iwj@xenproject.org; Julien Grall <jgrall@amazon.com>; Jan Beulich
> <jbeulich@suse.com>; Andrew Cooper <andrew.cooper3@citrix.com>; Roger Pau Monné
> <roger.pau@citrix.com>; Wei Liu <wl@xen.org>
> Subject: [for-4.15][PATCH v2 1/5] xen/x86: p2m: Don't map the special pages in the IOMMU page-tables
>
> From: Julien Grall <jgrall@amazon.com>
>
> Currently, the IOMMU page-tables will be populated early in the domain
> creation if the hardware is able to virtualize the local APIC. However,
> the IOMMU page tables will not be freed during early failure and will
> result to a leak.
>
> An assigned device should not need to DMA into the vLAPIC page, so we
> can avoid to map the page in the IOMMU page-tables.
>
> This statement is also true for any special pages (the vLAPIC page is
> one of them). So to take the opportunity to prevent the mapping for all
> of them.
>
> Note that:
> - This is matching the existing behavior with PV guest
> - This doesn't change the behavior when the P2M is shared with the
> IOMMU. IOW, the special pages will still be accessibled by the
> device.
>
> Suggested-by: Jan Beulich <jbeulich@suse.com>
> Signed-off-by: Julien Grall <jgrall@amazon.com>
>
Reviewed-by: Paul Durrant <paul@xen.org>
next prev parent reply other threads:[~2021-02-09 20:20 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 15:28 [for-4.15][PATCH v2 0/5] xen/iommu: Collection of bug fixes for IOMMU teadorwn Julien Grall
2021-02-09 15:28 ` [for-4.15][PATCH v2 1/5] xen/x86: p2m: Don't map the special pages in the IOMMU page-tables Julien Grall
2021-02-09 20:19 ` Paul Durrant [this message]
2021-02-10 8:29 ` Roger Pau Monné
2021-02-10 8:50 ` Julien Grall
2021-02-10 9:34 ` Julien Grall
2021-02-10 11:10 ` Jan Beulich
2021-02-10 11:34 ` Roger Pau Monné
2021-02-10 11:38 ` Jan Beulich
2021-02-10 11:40 ` Julien Grall
2021-02-10 11:45 ` Jan Beulich
2021-02-10 11:48 ` Julien Grall
2021-02-10 11:54 ` Roger Pau Monné
2021-02-10 13:12 ` Jan Beulich
2021-02-10 15:24 ` Roger Pau Monné
2021-02-10 15:53 ` Jan Beulich
2021-02-10 13:08 ` Jan Beulich
2021-02-10 11:26 ` Jan Beulich
2021-02-15 11:38 ` Julien Grall
2021-02-15 12:36 ` Jan Beulich
2021-02-15 12:54 ` Julien Grall
2021-02-15 13:14 ` Jan Beulich
2021-02-17 11:21 ` Julien Grall
2021-02-09 15:28 ` [for-4.15][PATCH v2 2/5] xen/iommu: Check if the IOMMU was initialized before tearing down Julien Grall
2021-02-09 20:22 ` Paul Durrant
2021-02-17 11:25 ` Julien Grall
2021-02-09 15:28 ` [for-4.15][PATCH v2 3/5] xen/iommu: iommu_map: Don't crash the domain if it is dying Julien Grall
2021-02-09 20:28 ` Paul Durrant
2021-02-09 21:14 ` Julien Grall
2021-02-10 14:14 ` Jan Beulich
2021-02-10 14:58 ` Julien Grall
2021-02-10 15:56 ` Jan Beulich
2021-02-09 15:28 ` [for-4.15][PATCH v2 4/5] xen/iommu: x86: Don't leak the IOMMU page-tables Julien Grall
2021-02-09 20:33 ` Paul Durrant
2021-02-10 14:32 ` Jan Beulich
2021-02-10 15:04 ` Julien Grall
2021-02-10 16:12 ` Jan Beulich
2021-02-17 11:49 ` Julien Grall
2021-02-17 12:57 ` Jan Beulich
2021-02-10 14:44 ` Jan Beulich
2021-02-09 15:28 ` [for-4.15][PATCH v2 5/5] xen/iommu: x86: Clear the root page-table before freeing the page-tables Julien Grall
2021-02-09 20:36 ` Paul Durrant
2021-02-10 2:21 ` Tian, Kevin
2021-02-17 13:54 ` Julien Grall
2021-02-10 14:39 ` Jan Beulich
2021-02-09 16:47 ` [for-4.15][PATCH v2 0/5] xen/iommu: Collection of bug fixes for IOMMU teadorwn Ian Jackson
2021-02-17 11:33 ` Julien Grall
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