From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Ting-Wei Lan <lantw44@gmail.com>, xen-devel@lists.xen.org
Cc: Yang Zhang <yang.z.zhang@intel.com>,
Julien Grall <julien.grall@citrix.com>,
Kevin Tian <kevin.tian@intel.com>, Wei Liu <wei.liu2@citrix.com>,
Jan Beulich <jbeulich@suse.com>
Subject: Re: [PATCH v3] VT-d: add iommu=igfx option to workaround graphics issues
Date: Wed, 5 Aug 2015 13:18:05 +0100 [thread overview]
Message-ID: <55C1FEFD.4040205@citrix.com> (raw)
In-Reply-To: <1438765893-3123-1-git-send-email-lantw44@gmail.com>
On 05/08/15 10:11, Ting-Wei Lan wrote:
> When using Linux >= 3.19 (commit 47591df) as dom0 on some Intel Ironlake
> devices, It is possible to encounter graphics issues that make screen
> unreadable or crash the system. It was reported in freedesktop bugzilla:
>
> https://bugs.freedesktop.org/show_bug.cgi?id=90037
>
> As we still cannot find a proper fix for this problem, this patch adds
> iommu=igfx option to control whether Intel graphics IOMMU is enabled.
> Running Xen with iommu=no-igfx is similar to running Linux with
> intel_iommu=igfx_off, which disables IOMMU for Intel GPU. This can be
> used by users to manually workaround the problem before a fix is
> available for i915 driver.
>
> Signed-off-by: Ting-Wei Lan <lantw44@gmail.com>
> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Wei: I think this is a candidate for inclusion into 4.6
~Andrew
> ---
> Changed since v2:
> * Make no-igfx available for all Intel devices, not just Calpella/Ironlake
> Changed since v1:
> * Replace igfx_off with igfx
>
> docs/misc/xen-command-line.markdown | 11 ++++++++++-
> xen/drivers/passthrough/iommu.c | 3 +++
> xen/drivers/passthrough/vtd/quirks.c | 3 +++
> xen/include/xen/iommu.h | 2 +-
> 4 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
> index 13f03ad..486e53b 100644
> --- a/docs/misc/xen-command-line.markdown
> +++ b/docs/misc/xen-command-line.markdown
> @@ -793,7 +793,7 @@ debug hypervisor only).
> > Default: `new` unless directed-EOI is supported
>
> ### iommu
> -> `= List of [ <boolean> | force | required | intremap | qinval | snoop | sharept | dom0-passthrough | dom0-strict | amd-iommu-perdev-intremap | workaround_bios_bug | verbose | debug ]`
> +> `= List of [ <boolean> | force | required | intremap | qinval | snoop | sharept | dom0-passthrough | dom0-strict | amd-iommu-perdev-intremap | workaround_bios_bug | igfx | verbose | debug ]`
>
> > Sub-options:
>
> @@ -867,6 +867,15 @@ debug hypervisor only).
> >> ignored (normally IOMMU setup fails if any of the devices listed by a DRHD
> >> entry aren't PCI discoverable).
>
> +> `igfx` (VT-d)
> +
> +> Default: `true`
> +
> +>> Enable IOMMU for Intel graphics devices. The intended usage of this option
> +>> is `no-igfx`, which is silimar to Linux `intel_iommu=igfx_off` option used
> +>> to workaround graphics issues. If adding `no-igfx` fixes anything, you
> +>> should file a bug reporting the problem.
> +
> > `verbose`
>
> > Default: `false`
> diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
> index cc12735..966cc66 100644
> --- a/xen/drivers/passthrough/iommu.c
> +++ b/xen/drivers/passthrough/iommu.c
> @@ -47,6 +47,7 @@ bool_t __read_mostly force_iommu;
> bool_t __hwdom_initdata iommu_dom0_strict;
> bool_t __read_mostly iommu_verbose;
> bool_t __read_mostly iommu_workaround_bios_bug;
> +bool_t __read_mostly iommu_igfx = 1;
> bool_t __read_mostly iommu_passthrough;
> bool_t __read_mostly iommu_snoop = 1;
> bool_t __read_mostly iommu_qinval = 1;
> @@ -87,6 +88,8 @@ static void __init parse_iommu_param(char *s)
> force_iommu = val;
> else if ( !strcmp(s, "workaround_bios_bug") )
> iommu_workaround_bios_bug = val;
> + else if ( !strcmp(s, "igfx") )
> + iommu_igfx = val;
> else if ( !strcmp(s, "verbose") )
> iommu_verbose = val;
> else if ( !strcmp(s, "snoop") )
> diff --git a/xen/drivers/passthrough/vtd/quirks.c b/xen/drivers/passthrough/vtd/quirks.c
> index 69d29ab..92cff1d 100644
> --- a/xen/drivers/passthrough/vtd/quirks.c
> +++ b/xen/drivers/passthrough/vtd/quirks.c
> @@ -72,6 +72,9 @@ int is_igd_vt_enabled_quirk(void)
> {
> u16 ggc;
>
> + if ( !iommu_igfx )
> + return 0;
> +
> if ( !IS_ILK(ioh_id) )
> return 1;
>
> diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
> index 8eb764a..29eed51 100644
> --- a/xen/include/xen/iommu.h
> +++ b/xen/include/xen/iommu.h
> @@ -29,7 +29,7 @@
>
> extern bool_t iommu_enable, iommu_enabled;
> extern bool_t force_iommu, iommu_verbose;
> -extern bool_t iommu_workaround_bios_bug, iommu_passthrough;
> +extern bool_t iommu_workaround_bios_bug, iommu_igfx, iommu_passthrough;
> extern bool_t iommu_snoop, iommu_qinval, iommu_intremap;
> extern bool_t iommu_hap_pt_share;
> extern bool_t iommu_debug;
next prev parent reply other threads:[~2015-08-05 12:18 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-17 19:05 [PATCH] VT-d: add iommu=igfx_off option to workaround graphics issues Ting-Wei Lan
2015-07-17 19:36 ` Andrew Cooper
2015-07-18 8:46 ` 藍挺瑋
2015-07-19 15:53 ` Julien Grall
2015-07-20 8:27 ` Andrew Cooper
2015-07-20 10:19 ` Julien Grall
2015-07-20 1:28 ` Tian, Kevin
2015-07-20 8:21 ` Andrew Cooper
2015-07-20 10:44 ` Ting-Wei Lan
2015-07-21 0:57 ` Tian, Kevin
2015-07-21 6:56 ` Jan Beulich
2015-07-21 7:05 ` Tian, Kevin
2015-07-21 7:16 ` Jan Beulich
2015-07-21 7:23 ` Tian, Kevin
2015-07-21 7:33 ` Jan Beulich
2015-07-23 16:41 ` Ting-Wei Lan
2015-07-20 8:46 ` Jan Beulich
2015-07-25 16:57 ` [PATCH v2] VT-d: add iommu=igfx " Ting-Wei Lan
2015-07-26 16:47 ` Andrew Cooper
2015-07-31 1:26 ` Tian, Kevin
2015-07-31 8:37 ` Ting-Wei Lan
2015-08-04 2:00 ` Tian, Kevin
2015-08-05 9:11 ` [PATCH v3] " Ting-Wei Lan
2015-08-05 12:18 ` Andrew Cooper [this message]
2015-08-05 13:35 ` Wei Liu
2015-08-05 17:10 ` [PATCH v4] " Ting-Wei Lan
2015-08-06 0:49 ` Tian, Kevin
2015-08-06 8:25 ` Wei Liu
2015-08-06 9:28 ` Ian Campbell
2015-07-20 12:12 ` [PATCH] VT-d: add iommu=igfx_off " Andrew Cooper
2015-07-20 12:24 ` Jan Beulich
2015-07-20 12:34 ` Andrew Cooper
2015-07-20 13:55 ` Jan Beulich
2015-07-20 14:12 ` Andrew Cooper
2015-07-20 14:25 ` Jan Beulich
2015-07-21 1:15 ` Tian, Kevin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55C1FEFD.4040205@citrix.com \
--to=andrew.cooper3@citrix.com \
--cc=jbeulich@suse.com \
--cc=julien.grall@citrix.com \
--cc=kevin.tian@intel.com \
--cc=lantw44@gmail.com \
--cc=wei.liu2@citrix.com \
--cc=xen-devel@lists.xen.org \
--cc=yang.z.zhang@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).