From: George Dunlap <George.Dunlap@eu.citrix.com>
To: "Xu, Quan" <quan.xu@intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>, Feng Wu <feng.wu@intel.com>,
Jun Nakajima <jun.nakajima@intel.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Dario Faggioli <dario.faggioli@citrix.com>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
Jan Beulich <jbeulich@suse.com>,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Subject: Re: [PATCH v8 02/11] IOMMU/MMU: enhance the call trees of IOMMU unmapping and mapping
Date: Mon, 13 Jun 2016 17:36:57 +0100 [thread overview]
Message-ID: <CAFLBxZb9u_Q_GbfSazPDTRMTGmYDGX0VUKNiqs7PqnhJBiYzeg@mail.gmail.com> (raw)
In-Reply-To: <1465831038-43005-3-git-send-email-quan.xu@intel.com>
On Mon, Jun 13, 2016 at 4:17 PM, Xu, Quan <quan.xu@intel.com> wrote:
> From: Quan Xu <quan.xu@intel.com>
>
> When IOMMU mapping is failed, we issue a best effort rollback, stopping
> IOMMU mapping, unmapping the previous IOMMU maps and then reporting the
> error up to the call trees. When rollback is not feasible (in early
> initialization phase or trade-off of complexity) for the hardware domain,
> we do things on a best effort basis, only throwing out an error message.
>
> IOMMU unmapping should perhaps continue despite an error, in an attempt
> to do best effort cleanup.
>
> Signed-off-by: Quan Xu <quan.xu@intel.com>
> Reviewed-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> Acked-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Phew!
One comment...
> + while ( i-- )
> + /*
> + * IOMMU unmapping should perhaps continue despite an
> + * error in an attempt to do best effort cleanup, and
> + * consume the error as __must_check annotation.
> + */
> + if ( iommu_unmap_page(p2m->domain, gfn + i) )
> + continue;
I'd take out the "perhaps", (since there's no 'perhaps' about it) but
other than that I think this comment is fine.
It sounds like Jan had something more along the following in mind:
/* If statement to satisfy __must_check */
Either one works. The shorter one is sufficient, but the longer one
isn't too much I don't think.
-George
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next prev parent reply other threads:[~2016-06-13 16:36 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-13 15:17 [PATCH v8 00/11] Check VT-d Device-TLB flush error Xu, Quan
2016-06-13 15:17 ` [PATCH v8 01/11] IOMMU: handle IOMMU mapping and unmapping failures Xu, Quan
2016-06-13 15:17 ` [PATCH v8 02/11] IOMMU/MMU: enhance the call trees of IOMMU unmapping and mapping Xu, Quan
2016-06-13 15:36 ` Jan Beulich
2016-06-13 16:36 ` George Dunlap [this message]
2016-06-15 1:54 ` Xu, Quan
2016-06-15 7:44 ` Jan Beulich
2016-06-15 8:15 ` Xu, Quan
2016-06-15 8:22 ` Tian, Kevin
2016-06-15 8:35 ` Xu, Quan
2016-06-15 8:42 ` Jan Beulich
2016-06-15 8:53 ` Xu, Quan
2016-06-13 15:17 ` [PATCH v8 03/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU unmapping (top level ones) Xu, Quan
2016-06-13 15:17 ` [PATCH v8 04/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU mapping " Xu, Quan
2016-06-15 8:26 ` Xu, Quan
2016-06-16 9:19 ` Julien Grall
2016-06-13 15:17 ` [PATCH v8 05/11] IOMMU/MMU: propagate IOMMU Device-TLB flush error up to iommu_iotlb_flush{, _all} " Xu, Quan
2016-06-13 15:17 ` [PATCH v8 06/11] propagate IOMMU Device-TLB flush error up to EPT update " Xu, Quan
2016-06-13 16:37 ` George Dunlap
2016-06-13 15:17 ` [PATCH v8 07/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU suspending " Xu, Quan
2016-06-13 15:17 ` [PATCH v8 08/11] IOMMU: propagate IOMMU Device-TLB flush error (leaf ones) Xu, Quan
2016-06-16 9:25 ` Julien Grall
2016-06-13 15:17 ` [PATCH v8 09/11] vt-d: fix the IOMMU flush issue Xu, Quan
2016-06-13 15:52 ` Jan Beulich
2016-06-14 8:10 ` Xu, Quan
2016-06-14 8:26 ` Jan Beulich
2016-06-14 9:04 ` Xu, Quan
2016-06-15 1:42 ` Tian, Kevin
2016-06-13 15:17 ` [PATCH v8 10/11] vt-d: propagate the IOMMU Device-TLB flush error up to ME phantom functions Xu, Quan
2016-06-13 15:17 ` [PATCH v8 11/11] vt-d: add __must_check annotation to IOMMU flush pointers and handlers Xu, Quan
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