From: Julien Grall <julien.grall@arm.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Kevin Tian <kevin.tian@intel.com>,
Stefano Stabellini <sstabellini@kernel.org>,
Steve Capper <Steve.Capper@arm.com>,
dario.faggioli@citrix.com, xen-devel@lists.xen.org,
Quan Xu <quan.xu@intel.com>
Subject: Re: [PATCH v7 05/11] IOMMU/MMU: propagate IOMMU Device-TLB flush error up to iommu_iotlb_flush{, _all} (top level ones)
Date: Thu, 9 Jun 2016 13:03:33 +0100 [thread overview]
Message-ID: <57595B15.9020308@arm.com> (raw)
In-Reply-To: <5759731702000078000F3671@prv-mh.provo.novell.com>
On 09/06/16 12:45, Jan Beulich wrote:
>>>> On 09.06.16 at 13:12, <julien.grall@arm.com> wrote:
>> On 08/06/16 09:58, Xu, Quan wrote:
>>> From: Quan Xu <quan.xu@intel.com>
>>>
>>> Signed-off-by: Quan Xu <quan.xu@intel.com>
>>> Reviewed-by: Jan Beulich <jbeulich@suse.com>
>>>
>>> CC: Stefano Stabellini <sstabellini@kernel.org>
>>> CC: Julien Grall <julien.grall@arm.com>
>>> CC: Jan Beulich <jbeulich@suse.com>
>>> CC: Kevin Tian <kevin.tian@intel.com>
>>> ---
>>> xen/arch/arm/p2m.c | 4 +++-
>>> xen/common/memory.c | 12 ++++++++++--
>>> xen/drivers/passthrough/iommu.c | 13 +++++++++----
>>> xen/drivers/passthrough/x86/iommu.c | 5 +++--
>>> xen/include/xen/iommu.h | 5 +++--
>>> 5 files changed, 28 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
>>> index 6a19c57..65d8f1a 100644
>>> --- a/xen/arch/arm/p2m.c
>>> +++ b/xen/arch/arm/p2m.c
>>> @@ -1178,7 +1178,9 @@ out:
>>> if ( flush )
>>> {
>>> flush_tlb_domain(d);
>>> - iommu_iotlb_flush(d, sgfn, egfn - sgfn);
>>> + ret = iommu_iotlb_flush(d, sgfn, egfn - sgfn);
>>
>> Sorry for coming late in the discussion. What kind of error do you
>> expect to return with iommu_tlb_flush?
>>
>> Today the ARM SMMU will always return 0 if the TLB flush timeout (see
>> arm_smmu_tlb_inv_context).
>>
>> We may want in the future to return an error when it has timeout,
>> however only returning an error is not safe at all. The TLB may contain
>> entries which are invalid (because we remove the mapping earlier) and a
>> device/domain could take advantage of that.
>>
>> So I am not sure if we should let running the guest when a flush has
>> timeout. Any thoughts?
>
> Well, did you look at the rest of this series, and the other dependent
> one? Guests (other than Dom0) get crashed when a flush times out. I
> guess that's what you will want on ARM then too.
I have found a call to domain_crash in iommu_map_page and
iommu_unmap_page. However, I have not found any for iommu_tlb_flush.
iommu_unmap_page and iommu_map_page are not called in the p2m code
because the page table are shared with the SMMU. So guest will not be
crashed if the timeout has failed.
Regards,
--
Julien Grall
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next prev parent reply other threads:[~2016-06-09 12:03 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-08 8:58 [PATCH v7 00/11] Check VT-d Device-TLB flush error Xu, Quan
2016-06-08 8:58 ` [PATCH v7 01/11] IOMMU: handle IOMMU mapping and unmapping failures Xu, Quan
2016-06-08 8:58 ` [PATCH v7 02/11] IOMMU/MMU: enhance the call trees of IOMMU unmapping and mapping Xu, Quan
2016-06-08 14:40 ` Jan Beulich
[not found] ` <57584D8602000078000F32D0@prv-mh.provo.novell.com>
[not found] ` <421857ad-4f6b-e99c-1e81-034b19effdfb@amd.com>
2016-06-10 6:56 ` Jan Beulich
2016-06-12 6:41 ` Tian, Kevin
2016-06-08 8:58 ` [PATCH v7 03/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU unmapping (top level ones) Xu, Quan
2016-06-08 14:42 ` Jan Beulich
2016-06-08 14:54 ` Jan Beulich
2016-06-09 19:30 ` Suravee Suthikulanit
2016-06-09 10:28 ` Julien Grall
2016-06-08 8:58 ` [PATCH v7 04/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU mapping " Xu, Quan
2016-06-08 14:43 ` Jan Beulich
2016-06-09 18:45 ` Suravee Suthikulanit
2016-06-09 10:30 ` Julien Grall
2016-06-08 8:58 ` [PATCH v7 05/11] IOMMU/MMU: propagate IOMMU Device-TLB flush error up to iommu_iotlb_flush{, _all} " Xu, Quan
2016-06-09 11:12 ` Julien Grall
2016-06-09 11:45 ` Jan Beulich
2016-06-09 12:03 ` Julien Grall [this message]
2016-06-09 12:08 ` Julien Grall
2016-06-09 12:15 ` Jan Beulich
2016-06-09 12:24 ` Julien Grall
2016-06-09 12:32 ` Jan Beulich
2016-06-09 12:39 ` Julien Grall
2016-06-12 6:55 ` Tian, Kevin
2016-06-12 7:02 ` Xu, Quan
2016-06-12 15:35 ` Julien Grall
2016-06-09 12:14 ` Jan Beulich
2016-06-12 6:46 ` Tian, Kevin
2016-06-08 8:58 ` [PATCH v7 06/11] propagate IOMMU Device-TLB flush error up to EPT update " Xu, Quan
2016-06-08 8:59 ` [PATCH v7 07/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU suspending " Xu, Quan
2016-06-08 14:51 ` Jan Beulich
2016-06-12 7:42 ` Xu, Quan
2016-06-13 9:25 ` Jan Beulich
2016-06-09 18:58 ` Suravee Suthikulanit
2016-06-12 6:58 ` Tian, Kevin
2016-06-08 8:59 ` [PATCH v7 08/11] IOMMU: propagate IOMMU Device-TLB flush error (leaf ones) Xu, Quan
2016-06-08 8:59 ` [PATCH v7 09/11] vt-d: fix the IOMMU flush issue Xu, Quan
2016-06-12 7:32 ` Tian, Kevin
2016-06-12 9:27 ` Xu, Quan
2016-06-13 8:50 ` Xu, Quan
2016-06-08 8:59 ` [PATCH v7 10/11] vt-d: propagate the IOMMU Device-TLB flush error up to ME phantom functions Xu, Quan
2016-06-12 7:34 ` Tian, Kevin
2016-06-08 8:59 ` [PATCH v7 11/11] vt-d: add __must_check annotation to IOMMU flush pointers and handlers Xu, Quan
2016-06-12 7:35 ` Tian, Kevin
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