linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: Gavin Shan <gshan@redhat.com>
Cc: kernel-team@android.com, Suzuki Poulose <suzuki.poulose@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Quentin Perret <qperret@google.com>,
	James Morse <james.morse@arm.com>, Will Deacon <will@kernel.org>,
	kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 00/21] KVM: arm64: Rewrite page-table code and fault handling
Date: Fri, 04 Sep 2020 11:07:50 +0100	[thread overview]
Message-ID: <fa494886b9a88ec7b02141f2da44d5a7@kernel.org> (raw)
In-Reply-To: <5aa43d21-30a1-68c8-2620-60a25e4edfa2@redhat.com>

On 2020-09-04 01:51, Gavin Shan wrote:
> Hi Will,
> 
> On 9/3/20 10:16 PM, Will Deacon wrote:
>> On Thu, Sep 03, 2020 at 09:48:18PM +1000, Gavin Shan wrote:
>>> On 9/3/20 9:13 PM, Gavin Shan wrote:
>>>> On 9/3/20 5:34 PM, Gavin Shan wrote:
>>>>> On 8/25/20 7:39 PM, Will Deacon wrote:
>>>>>> Hello folks,
>>>>>> 
>>>>>> This is version three of the KVM page-table rework that I 
>>>>>> previously posted
>>>>>> here:
>>>>>> 
>>>>>>     v1: 
>>>>>> https://lore.kernel.org/r/20200730153406.25136-1-will@kernel.org
>>>>>>     v2: 
>>>>>> https://lore.kernel.org/r/20200818132818.16065-1-will@kernel.org
>>>>>> 
>>>>>> Changes since v2 include:
>>>>>> 
>>>>>>     * Rebased onto -rc2, which includes the conflicting OOM 
>>>>>> blocking fixes
>>>>>>     * Dropped the patch trying to "fix" the memcache in 
>>>>>> kvm_phys_addr_ioremap()
>>>>>> 
>>>>> 
>>>>> It's really nice work, making the code unified/simplified greatly.
>>>>> However, it seems it doesn't work well with HugeTLBfs. Please refer
>>>>> to the following test result and see if you have quick idea, or I
>>>>> can debug it a bit :)
>> 
>> Nice testing matrix, and thanks for reporting the problem!
>> 
>>>>> Machine         Host                     Guest              Result
>>>>> ===============================================================
>>>>> ThunderX2    VA_BITS:   42           PAGE_SIZE:  4KB     Passed
>>>>>                PAGE_SIZE: 64KB                    64KB     passed
>>>>>                THP:       disabled
>>>>>                HugeTLB:   disabled
>>>>> ---------------------------------------------------------------
>>>>> ThunderX2    VA_BITS:   42           PAGE_SIZE:  4KB     Passed
>>>>>                PAGE_SIZE: 64KB                    64KB     passed
>>>>>                THP:       enabled
>>>>>                HugeTLB:   disabled
>>>>> ----------------------------------------------------------------
>>>>> ThunderX2    VA_BITS:   42           PAGE_SIZE:  4KB     Fail[1]
>>>>>                PAGE_SIZE: 64KB                    64KB     Fail[1]
>>>>>                THP:       disabled
>>>>>                HugeTLB:   enabled
>>>>> ---------------------------------------------------------------
>>>>> ThunderX2    VA_BITS:   39           PAGE_SIZE:  4KB     Passed
>>>>>                PAGE_SIZE: 4KB                     64KB     Passed
>>>>>                THP:       disabled
>>>>>                HugeTLB:   disabled
>>>>> ---------------------------------------------------------------
>>>>> ThunderX2    VA_BITS:   39           PAGE_SIZE:  4KB     Passed
>>>>>                PAGE_SIZE: 4KB                     64KB     Passed
>>>>>                THP:       enabled
>>>>>                HugeTLB:   disabled
>>>>> --------------------------------------------------------------
>>>>> ThunderX2    VA_BITS:   39           PAGE_SIZE: 4KB     Fail[2]
>>>>>                PAGE_SIZE: 4KB                    64KB     Fail[2]
>>>>>                THP:       disabled
>>>>>                HugeTLB:   enabled
>>>>> 
>>>> 
>>>> I debugged the code and found the issue is caused by the following
>>>> patch.
>>>> 
>>>> [PATCH v3 06/21] KVM: arm64: Add support for stage-2 map()/unmap() 
>>>> in generic page-table
>> 
>> (I think this is just a symptom of the page-table being out of whack)
>> 
>>> Sorry that the guest could hang sometimes with above changes. I have 
>>> no idea what
>>> has been happening before I'm going to debug for more.. I'm pasting 
>>> the used command
>>> and output from guest.
>> 
>> Can you try the diff below, please? I think we can end up sticking 
>> down a
>> huge-page-sized mapping at an unaligned address, which causes us both 
>> to
>> overmap and also to fail to use the huge granule for a block mapping.
>> 
> 
> Since the the following changes have been folded to v4, I reran the 
> test cases
> on v4 and everything works fine.

Thanks a lot for the great testing and reviewing effort!

<shameless ask>
Since you obviously have a test rig setup for this: does your TX2 
support 16kB
pages? If so, could you please do another run with this page size on the 
host?
</shameless ask>

Thanks again,

         M.
-- 
Jazz is not dead. It just smells funny...

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2020-09-04 10:09 UTC|newest]

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-25  9:39 [PATCH v3 00/21] KVM: arm64: Rewrite page-table code and fault handling Will Deacon
2020-08-25  9:39 ` [PATCH v3 01/21] KVM: arm64: Remove kvm_mmu_free_memory_caches() Will Deacon
2020-08-25  9:39 ` [PATCH v3 02/21] KVM: arm64: Add stand-alone page-table walker infrastructure Will Deacon
2020-08-27 16:27   ` Alexandru Elisei
2020-08-28 15:43     ` Alexandru Elisei
2020-09-02 10:36     ` Will Deacon
2020-08-28 15:51   ` Alexandru Elisei
2020-09-02 10:49     ` Will Deacon
2020-09-02  6:31   ` Gavin Shan
2020-09-02 11:02     ` Will Deacon
2020-09-03  1:11       ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 03/21] KVM: arm64: Add support for creating kernel-agnostic stage-1 page tables Will Deacon
2020-08-28 15:35   ` Alexandru Elisei
2020-09-02 10:06     ` Will Deacon
2020-08-25  9:39 ` [PATCH v3 04/21] KVM: arm64: Use generic allocator for hyp stage-1 page-tables Will Deacon
2020-08-28 16:32   ` Alexandru Elisei
2020-09-02 11:35     ` Will Deacon
2020-09-02 14:48       ` Alexandru Elisei
2020-08-25  9:39 ` [PATCH v3 05/21] KVM: arm64: Add support for creating kernel-agnostic stage-2 page tables Will Deacon
2020-09-02  6:40   ` Gavin Shan
2020-09-02 11:30     ` Will Deacon
2020-08-25  9:39 ` [PATCH v3 06/21] KVM: arm64: Add support for stage-2 map()/unmap() in generic page-table Will Deacon
2020-09-01 16:24   ` Alexandru Elisei
2020-09-02 11:46     ` Will Deacon
2020-09-03  2:57   ` Gavin Shan
2020-09-03  5:27     ` Gavin Shan
2020-09-03 11:18   ` Gavin Shan
2020-09-03 12:30     ` Will Deacon
2020-09-03 16:15       ` Will Deacon
2020-09-04  0:47         ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 07/21] KVM: arm64: Convert kvm_phys_addr_ioremap() to generic page-table API Will Deacon
2020-09-01 17:08   ` Alexandru Elisei
2020-09-02 11:48     ` Will Deacon
2020-09-03  3:57   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 08/21] KVM: arm64: Convert kvm_set_spte_hva() " Will Deacon
2020-09-02 15:37   ` Alexandru Elisei
2020-09-03 16:37     ` Will Deacon
2020-09-03  4:13   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 09/21] KVM: arm64: Convert unmap_stage2_range() " Will Deacon
2020-09-02 16:23   ` Alexandru Elisei
2020-09-02 18:44     ` Alexandru Elisei
2020-09-03 17:57     ` Will Deacon
2020-09-08 13:07       ` Alexandru Elisei
2020-09-09 10:57         ` Alexandru Elisei
2020-09-03  4:19   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 10/21] KVM: arm64: Add support for stage-2 page-aging in generic page-table Will Deacon
2020-09-03  4:33   ` Gavin Shan
2020-09-03 16:48     ` Will Deacon
2020-09-04  1:01       ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 11/21] KVM: arm64: Convert page-aging and access faults to generic page-table API Will Deacon
2020-09-03  4:37   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 12/21] KVM: arm64: Add support for stage-2 write-protect in generic page-table Will Deacon
2020-09-03  4:47   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 13/21] KVM: arm64: Convert write-protect operation to generic page-table API Will Deacon
2020-09-03  4:48   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 14/21] KVM: arm64: Add support for stage-2 cache flushing in generic page-table Will Deacon
2020-09-03  4:51   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 15/21] KVM: arm64: Convert memslot cache-flushing code to generic page-table API Will Deacon
2020-09-03  4:52   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 16/21] KVM: arm64: Add support for relaxing stage-2 perms in generic page-table code Will Deacon
2020-09-03  4:55   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 17/21] KVM: arm64: Convert user_mem_abort() to generic page-table API Will Deacon
2020-09-03  6:05   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 18/21] KVM: arm64: Check the pgt instead of the pgd when modifying page-table Will Deacon
2020-09-03  5:00   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 19/21] KVM: arm64: Remove unused page-table code Will Deacon
2020-09-03  6:02   ` Gavin Shan
2020-08-25  9:39 ` [PATCH v3 20/21] KVM: arm64: Remove unused 'pgd' field from 'struct kvm_s2_mmu' Will Deacon
2020-09-03  5:07   ` Gavin Shan
2020-09-03 16:50     ` Will Deacon
2020-09-04  0:59       ` Gavin Shan
2020-09-04 10:02         ` Marc Zyngier
2020-08-25  9:39 ` [PATCH v3 21/21] KVM: arm64: Don't constrain maximum IPA size based on host configuration Will Deacon
2020-09-03  5:09   ` Gavin Shan
2020-08-27 16:26 ` [PATCH v3 00/21] KVM: arm64: Rewrite page-table code and fault handling Alexandru Elisei
2020-09-01 16:15   ` Will Deacon
2020-09-03  7:34 ` Gavin Shan
2020-09-03 11:13   ` Gavin Shan
2020-09-03 11:48     ` Gavin Shan
2020-09-03 12:16       ` Will Deacon
2020-09-04  0:51         ` Gavin Shan
2020-09-04 10:07           ` Marc Zyngier [this message]
2020-09-05  3:56             ` Gavin Shan
2020-09-05  9:33               ` Marc Zyngier
2020-09-07  9:27           ` Will Deacon
2020-09-03 18:52 ` Will Deacon

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=fa494886b9a88ec7b02141f2da44d5a7@kernel.org \
    --to=maz@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=gshan@redhat.com \
    --cc=james.morse@arm.com \
    --cc=kernel-team@android.com \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=qperret@google.com \
    --cc=suzuki.poulose@arm.com \
    --cc=will@kernel.org \
    /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).