Messages in this thread | | | Subject | Re: [PATCH v6 1/4] KVM: arm64: Introduce cache maintenance callbacks for guest stage-2 | From | "wangyanan (Y)" <> | Date | Thu, 17 Jun 2021 17:43:23 +0800 |
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Hi Marc,
On 2021/6/17 16:44, Marc Zyngier wrote: > On Thu, 17 Jun 2021 09:22:51 +0100, > "wangyanan (Y)" <wangyanan55@huawei.com> wrote: >> >> >> On 2021/6/17 16:03, Marc Zyngier wrote: >>> On Thu, 17 Jun 2021 07:48:29 +0100, >>> "wangyanan (Y)" <wangyanan55@huawei.com> wrote: >>>> Hi Marc, >>>> >>>> On 2021/6/16 21:21, Marc Zyngier wrote: >>>>> Hi Yanan, >>>>> >>>>> On Wed, 16 Jun 2021 10:51:57 +0100, >>>>> Yanan Wang <wangyanan55@huawei.com> wrote: >>>>>> To prepare for performing guest CMOs in the fault handlers in pgtable.c, >>>>>> introduce two cache maintenance callbacks in struct kvm_pgtable_mm_ops. >>>>>> >>>>>> The new callbacks are specific for guest stage-2, so they will only be >>>>>> initialized in 'struct kvm_pgtable_mm_ops kvm_s2_mm_ops'. >>>>>> >>>>>> Signed-off-by: Yanan Wang <wangyanan55@huawei.com> >>>>>> --- >>>>>> arch/arm64/include/asm/kvm_pgtable.h | 7 +++++++ >>>>>> 1 file changed, 7 insertions(+) >>>>>> >>>>>> diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h >>>>>> index c3674c47d48c..302eca32e0af 100644 >>>>>> --- a/arch/arm64/include/asm/kvm_pgtable.h >>>>>> +++ b/arch/arm64/include/asm/kvm_pgtable.h >>>>>> @@ -44,6 +44,11 @@ typedef u64 kvm_pte_t; >>>>>> * in the current context. >>>>>> * @virt_to_phys: Convert a virtual address mapped in the current context >>>>>> * into a physical address. >>>>>> + * @flush_dcache: Clean data cache for a guest page address range before >>>>>> + * creating the corresponding stage-2 mapping. >>>>> Please don't reintroduce the word 'flush'. We are really trying to >>>>> move away from it as it doesn't describe what we want to do. >>>> I agree with this. I intended to make the names short and laconic, but this >>>> missed the information about the callback's actual behaviors. >>>>> Here this >>>>> should be 'clean_invalidate_dcache' which, despite being a mouthful, >>>>> describe accurately what we expect it to do. >>>> Sure, I will change the name as you suggested. >>>>> The comment is also missing the invalidate part, and we shouldn't >>>>> assume that this is only used for S2 mapping. >>>> Ok, will refine the comment. I think something like"Clean and invalidate the >>>> date cache for the specified memory address range" may be generic enough. >>>>>> + * @flush_icache: Invalidate instruction cache for a guest page address >>>>>> + * range before creating or updating the corresponding >>>>>> + * stage-2 mapping. >>>>> Same thing here; this should be 'invalidate_icache', and the comment >>>>> cleaned up. >>>> Thanks, I will also correct this part. >>>> >>>> Besides the callback names and comments, is there anything else that still >>>> needs some adjustment in the other three patches? :) >>> It looks pretty good so far, much nicer than the previous versions. >>> >>> I have a small nit on the last patch, which should be dead easy to >>> address. I'm currently running a bunch of tests, hopefully nothing bad >>> will come out of it. >>> >>> If you respin it shortly, that nothing fails, and unless someone >>> shouts, I'll queue it for -next. >> It would be nice, thanks! >> I will address the nit and respin the series soon. > By the way, what the status of your selftest series that originally > came with this series? Are you planning to respin it? It would be > useful to have something that checks for regressions, and that series > did seem to do the trick. Actually they have already gone into upstream, since v5.13-rc1. :) The path is tools/testing/selftests/kvm/kvm_page_table_test.c, so it will be much convenient to test a 5.13 kernel, you can also have a try.
I am using the original test data from v3 in the cover-letter because I think the test results will be almost the same with a different kernel.
Thanks, Yanan . > Thanks, > > M. >
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