linux-kernel - Re: [V2 PATCH 3/6] KVM: selftests: x86: Add IS_ALIGNED/IS_PAGE

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Message-ID: <Y8cXvS2gKcK8tU2D@google.com>
Date:   Tue, 17 Jan 2023 21:48:45 +0000
From:   Sean Christopherson <seanjc@...gle.com>
To:     Vishal Annapurve <vannapurve@...gle.com>
Cc:     x86@...nel.org, kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-kselftest@...r.kernel.org, pbonzini@...hat.com,
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Subject: Re: [V2 PATCH 3/6] KVM: selftests: x86: Add
 IS_ALIGNED/IS_PAGE_ALIGNED helpers

On Mon, Dec 05, 2022, Vishal Annapurve wrote:
> Add IS_ALIGNED/IS_PAGE_ALIGNED helpers for selftests.
> 
> Signed-off-by: Vishal Annapurve <vannapurve@...gle.com>
> ---
>  tools/testing/selftests/kvm/include/kvm_util_base.h    | 3 +++
>  tools/testing/selftests/kvm/include/x86_64/processor.h | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index 4ad99f295f2a..7ba32471df50 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -170,6 +170,9 @@ extern enum vm_guest_mode vm_mode_default;
>  #define MIN_PAGE_SIZE		(1U << MIN_PAGE_SHIFT)
>  #define PTES_PER_MIN_PAGE	ptes_per_page(MIN_PAGE_SIZE)
>  
> +/* @a is a power of 2 value */
> +#define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)

IS_ALIGNED() is provided by tools/include/linux/bitmap.h

>  struct vm_guest_mode_params {
>  	unsigned int pa_bits;
>  	unsigned int va_bits;
> diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
> index 5d310abe6c3f..4d5dd9a467e1 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
> @@ -279,6 +279,7 @@ static inline unsigned int x86_model(unsigned int eax)
>  #define PAGE_SHIFT		12
>  #define PAGE_SIZE		(1ULL << PAGE_SHIFT)
>  #define PAGE_MASK		(~(PAGE_SIZE-1) & PHYSICAL_PAGE_MASK)
> +#define IS_PAGE_ALIGNED(x)	IS_ALIGNED(x, PAGE_SIZE)

I certainly don't object to adding IS_PAGE_ALIGNED(), but it's not needed for
this series.  Verifying that KVM doesn't allow an unaligned page conversion during
KVM_HC_MAP_GPA_RANGE belongs in a separate test+series, as that doesn't have a
strict dependency on UPM.

TL;DR: this patch can be dropped, for now at least.

>  #define HUGEPAGE_SHIFT(x)	(PAGE_SHIFT + (((x) - 1) * 9))
>  #define HUGEPAGE_SIZE(x)	(1UL << HUGEPAGE_SHIFT(x))
> -- 
> 2.39.0.rc0.267.gcb52ba06e7-goog
>