linux-kernel - Re: [PATCH v2] mshv: Align huge page stride with guest mapping

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Message-ID: <f46b9c60-a1d5-4d2c-9aaa-d4ba738f1491@linux.microsoft.com>
Date: Thu, 8 Jan 2026 12:03:19 -0800
From: Nuno Das Neves <nunodasneves@...ux.microsoft.com>
To: Stanislav Kinsburskii <skinsburskii@...ux.microsoft.com>,
 kys@...rosoft.com, haiyangz@...rosoft.com, wei.liu@...nel.org,
 decui@...rosoft.com, longli@...rosoft.com
Cc: linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] mshv: Align huge page stride with guest mapping

On 1/7/2026 10:45 AM, Stanislav Kinsburskii wrote:
> Ensure that a stride larger than 1 (huge page) is only used when page
> points to a head of a huge page and both the guest frame number (gfn) and
> the operation size (page_count) are aligned to the huge page size
> (PTRS_PER_PMD). This matches the hypervisor requirement that map/unmap
> operations for huge pages must be guest-aligned and cover a full huge page.
> 
> Add mshv_chunk_stride() to encapsulate this alignment and page-order
> validation, and plumb a huge_page flag into the region chunk handlers.
> This prevents issuing large-page map/unmap/share operations that the
> hypervisor would reject due to misaligned guest mappings.
> 
> Fixes: abceb4297bf8 ("mshv: Fix huge page handling in memory region traversal")
> Signed-off-by: Stanislav Kinsburskii <skinsburskii@...ux.microsoft.com>
> ---
>  drivers/hv/mshv_regions.c |   93 ++++++++++++++++++++++++++++++---------------
>  1 file changed, 62 insertions(+), 31 deletions(-)
> 

Reviewed-by: Nuno Das Neves <nunodasneves@...ux.microsoft.com>