Re: [PATCH v1 2/2] x86/vmware: Decrypt steal-time storage before sharing it

[sashiko-bot@kernel.org]

> VMware's steal-time counter must be in shared memory so the host can
> update it. Encrypted guests currently register its address without
> decrypting the storage. Move their setup to an early initcall, when the
> memory allocator is available for page-table splitting, but before
> secondary CPUs start. Leave ordinary guests' setup unchanged.
> 
> Convert every possible CPU's storage before registering any address.
> Zero each object after conversion, since its contents may not survive
> conversion and the host initializes only the counter. Register the boot
> CPU with preemption disabled; the existing hotplug callbacks handle the
> others. If conversion or boot-CPU registration fails, attempt to re-encrypt
> all affected ranges, including a partially converted failing range, and
> disable steal time.
> 
> TDX's conversion path requires directly mapped memory. Check all per-CPU
> objects before converting anything, and disable steal time if a TDX guest
> uses the page per-CPU allocator, which supplies vmalloc mappings. This
> also covers automatic fallback from the embedded allocator. AMD guests
> are unaffected by this restriction because their conversion path supports
> those mappings.
> 
> Link: https://lore.kernel.org/r/20260309235250.2611115-5-alexey.makhalov@broadcom.com
> Co-developed-by: Bo Gan <bo.gan@broadcom.com>
> Signed-off-by: Bo Gan <bo.gan@broadcom.com>
> Co-developed-by: Alexey Makhalov <alexey.makhalov@broadcom.com>
> Signed-off-by: Alexey Makhalov <alexey.makhalov@broadcom.com>
> Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/cover.1789488039.git.zack.rusin@broadcom.com?part=2