linux-kernel - Re: [PATCH v5] mshv: Extend create partition ioctl to support cpu features

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20251113194754.GC1175882@liuwe-devbox-debian-v2.local>
Date: Thu, 13 Nov 2025 19:47:54 +0000
From: Wei Liu <wei.liu@...nel.org>
To: Nuno Das Neves <nunodasneves@...ux.microsoft.com>
Cc: linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org,
	wei.liu@...nel.org, mhklinux@...look.com, kys@...rosoft.com,
	haiyangz@...rosoft.com, decui@...rosoft.com, longli@...rosoft.com,
	skinsburskii@...ux.microsoft.com, prapal@...ux.microsoft.com,
	mrathor@...ux.microsoft.com, muislam@...rosoft.com,
	anrayabh@...ux.microsoft.com,
	Jinank Jain <jinankjain@...rosoft.com>
Subject: Re: [PATCH v5] mshv: Extend create partition ioctl to support cpu
 features

On Thu, Nov 13, 2025 at 11:45:33AM -0800, Nuno Das Neves wrote:
> From: Muminul Islam <muislam@...rosoft.com>
> 
> The existing mshv create partition ioctl does not provide a way to
> specify which cpu features are enabled in the guest. Instead, it
> attempts to enable all features and those that are not supported are
> silently disabled by the hypervisor.
> 
> This was done to reduce unnecessary complexity and is sufficient for
> many cases. However, new scenarios require fine-grained control over
> these features.
> 
> Define a new mshv_create_partition_v2 structure which supports
> passing the disabled processor and xsave feature bits through to the
> create partition hypercall directly.
> 
> Introduce a new flag MSHV_PT_BIT_CPU_AND_XSAVE_FEATURES which enables
> the new structure. If unset, the original mshv_create_partition struct
> is used, with the old behavior of enabling all features.
> 
> Co-developed-by: Jinank Jain <jinankjain@...rosoft.com>
> Signed-off-by: Jinank Jain <jinankjain@...rosoft.com>
> Signed-off-by: Muminul Islam <muislam@...rosoft.com>
> Signed-off-by: Nuno Das Neves <nunodasneves@...ux.microsoft.com>
> Reviewed-by: Michael Kelley <mhklinux@...look.com>

Queued to hyperv-next. Thanks!

Wei