linux-kernel - Re: [PATCH v2 1/2] KVM: x86: Add helper to retrieve current value of user return MSR

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Message-ID: <064c1240-e7f0-4061-a43a-9d05a46953a0@intel.com>
Date: Tue, 23 Sep 2025 11:58:55 +0800
From: Xiaoyao Li <xiaoyao.li@...el.com>
To: Sean Christopherson <seanjc@...gle.com>,
 Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
 Hou Wenlong <houwenlong.hwl@...group.com>,
 Lai Jiangshan <jiangshan.ljs@...group.com>
Subject: Re: [PATCH v2 1/2] KVM: x86: Add helper to retrieve current value of
 user return MSR

On 9/20/2025 5:38 AM, Sean Christopherson wrote:
> From: Hou Wenlong <houwenlong.hwl@...group.com>
> 
> In the user return MSR support, the cached value is always the hardware
> value of the specific MSR. Therefore, add a helper to retrieve the
> cached value, which can replace the need for RDMSR, for example, to
> allow SEV-ES guests to restore the correct host hardware value without
> using RDMSR.
> 
> Cc: stable@...r.kernel.org
> Signed-off-by: Hou Wenlong <houwenlong.hwl@...group.com>
> [sean: drop "cache" from the name, make it a one-liner, tag for stable]
> Signed-off-by: Sean Christopherson <seanjc@...gle.com>

Reviewed-by: Xiaoyao Li <xiaoyao.li@...el.com>