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Message-ID: <737613ab-8b3e-1289-7ed6-0966bd43e359@intel.com>
Date:   Wed, 28 Jun 2023 16:19:11 +0800
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Subject: Re: [PATCH v1 2/6] KVM: x86: Virtualize CR4.LASS
To:     Sean Christopherson <seanjc@google.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        H Peter Anvin <hpa@zytor.com>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20230601142309.6307-1-guang.zeng@intel.com>
 <20230601142309.6307-3-guang.zeng@intel.com> <ZJsfsjwug9PcQFLA@google.com>
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From:   Zeng Guang <guang.zeng@intel.com>
In-Reply-To: <ZJsfsjwug9PcQFLA@google.com>
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On 6/28/2023 1:43 AM, Sean Christopherson wrote:
> On Thu, Jun 01, 2023, Zeng Guang wrote:
>> Virtualize CR4.LASS[bit 27] under KVM control instead of being guest-owned
>> as CR4.LASS generally set once for each vCPU at boot time and won't be
>> toggled at runtime. Besides, only if VM has LASS capability enumerated with
>> CPUID.(EAX=07H.ECX=1):EAX.LASS[bit 6], KVM allows guest software to be able
>> to set CR4.LASS.
>>
>> Updating cr4_fixed1 to set CR4.LASS bit in the emulated IA32_VMX_CR4_FIXED1
>> MSR for guests and allow guests to enable LASS in nested VMX operaion as well.
> s/operaion/operation.
Will fix in next version. Thanks.