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Date:   Tue, 14 Jul 2020 16:05:46 -0700
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Subject: Re: [PATCH v2 3/4] x86: Expose SERIALIZE for supported cpuid
To:     "Zhang, Cathy" <cathy.zhang@intel.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>
CC:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org,
        pbonzini@redhat.com, vkuznets@redhat.com, wanpengli@tencent.com,
        jmattson@google.com, joro@8bytes.org, tglx@linutronix.de,
        mingo@redhat.com, bp@alien8.de,
        ricardo.neri-calderon@linux.intel.com, kyung.min.park@intel.com,
        jpoimboe@redhat.com, gregkh@linuxfoundation.org,
        ak@linux.intel.com, dave.hansen@intel.com, tony.luck@intel.com,
        ravi.v.shankar@intel.com
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On July 14, 2020 3:42:08 PM PDT, "Zhang, Cathy" <cathy=2Ezhang@intel=2Ecom>=
 wrote:
>On 7/14/2020 11:00 AM, Sean Christopherson wrote:
>> On Tue, Jul 07, 2020 at 10:16:22AM +0800, Cathy Zhang wrote:
>>> SERIALIZE instruction is supported by intel processors,
>>> like Sapphire Rapids=2E Expose it in KVM supported cpuid=2E
>> Providing at least a rough overview of the instruction, e=2Eg=2E its
>enumeration,
>> usage, fault rules, controls, etc=2E=2E=2E would be nice=2E  In isolati=
on,
>the
>> changelog isn't remotely helpful in understanding the correctness of
>the
>> patch=2E
>Thanks Sean! Add it in the next version=2E
>>
>>> Signed-off-by: Cathy Zhang <cathy=2Ezhang@intel=2Ecom>
>>> ---
>>>   arch/x86/kvm/cpuid=2Ec | 3 ++-
>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/x86/kvm/cpuid=2Ec b/arch/x86/kvm/cpuid=2Ec
>>> index 8a294f9=2E=2Ee603aeb 100644
>>> --- a/arch/x86/kvm/cpuid=2Ec
>>> +++ b/arch/x86/kvm/cpuid=2Ec
>>> @@ -341,7 +341,8 @@ void kvm_set_cpu_caps(void)
>>>   	kvm_cpu_cap_mask(CPUID_7_EDX,
>>>   		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
>>>   		F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
>>> -		F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM)
>>> +		F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM) |
>>> +		F(SERIALIZE)
>>>   	);
>>>  =20
>>>   	/* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software=2E */
>>> --=20
>>> 1=2E8=2E3=2E1
>>>

At least that one is easy: SERIALIZE is architecturally a NOP, but with ha=
rd serialization, like CPUID or IRET=2E

--=20
Sent from my Android device with K-9 Mail=2E Please excuse my brevity=2E