XSS MSR support mandatory or optional
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Yoshinoya
Hello: I have a question about cpu feature: IA32_XSS feature support is a must requirment, or optional. Where to config it on or off. Thanks |
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Junjie Mao
Hi Yoshinoya,
ACRN assumes the presence of XSAVE supervisor state components (which includes the presence of MSR IA32_XSS). That holds on most of recent processor models.
May I know if you see that feature being absent on any processor, and if so, what’s the model of it?
--- Best Regards Junjie Mao
From: acrn-dev@...
<acrn-dev@...> On Behalf Of
Yoshinoya
Sent: Wednesday, October 19, 2022 4:46 PM To: acrn-dev@... Subject: [acrn-dev] XSS MSR support mandatory or optional
Hello: I have a question about cpu feature: IA32_XSS feature support is a must requirment, or optional.
Where to config it on or off.
Thanks |
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Yoshinoya
Hi, It seems IA32 XSS feature was introduced into KVM kernel in 2018/2019. For CPU produced in 2015, maybe it does not support this feature. Maybe, board inspector/config tool could define some config items to determine use XSS feature or not. If then, maybe acrn could adapt to more broad platforms. Thanks At 2022-10-20 08:24:27, "Junjie Mao" <junjie.mao@...> wrote:
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Junjie Mao
Since ACRN started in 2018, we have not validated running ACRN on any older processor models.
What you suggested is one way to fix it. Alternatively, for features reported by CPUID (such as XSS) the hypervisor can detect it presence and behave accordingly as well, which should be much simpler.
You can refer to hypervisor/arch/x86/cpu_caps.c for how the hypervisor is collecting CPU capabilities using the CPUID instruction. Feel free to modify for your case, and it is always welcomed if you can send out your patches here and we can work together to include that in ACRN upstream.
--- Best Regards Junjie Mao
From: acrn-dev@...
<acrn-dev@...> On Behalf Of
Yoshinoya
Sent: Thursday, October 20, 2022 11:00 AM To: acrn-dev@... Subject: Re: [acrn-dev] XSS MSR support mandatory or optional
Hi, It seems IA32 XSS feature was introduced into KVM kernel in 2018/2019.
For CPU produced in 2015, maybe it does not support this feature.
Maybe, board inspector/config tool could define some config items to determine use XSS feature or not. If then, maybe acrn could adapt to more broad platforms.
Thanks
At 2022-10-20 08:24:27, "Junjie Mao" <junjie.mao@...> wrote:
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