Messages in this thread | | | Date | Thu, 31 Mar 2022 09:25:28 -0700 | From | Pawan Gupta <> | Subject | Re: [PATCH v2] x86/speculation/srbds: do not try to turn mitigation off when not supported |
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On Thu, Mar 31, 2022 at 05:25:27PM +0200, Borislav Petkov wrote: >On Thu, Mar 31, 2022 at 03:18:42PM +0200, Ricardo Cañuelo wrote: >> Just to clarify, this changes the behavior wrt the hypervisor case: >> currently it just bails out of update_srbds_msr(), with your patch it'd >> clear RNGDS_MITG_DIS from MSR_IA32_MCU_OPT_CTRL. Is that what you >> intended?
Yes, this should be fine as update_srbds_msr() would also check for X86_FEATURE_SRBDS_CTRL. If a hypervisor doesn't want a guest to write to the MSR it should not export X86_FEATURE_SRBDS_CTRL.
>Just do the simple thing I pasted earlier - no need to rewrite the whole >function for no good reason.
I was trying to address earlier comment on split logic in two functions. I am okay with keeping it as is (and just adding X86_FEATURE_SRBDS_CTRL check in update_srbds_msr()).
Thanks, Pawan
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