Messages in this thread | | | Date | Wed, 8 May 2024 22:24:47 -0700 | From | Josh Poimboeuf <> | Subject | Re: [PATCH v5 3/3] x86/bugs: Add 'spectre_bhi=vmexit' cmdline option |
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On Wed, May 08, 2024 at 06:10:21PM +0300, Nikolay Borisov wrote: > > @@ -1659,19 +1662,22 @@ static void __init bhi_select_mitigation(void) > > return; > > } > > + /* Mitigate in hardware if supported */ > > if (spec_ctrl_bhi_dis()) > > return; > > if (!IS_ENABLED(CONFIG_X86_64)) > > return; > > - /* Mitigate KVM by default */ > > - setup_force_cpu_cap(X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT); > > - pr_info("Spectre BHI mitigation: SW BHB clearing on vm exit\n"); > > + if (bhi_mitigation == BHI_MITIGATION_VMEXIT_ONLY) { > > + pr_info("Spectre BHI mitigation: SW BHB clearing on vm exit only\n"); > > + setup_force_cpu_cap(X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT); > > + return; > > + } > > nit: How about setting CLEAR_BHB_LOOP_ON_VMEXIT unconditionally, then > afterwards checking if MITIGATION_VMEXIT_ONLY is set and if yes simply > return, that way you don't duplicate the setup of the VMEXIT code
I think the duplication actually makes it more readable. In both cases it puts the setting of the features together along with the corresponding pr_info().
-- Josh
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