[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging] x86: correct default_xen_spec_ctrl calculation
commit d6239f64713df819278bf048446d3187c6ac4734 Author: Jan Beulich <jbeulich@xxxxxxxx> AuthorDate: Tue May 29 12:38:52 2018 +0200 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Tue May 29 12:38:52 2018 +0200 x86: correct default_xen_spec_ctrl calculation Even with opt_msr_sc_{pv,hvm} both false we should set up the variable as usual, to ensure proper one-time setup during boot and CPU bringup. This then also brings the code in line with the comment immediately ahead of the printk() being modified saying "irrespective of guests". Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Release-acked-by: Juergen Gross <jgross@xxxxxxxx> --- xen/arch/x86/spec_ctrl.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c index 7db6e51351..fd938c33a6 100644 --- a/xen/arch/x86/spec_ctrl.c +++ b/xen/arch/x86/spec_ctrl.c @@ -195,8 +195,6 @@ custom_param("spec-ctrl", parse_spec_ctrl); static void __init print_details(enum ind_thunk thunk, uint64_t caps) { - bool use_spec_ctrl = (boot_cpu_has(X86_FEATURE_SC_MSR_PV) || - boot_cpu_has(X86_FEATURE_SC_MSR_HVM)); unsigned int _7d0 = 0, e8b = 0, tmp; /* Collect diagnostics about available mitigations. */ @@ -228,10 +226,9 @@ static void __init print_details(enum ind_thunk thunk, uint64_t caps) thunk == THUNK_RETPOLINE ? "RETPOLINE" : thunk == THUNK_LFENCE ? "LFENCE" : thunk == THUNK_JMP ? "JMP" : "?", - !use_spec_ctrl ? "No" : - (default_xen_spec_ctrl & SPEC_CTRL_IBRS) ? "IBRS+" : "IBRS-", - !use_spec_ctrl || !boot_cpu_has(X86_FEATURE_SSBD) - ? "" : + !boot_cpu_has(X86_FEATURE_IBRSB) ? "No" : + (default_xen_spec_ctrl & SPEC_CTRL_IBRS) ? "IBRS+" : "IBRS-", + !boot_cpu_has(X86_FEATURE_SSBD) ? "" : (default_xen_spec_ctrl & SPEC_CTRL_SSBD) ? " SSBD+" : " SSBD-", opt_ibpb ? " IBPB" : ""); @@ -493,16 +490,14 @@ void __init init_speculation_mitigations(void) } if ( use_spec_ctrl ) - { - if ( ibrs ) - default_xen_spec_ctrl |= SPEC_CTRL_IBRS; - default_spec_ctrl_flags |= SCF_ist_wrmsr; - } + + if ( ibrs ) + default_xen_spec_ctrl |= SPEC_CTRL_IBRS; } /* If we have SSBD available, see whether we should use it. */ - if ( boot_cpu_has(X86_FEATURE_SSBD) && use_spec_ctrl && opt_ssbd ) + if ( boot_cpu_has(X86_FEATURE_SSBD) && opt_ssbd ) default_xen_spec_ctrl |= SPEC_CTRL_SSBD; /* -- generated by git-patchbot for /home/xen/git/xen.git#staging _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog
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