On 2/12/19 14:50, Jan Beulich wrote: >>>> On 08.02.19 at 14:44, <[email protected]> wrote: >> --- /dev/null >> +++ b/xen/include/asm-x86/nospec.h >> @@ -0,0 +1,39 @@ >> +/* SPDX-License-Identifier: GPL-2.0 */ >> +/* Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved. >> */ >> + >> +#ifndef _ASM_X86_NOSPEC_H >> +#define _ASM_X86_NOSPEC_H >> + >> +#include <asm/alternative.h> >> +#include <asm/system.h> >> + >> +/* Allow to insert a read memory barrier into conditionals */ >> +static always_inline bool arch_barrier_nospec_true(void) > Now that this is x86-specific (and not used by common code), > I don't think the arch_ prefix is warranted anymore. I will drop the prefix. >> +{ >> +#if defined(CONFIG_HVM) > Here and below I'd prefer if you used the shorter #ifdef. I will use the short version. > >> + alternative("", "lfence", X86_FEATURE_SC_L1TF_VULN); >> +#endif >> + return true; >> +} >> + >> +/* Allow to protect evaluation of conditionaasl with respect to speculation >> */ >> +#if defined(CONFIG_HVM) >> +#define evaluate_nospec(condition) \ >> + ((condition) ? arch_barrier_nospec_true() : !arch_barrier_nospec_true()) >> +#else >> +#define evaluate_nospec(condition) (condition) >> +#endif >> + >> +/* Allow to block speculative execution in generic code */ >> +#define block_speculation() (void)arch_barrier_nospec_true() > I'm pretty sure that I did point out before that this lacks an > outer pair of parentheses.
You did. I will add them. Best, Norbert > > Jan > > Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich Ust-ID: DE 289 237 879 Eingetragen am Amtsgericht Charlottenburg HRB 149173 B _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
