3.16.78-rc1 review patch. If anyone has any objections, please let me know.
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From: Zhenzhong Duan zhenzhong.duan@oracle.com
commit 517c3ba00916383af6411aec99442c307c23f684 upstream.
X86_HYPER_NATIVE isn't accurate for checking if running on native platform, e.g. CONFIG_HYPERVISOR_GUEST isn't set or "nopv" is enabled.
Checking the CPU feature bit X86_FEATURE_HYPERVISOR to determine if it's running on native platform is more accurate.
This still doesn't cover the platforms on which X86_FEATURE_HYPERVISOR is unsupported, e.g. VMware, but there is nothing which can be done about this scenario.
Fixes: 8a4b06d391b0 ("x86/speculation/mds: Add sysfs reporting for MDS") Signed-off-by: Zhenzhong Duan zhenzhong.duan@oracle.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lkml.kernel.org/r/1564022349-17338-1-git-send-email-zhenzhong.duan@o... [bwh: Backported to 3.16: The old hypervisor check looked a bit different here.] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1349,12 +1349,10 @@ static ssize_t itlb_multihit_show_state(
static ssize_t mds_show_state(char *buf) { -#ifdef CONFIG_HYPERVISOR_GUEST - if (x86_hyper) { + if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) { return sprintf(buf, "%s; SMT Host state unknown\n", mds_strings[mds_mitigation]); } -#endif
if (boot_cpu_has(X86_BUG_MSBDS_ONLY)) { return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],