From: Zhenzhong Duan Date: Thu, 25 Jul 2019 02:39:09 +0000 (+0800) Subject: x86/speculation/mds: Apply more accurate check on hypervisor platform X-Git-Tag: v4.4.187~17 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cef888755a349443079b5538e6a74b88b3264c55;p=thirdparty%2Fkernel%2Fstable.git x86/speculation/mds: Apply more accurate check on hypervisor platform 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 Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1564022349-17338-1-git-send-email-zhenzhong.duan@oracle.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 310e279be0d87..ab2df0f9ac455 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1094,7 +1094,7 @@ static void __init l1tf_select_mitigation(void) 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]); }