lkml.org 
[lkml]   [2019]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.2 182/215] x86/speculation/mds: Apply more accurate check on hypervisor platform
Date
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>
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 <gregkh@linuxfoundation.org>

---
arch/x86/kernel/cpu/bugs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1226,7 +1226,7 @@ static ssize_t l1tf_show_state(char *buf

static ssize_t mds_show_state(char *buf)
{
- if (!hypervisor_is_type(X86_HYPER_NATIVE)) {
+ if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
return sprintf(buf, "%s; SMT Host state unknown\n",
mds_strings[mds_mitigation]);
}

\
 
 \ /
  Last update: 2019-07-29 22:10    [W:0.716 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site