lkml.org 
[lkml]   [2018]   [Jun]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:x86/pti] x86/bugs: Switch the selection of mitigation from CPU vendor to CPU features
Commit-ID:  108fab4b5c8f12064ef86e02cb0459992affb30f
Gitweb: https://git.kernel.org/tip/108fab4b5c8f12064ef86e02cb0459992affb30f
Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
AuthorDate: Fri, 1 Jun 2018 10:59:21 -0400
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 6 Jun 2018 14:13:17 +0200

x86/bugs: Switch the selection of mitigation from CPU vendor to CPU features

Both AMD and Intel can have SPEC_CTRL_MSR for SSBD.

However AMD also has two more other ways of doing it - which
are !SPEC_CTRL MSR ways.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: kvm@vger.kernel.org
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: andrew.cooper3@citrix.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180601145921.9500-4-konrad.wilk@oracle.com

---
arch/x86/kernel/cpu/bugs.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 6bea81855cdd..cd0fda1fff6d 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -532,17 +532,12 @@ static enum ssb_mitigation __init __ssb_select_mitigation(void)
* Intel uses the SPEC CTRL MSR Bit(2) for this, while AMD may
* use a completely different MSR and bit dependent on family.
*/
- switch (boot_cpu_data.x86_vendor) {
- case X86_VENDOR_INTEL:
- case X86_VENDOR_AMD:
- if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) {
- x86_amd_ssb_disable();
- break;
- }
+ if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
+ x86_amd_ssb_disable();
+ else {
x86_spec_ctrl_base |= SPEC_CTRL_SSBD;
x86_spec_ctrl_mask |= SPEC_CTRL_SSBD;
wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
- break;
}
}

\
 
 \ /
  Last update: 2018-06-06 14:18    [W:0.106 / U:2.792 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site