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@xxxxxxxxxx>
---
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: David Woodhouse <dwmw@xxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: KarimAllah Ahmed <karahmed@xxxxxxxxx>
---
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;
}
}
--
2.13.4
