commit 91df9fdf51492aec9fed6b4cbd33160886740f47 upstream
Updating microcode is less error prone when caches have been flushed and depending on what exactly the microcode is updating. For example, some of the issues around certain Broadwell parts can be addressed by doing a full cache flush.
[ Borislav: Massage it and use native_wbinvd() in both cases. ]
Signed-off-by: Ashok Raj ashok.raj@intel.com Signed-off-by: Borislav Petkov bp@suse.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Tested-by: Tom Lendacky thomas.lendacky@amd.com Tested-by: Ashok Raj ashok.raj@intel.com Cc: Arjan Van De Ven arjan.van.de.ven@intel.com Cc: Tom Lendacky thomas.lendacky@amd.com Cc: Asit K Mallick asit.k.mallick@intel.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1519352533-15992-3-git-send-email-ashok.raj@intel.c... Link: https://lkml.kernel.org/r/20180228102846.13447-4-bp@alien8.de --- arch/x86/kernel/cpu/microcode/intel.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index 87bd6dc..e2864bc 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -600,6 +600,12 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early) return UCODE_OK; }
+ /* + * Writeback and invalidate caches before updating microcode to avoid + * internal issues depending on what the microcode is updating. + */ + native_wbinvd(); + /* write microcode via MSR 0x79 */ native_wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
@@ -816,6 +822,12 @@ static enum ucode_state apply_microcode_intel(int cpu) return UCODE_OK; }
+ /* + * Writeback and invalidate caches before updating microcode to avoid + * internal issues depending on what the microcode is updating. + */ + native_wbinvd(); + /* write microcode via MSR 0x79 */ wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);