[PATCH 16/37] x86/pgtable/pae: Unshare kernel PMDs when PTI is enabled

From: Joerg Roedel
Date: Mon Apr 23 2018 - 11:54:46 EST


From: Joerg Roedel <jroedel@xxxxxxx>

With PTI we need to map the per-process LDT into the kernel
address-space for each process, so we need separate kernel
PMDs per PGD.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
arch/x86/include/asm/pgtable-3level_types.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/pgtable-3level_types.h b/arch/x86/include/asm/pgtable-3level_types.h
index 6a59a6d..78038e0 100644
--- a/arch/x86/include/asm/pgtable-3level_types.h
+++ b/arch/x86/include/asm/pgtable-3level_types.h
@@ -21,9 +21,10 @@ typedef union {
#endif /* !__ASSEMBLY__ */

#ifdef CONFIG_PARAVIRT
-#define SHARED_KERNEL_PMD (pv_info.shared_kernel_pmd)
+#define SHARED_KERNEL_PMD ((!static_cpu_has(X86_FEATURE_PTI) && \
+ (pv_info.shared_kernel_pmd)))
#else
-#define SHARED_KERNEL_PMD 1
+#define SHARED_KERNEL_PMD (!static_cpu_has(X86_FEATURE_PTI))
#endif

/*
--
2.7.4