[PATCHv10,02/15] x86: CPUID and CR3/CR4 flags for Linear Address Masking
Commit Message
Enumerate Linear Address Masking and provide defines for CR3 and CR4
flags.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/processor-flags.h | 2 ++
arch/x86/include/uapi/asm/processor-flags.h | 6 ++++++
3 files changed, 9 insertions(+)
@@ -308,6 +308,7 @@
/* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
#define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI instructions */
#define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instructions */
+#define X86_FEATURE_LAM (12*32+26) /* Linear Address Masking */
/* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 13 */
#define X86_FEATURE_CLZERO (13*32+ 0) /* CLZERO instruction */
@@ -28,6 +28,8 @@
* On systems with SME, one bit (in a variable position!) is stolen to indicate
* that the top-level paging structure is encrypted.
*
+ * On systemms with LAM, bits 61 and 62 are used to indicate LAM mode.
+ *
* All of the remaining bits indicate the physical address of the top-level
* paging structure.
*
@@ -82,6 +82,10 @@
#define X86_CR3_PCID_BITS 12
#define X86_CR3_PCID_MASK (_AC((1UL << X86_CR3_PCID_BITS) - 1, UL))
+#define X86_CR3_LAM_U57_BIT 61 /* Activate LAM for userspace, 62:57 bits masked */
+#define X86_CR3_LAM_U57 _BITULL(X86_CR3_LAM_U57_BIT)
+#define X86_CR3_LAM_U48_BIT 62 /* Activate LAM for userspace, 62:48 bits masked */
+#define X86_CR3_LAM_U48 _BITULL(X86_CR3_LAM_U48_BIT)
#define X86_CR3_PCID_NOFLUSH_BIT 63 /* Preserve old PCID */
#define X86_CR3_PCID_NOFLUSH _BITULL(X86_CR3_PCID_NOFLUSH_BIT)
@@ -132,6 +136,8 @@
#define X86_CR4_PKE _BITUL(X86_CR4_PKE_BIT)
#define X86_CR4_CET_BIT 23 /* enable Control-flow Enforcement Technology */
#define X86_CR4_CET _BITUL(X86_CR4_CET_BIT)
+#define X86_CR4_LAM_SUP_BIT 28 /* LAM for supervisor pointers */
+#define X86_CR4_LAM_SUP _BITUL(X86_CR4_LAM_SUP_BIT)
/*
* x86-64 Task Priority Register, CR8