[PATCHv3 06/17] x86/mm: Introduce variables to store number, shift and mask of KeyIDs

Kirill A. Shutemov
2018-06-12T14:40:47Z

mktme_nr_keyids holds number of KeyIDs available for MKTME, excluding
KeyID zero which used by TME. MKTME KeyIDs start from 1.

mktme_keyid_shift holds shift of KeyID within physical address.

mktme_keyid_mask holds mask to extract KeyID from physical address.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/x86/include/asm/mktme.h | 16 ++++++++++++++++
arch/x86/kernel/cpu/intel.c | 12 ++++++++----
arch/x86/mm/Makefile | 2 ++
arch/x86/mm/mktme.c | 5 +++++
4 files changed, 31 insertions(+), 4 deletions(-)
create mode 100644 arch/x86/include/asm/mktme.h
create mode 100644 arch/x86/mm/mktme.c

diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h
new file mode 100644
index 000000000000..df31876ec48c
--- /dev/null
+++ b/arch/x86/include/asm/mktme.h
@@ -0,0 +1,16 @@
+#ifndef _ASM_X86_MKTME_H
+#define _ASM_X86_MKTME_H
+
+#include <linux/types.h>
+
+#ifdef CONFIG_X86_INTEL_MKTME
+extern phys_addr_t mktme_keyid_mask;
+extern int mktme_nr_keyids;
+extern int mktme_keyid_shift;
+#else
+#define mktme_keyid_mask ((phys_addr_t)0)
+#define mktme_nr_keyids 0
+#define mktme_keyid_shift 0
+#endif
+
+#endif
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index bf2caf9d52dd..efc9e9fc47d4 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -573,6 +573,9 @@ static void detect_tme(struct cpuinfo_x86 *c)

#ifdef CONFIG_X86_INTEL_MKTME
if (mktme_status == MKTME_ENABLED && nr_keyids) {
+ mktme_nr_keyids = nr_keyids;
+ mktme_keyid_shift = c->x86_phys_bits - keyid_bits;
+
/*
* Mask out bits claimed from KeyID from physical address mask.
*
@@ -580,10 +583,8 @@ static void detect_tme(struct cpuinfo_x86 *c)
* and number of bits claimed for KeyID is 6, bits 51:46 of
* physical address is unusable.
*/
- phys_addr_t keyid_mask;
-
- keyid_mask = GENMASK_ULL(c->x86_phys_bits - 1, c->x86_phys_bits - keyid_bits);
- physical_mask &= ~keyid_mask;
+ mktme_keyid_mask = GENMASK_ULL(c->x86_phys_bits - 1, mktme_keyid_shift);
+ physical_mask &= ~mktme_keyid_mask;
} else {
/*
* Reset __PHYSICAL_MASK.
@@ -591,6 +592,9 @@ static void detect_tme(struct cpuinfo_x86 *c)
* between CPUs.
*/
physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
+ mktme_keyid_mask = 0;
+ mktme_keyid_shift = 0;
+ mktme_nr_keyids = 0;
}
#endif

diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 4b101dd6e52f..4ebee899c363 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -53,3 +53,5 @@ obj-$(CONFIG_PAGE_TABLE_ISOLATION) += pti.o
obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt.o
obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_identity.o
obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_boot.o
+
+obj-$(CONFIG_X86_INTEL_MKTME) += mktme.o
diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
new file mode 100644
index 000000000000..467f1b26c737
--- /dev/null
+++ b/arch/x86/mm/mktme.c
@@ -0,0 +1,5 @@
+#include <asm/mktme.h>
+
+phys_addr_t mktme_keyid_mask;
+int mktme_nr_keyids;
+int mktme_keyid_shift;
--
2.17.1