[PATCH v16 24/38] x86/msr: Add variable MTRR base/mask and x2apic ID registers

Ross Philipson <[email protected]> Fri, 15 May 2026 14:13:56 -0700
Newsgroups org.kernel.vger.linux-efi,dev.linux.lists.iommu,org.infradead.lists.kexec,org.kernel.vger.linux-crypto,org.kernel.vger.linux-doc,org.kernel.vger.linux-integrity,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
Add the MSR values required by Secure Launch to locate particular CPU cores
during application processor (AP) startup, and restore the MTRR state after
an Intel TXT launch.

Signed-off-by: Ross Philipson <[email protected]>
---
 arch/x86/include/asm/msr-index.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 6673601246b3..2a95e3389622 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -408,6 +408,9 @@
 #define MSR_IA32_RTIT_OUTPUT_BASE	0x00000560
 #define MSR_IA32_RTIT_OUTPUT_MASK	0x00000561
 
+#define MSR_MTRRphysBase0		0x00000200
+#define MSR_MTRRphysMask0		0x00000201
+
 #define MSR_MTRRfix64K_00000		0x00000250
 #define MSR_MTRRfix16K_80000		0x00000258
 #define MSR_MTRRfix16K_A0000		0x00000259
@@ -960,6 +963,8 @@
 #define MSR_IA32_APICBASE_ENABLE	(1<<11)
 #define MSR_IA32_APICBASE_BASE		(0xfffff<<12)
 
+#define MSR_IA32_X2APIC_APICID		0x00000802
+
 #define MSR_IA32_UCODE_WRITE		0x00000079
 
 #define MSR_IA32_MCU_ENUMERATION	0x0000007b
-- 
2.47.3