linux-kernel - [PATCH Part2 RFC v2 09/37] x86/traps: Define RMP violation #PF error code

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Date:   Fri, 30 Apr 2021 07:37:54 -0500
From:   Brijesh Singh <brijesh.singh@....com>
To:     x86@...nel.org, linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     tglx@...utronix.de, bp@...en8.de, jroedel@...e.de,
        thomas.lendacky@....com, pbonzini@...hat.com, mingo@...hat.com,
        dave.hansen@...el.com, rientjes@...gle.com, seanjc@...gle.com,
        peterz@...radead.org, hpa@...or.com, tony.luck@...el.com,
        Brijesh Singh <brijesh.singh@....com>
Subject: [PATCH Part2 RFC v2 09/37] x86/traps: Define RMP violation #PF error code

Bit 31 in the page fault-error bit will be set when processor encounters
an RMP violation.

While at it, use the BIT() macro.

Signed-off-by: Brijesh Singh <brijesh.singh@....com>
---
 arch/x86/include/asm/trap_pf.h | 18 +++++++++++-------
 arch/x86/mm/fault.c            |  1 +
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/trap_pf.h b/arch/x86/include/asm/trap_pf.h
index 10b1de500ab1..29f678701753 100644
--- a/arch/x86/include/asm/trap_pf.h
+++ b/arch/x86/include/asm/trap_pf.h
@@ -2,6 +2,8 @@
 #ifndef _ASM_X86_TRAP_PF_H
 #define _ASM_X86_TRAP_PF_H
 
+#include <vdso/bits.h>  /* BIT() macro */
+
 /*
  * Page fault error code bits:
  *
@@ -12,15 +14,17 @@
  *   bit 4 ==				1: fault was an instruction fetch
  *   bit 5 ==				1: protection keys block access
  *   bit 15 ==				1: SGX MMU page-fault
+ *   bit 31 ==				1: fault was an RMP violation
  */
 enum x86_pf_error_code {
-	X86_PF_PROT	=		1 << 0,
-	X86_PF_WRITE	=		1 << 1,
-	X86_PF_USER	=		1 << 2,
-	X86_PF_RSVD	=		1 << 3,
-	X86_PF_INSTR	=		1 << 4,
-	X86_PF_PK	=		1 << 5,
-	X86_PF_SGX	=		1 << 15,
+	X86_PF_PROT	=		BIT(0),
+	X86_PF_WRITE	=		BIT(1),
+	X86_PF_USER	=		BIT(2),
+	X86_PF_RSVD	=		BIT(3),
+	X86_PF_INSTR	=		BIT(4),
+	X86_PF_PK	=		BIT(5),
+	X86_PF_SGX	=		BIT(15),
+	X86_PF_RMP	=		BIT(31),
 };
 
 #endif /* _ASM_X86_TRAP_PF_H */
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index a73347e2cdfc..39d22f6870e1 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -545,6 +545,7 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad
 		 !(error_code & X86_PF_PROT) ? "not-present page" :
 		 (error_code & X86_PF_RSVD)  ? "reserved bit violation" :
 		 (error_code & X86_PF_PK)    ? "protection keys violation" :
+		 (error_code & X86_PF_RMP)   ? "rmp violation" :
 					       "permissions violation");
 
 	if (!(error_code & X86_PF_USER) && user_mode(regs)) {
-- 
2.17.1