[PATCH v2 1/5] kvm: x86: mmu: Use symbolic constants for EPT Violation Exit Qualifications

[Junaid Shahid <junaids@google.com>]

This change adds some symbolic constants for VM Exit Qualifications
related to EPT Violations and updates handle_ept_violation() to use
these constants instead of hard-coded numbers.

Signed-off-by: Junaid Shahid <junaids@google.com>
---
 arch/x86/include/asm/vmx.h | 16 ++++++++++++++++
 arch/x86/kvm/vmx.c         | 22 ++++++++++++++--------
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index a002b07..60991fb 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -465,6 +465,22 @@ struct vmx_msr_entry {
 #define ENTRY_FAIL_VMCS_LINK_PTR	4
 
 /*
+ * Exit Qualifications for EPT Violations
+ */
+#define EPT_VIOLATION_READ_BIT		0
+#define EPT_VIOLATION_WRITE_BIT		1
+#define EPT_VIOLATION_INSTR_BIT		2
+#define EPT_VIOLATION_READABLE_BIT	3
+#define EPT_VIOLATION_WRITABLE_BIT	4
+#define EPT_VIOLATION_EXECUTABLE_BIT	5
+#define EPT_VIOLATION_READ		(1 << EPT_VIOLATION_READ_BIT)
+#define EPT_VIOLATION_WRITE		(1 << EPT_VIOLATION_WRITE_BIT)
+#define EPT_VIOLATION_INSTR		(1 << EPT_VIOLATION_INSTR_BIT)
+#define EPT_VIOLATION_READABLE		(1 << EPT_VIOLATION_READABLE_BIT)
+#define EPT_VIOLATION_WRITABLE		(1 << EPT_VIOLATION_WRITABLE_BIT)
+#define EPT_VIOLATION_EXECUTABLE	(1 << EPT_VIOLATION_EXECUTABLE_BIT)
+
+/*
  * VM-instruction error numbers
  */
 enum vm_instruction_error_number {
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cf1b16d..88e3b02 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6170,14 +6170,20 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
 	gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
 	trace_kvm_page_fault(gpa, exit_qualification);
 
-	/* it is a read fault? */
-	error_code = (exit_qualification << 2) & PFERR_USER_MASK;
-	/* it is a write fault? */
-	error_code |= exit_qualification & PFERR_WRITE_MASK;
-	/* It is a fetch fault? */
-	error_code |= (exit_qualification << 2) & PFERR_FETCH_MASK;
-	/* ept page table is present? */
-	error_code |= (exit_qualification & 0x38) != 0;
+	/* Is it a read fault? */
+	error_code = ((exit_qualification >> EPT_VIOLATION_READ_BIT) & 1)
+		     << PFERR_USER_BIT;
+	/* Is it a write fault? */
+	error_code |= ((exit_qualification >> EPT_VIOLATION_WRITE_BIT) & 1)
+		      << PFERR_WRITE_BIT;
+	/* Is it a fetch fault? */
+	error_code |= ((exit_qualification >> EPT_VIOLATION_INSTR_BIT) & 1)
+		      << PFERR_FETCH_BIT;
+	/* ept page table entry is present? */
+	error_code |= (((exit_qualification >> EPT_VIOLATION_READABLE_BIT) |
+			(exit_qualification >> EPT_VIOLATION_WRITABLE_BIT) |
+			(exit_qualification >> EPT_VIOLATION_EXECUTABLE_BIT))
+		       & 1) << PFERR_PRESENT_BIT;
 
 	vcpu->arch.exit_qualification = exit_qualification;
 
-- 
2.8.0.rc3.226.g39d4020