EPT exit qualification bit 6 is used when mode-based execute control
is enabled, and reflects user executable addresses. Rework name to
reflect the intention and add to EPT_VIOLATION_PROT_MASK, which allows
simplifying the return evaluation in
tdx_is_sept_violation_unexpected_pending a pinch.
Rework handling in __vmx_handle_ept_violation to unconditionally clear
EPT_VIOLATION_PROT_USER_EXEC until MBEC is implemented, as suggested by
Sean [1].
Note: Intel SDM Table 29-7 defines bit 6 as:
If the “mode-based execute control” VM-execution control is 0, the
value of this bit is undefined. If that control is 1, this bit is the
logical-AND of bit 10 in the EPT paging-structure entries used to
translate the guest-physical address of the access causing the EPT
violation. In this case, it indicates whether the guest-physical
address was executable for user-mode linear addresses.
[1] https://lore.kernel.org/all/aCJDzU1p_SFNRIJd@google.com/
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jon Kohler <jon@nutanix.com>
---
arch/x86/include/asm/vmx.h | 5 +++--
arch/x86/kvm/vmx/common.h | 9 +++++++--
arch/x86/kvm/vmx/tdx.c | 2 +-
3 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index c85c50019523..de3abec84fe5 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -596,10 +596,11 @@ enum vm_entry_failure_code {
#define EPT_VIOLATION_PROT_READ BIT(3)
#define EPT_VIOLATION_PROT_WRITE BIT(4)
#define EPT_VIOLATION_PROT_EXEC BIT(5)
-#define EPT_VIOLATION_EXEC_FOR_RING3_LIN BIT(6)
+#define EPT_VIOLATION_PROT_USER_EXEC BIT(6)
#define EPT_VIOLATION_PROT_MASK (EPT_VIOLATION_PROT_READ | \
EPT_VIOLATION_PROT_WRITE | \
- EPT_VIOLATION_PROT_EXEC)
+ EPT_VIOLATION_PROT_EXEC | \
+ EPT_VIOLATION_PROT_USER_EXEC)
#define EPT_VIOLATION_GVA_IS_VALID BIT(7)
#define EPT_VIOLATION_GVA_TRANSLATED BIT(8)
diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
index 412d0829d7a2..adf925500b9e 100644
--- a/arch/x86/kvm/vmx/common.h
+++ b/arch/x86/kvm/vmx/common.h
@@ -94,8 +94,13 @@ static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
/* Is it a fetch fault? */
error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
? PFERR_FETCH_MASK : 0;
- /* ept page table entry is present? */
- error_code |= (exit_qualification & EPT_VIOLATION_PROT_MASK)
+ /*
+ * ept page table entry is present?
+ * note: unconditionally clear USER_EXEC until mode-based
+ * execute control is implemented
+ */
+ error_code |= (exit_qualification &
+ (EPT_VIOLATION_PROT_MASK & ~EPT_VIOLATION_PROT_USER_EXEC))
? PFERR_PRESENT_MASK : 0;
if (exit_qualification & EPT_VIOLATION_GVA_IS_VALID)
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 0a49c863c811..61185c30a40e 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1922,7 +1922,7 @@ static inline bool tdx_is_sept_violation_unexpected_pending(struct kvm_vcpu *vcp
if (eeq_type != TDX_EXT_EXIT_QUAL_TYPE_PENDING_EPT_VIOLATION)
return false;
- return !(eq & EPT_VIOLATION_PROT_MASK) && !(eq & EPT_VIOLATION_EXEC_FOR_RING3_LIN);
+ return !(eq & EPT_VIOLATION_PROT_MASK);
}
static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu)
--
2.43.0