[PATCH 2/7] KVM: arm64: Unconditionally set IL for injected undefined exceptions

[Fuad Tabba]

inject_undef64() derives IL from the triggering trap's instruction
length (kvm_vcpu_trap_il_is32bit()), but the IL of the injected
exception is fixed by its EC, not by the triggering instruction. The
architecture mandates IL=1 for EC=0 (Unknown) unconditionally, so the
conditional is wrong. The undef-injection paths are not reached from
16-bit instructions, so there is no functional change today, but the
logic should not rely on that.

Set ESR_ELx_IL unconditionally.

Fixes: aa8eff9bfbd5 ("arm64: KVM: fault injection into a guest")
Signed-off-by: Fuad Tabba <tabba at google.com>
---
 arch/arm64/kvm/inject_fault.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
index 89982bd3345f..9dfae1bcdf99 100644
--- a/arch/arm64/kvm/inject_fault.c
+++ b/arch/arm64/kvm/inject_fault.c
@@ -170,14 +170,7 @@ void kvm_inject_sync(struct kvm_vcpu *vcpu, u64 esr)
 
 static void inject_undef64(struct kvm_vcpu *vcpu)
 {
-	u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);
-
-	/*
-	 * Build an unknown exception, depending on the instruction
-	 * set.
-	 */
-	if (kvm_vcpu_trap_il_is32bit(vcpu))
-		esr |= ESR_ELx_IL;
+	u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT) | ESR_ELx_IL;
 
 	kvm_inject_sync(vcpu, esr);
 }
-- 
2.54.0.1136.gdb2ca164c4-goog