linux-kernel - [RFC PATCH 02/16] KVM: arm64: Get iabt status on-demand

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Message-ID: <20250821210042.3451147-3-seanjc@google.com>
Date: Thu, 21 Aug 2025 14:00:28 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>
Cc: linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev, 
	linux-kernel@...r.kernel.org, Sean Christopherson <seanjc@...gle.com>, 
	James Houghton <jthoughton@...gle.com>
Subject: [RFC PATCH 02/16] KVM: arm64: Get iabt status on-demand

Query if an abort was due to instruction execution only when necessary
in anticipation of factoring out the SRCU-protected portion of abort
handling to a separate helper.  The happy path doesn't need to check for
IAB, and eliminating the local variable will avoid having to pass a
large pile of booleans to the inner helper.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/arm64/kvm/mmu.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index dc3aa58e2ea5..1e3ac283c519 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1830,7 +1830,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 	phys_addr_t ipa; /* Always the IPA in the L1 guest phys space */
 	struct kvm_memory_slot *memslot;
 	unsigned long hva;
-	bool is_iabt, write_fault, writable;
+	bool write_fault, writable;
 	gfn_t gfn;
 	int ret, idx;
 
@@ -1856,8 +1856,6 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 	if (KVM_BUG_ON(ipa == INVALID_GPA, vcpu->kvm))
 		return -EFAULT;
 
-	is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
-
 	if (esr_fsc_is_translation_fault(esr)) {
 		/* Beyond sanitised PARange (which is the IPA limit) */
 		if (fault_ipa >= BIT_ULL(get_kvm_ipa_limit())) {
@@ -1869,7 +1867,8 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 		if (fault_ipa >= BIT_ULL(VTCR_EL2_IPA(vcpu->arch.hw_mmu->vtcr))) {
 			fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
 
-			return kvm_inject_sea(vcpu, is_iabt, fault_ipa);
+			return kvm_inject_sea(vcpu, kvm_vcpu_trap_is_iabt(vcpu),
+					      fault_ipa);
 		}
 	}
 
@@ -1931,7 +1930,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 		 * anything about this (there's no syndrome for a start), so
 		 * re-inject the abort back into the guest.
 		 */
-		if (is_iabt) {
+		if (kvm_vcpu_trap_is_iabt(vcpu)) {
 			ret = -ENOEXEC;
 			goto out;
 		}
-- 
2.51.0.261.g7ce5a0a67e-goog