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Date:   Fri,  2 Jun 2023 17:01:46 +0000
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Subject: [PATCH 2/3] KVM: arm64: Clear possible conflict aborts
From:   Colton Lewis <coltonlewis@google.com>
To:     kvm@vger.kernel.org
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
        Oliver Upton <oliver.upton@linux.dev>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Zenghui Yu <yuzenghui@huawei.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kvmarm@lists.linux.dev, Colton Lewis <coltonlewis@google.com>
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Clear possible conflict aborts by TLB invalidation targeted to the
address that caused the abort.

Making use of FEAT_BBM Level 2 creates the possibility of a conflict
abort when translating addresses, where multiple entries exist in the
TLB for a single input address.

Signed-off-by: Colton Lewis <coltonlewis@google.com>
---
 arch/arm64/include/asm/esr.h | 1 +
 arch/arm64/kvm/mmu.c         | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 8487aec9b6587..41336cfa19ff3 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -123,6 +123,7 @@
 #define ESR_ELx_FSC_SECC_TTW1	(0x1d)
 #define ESR_ELx_FSC_SECC_TTW2	(0x1e)
 #define ESR_ELx_FSC_SECC_TTW3	(0x1f)
+#define ESR_ELx_FSC_CONFLICT	(0x30)

 /* ISS field definitions for Data Aborts */
 #define ESR_ELx_ISV_SHIFT	(24)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 7a68398517c95..96b950f20c8d0 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1591,6 +1591,12 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 		return 1;
 	}

+	if (fault_status == ESR_ELx_FSC_CONFLICT) {
+		/* We could be at any level. 0 covers all levels. */
+		__kvm_tlb_flush_vmid_ipa(vcpu->arch.hw_mmu, fault_ipa, 0);
+		return 1;
+	}
+
 	trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu),
 			      kvm_vcpu_get_hfar(vcpu), fault_ipa);

--
2.41.0.rc0.172.g3f132b7071-goog