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[118.163.61.247]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-b5236338fcasm1574671a12.35.2025.09.07.23.46.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 07 Sep 2025 23:46:12 -0700 (PDT) From: Wei-Lin Chang To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Cc: Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Wei-Lin Chang , Will Deacon Subject: [PATCH v2] KVM: arm64: Remove stage 2 read fault check Date: Mon, 8 Sep 2025 14:48:06 +0800 Message-ID: <20250908064806.4093081-1-r09922117@csie.ntu.edu.tw> X-Mailer: git-send-email 2.50.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Gm-Spam: 0 X-Gm-Phishy: 0 Content-Type: text/plain; charset="utf-8" In the non-NV case, read permission is always granted when mapping stage-2, so checking for it doesn't bring much. On the other hand, shadow stage-2 for NV guests could potentially have non-readable mappings when we align the permissions with those that L1 set for L2, we shouldn't be checking for read faults in this case either. So just remove this check. Suggested-by: Oliver Upton Suggested-by: Marc Zyngier Signed-off-by: Wei-Lin Chang --- Changes in v2, thanks to those listed in the Suggested-by tags: - remove the read fault check instead of skipping it for NV - Link to v1: https://lore.kernel.org/kvmarm/20250822031853.2007437-1-r09= 922117@csie.ntu.edu.tw/ --- arch/arm64/kvm/mmu.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 1c78864767c5c..fb239cd9f7a67 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1508,11 +1508,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phy= s_addr_t fault_ipa, exec_fault =3D kvm_vcpu_trap_is_exec_fault(vcpu); VM_BUG_ON(write_fault && exec_fault); =20 - if (fault_is_perm && !write_fault && !exec_fault) { - kvm_err("Unexpected L2 read permission error\n"); - return -EFAULT; - } - if (!is_protected_kvm_enabled()) memcache =3D &vcpu->arch.mmu_page_cache; else --=20 2.50.1