From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4A40CCCF9F8 for ; Fri, 7 Nov 2025 23:12:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=L5g3WJg5ro6ZPgCzGJHkVpWPf3BLafiGjcPsny3z3sE=; b=UlXpCYkiKhtx8SH8VnRZUd/T8K oNEqLcBiGC4I/pkm+mUsQSHhsMB/vXoezQVZjAx7ezKdAPztaftzeexzcfyijnONJf/sIfz7hmJ2A wltkVlTdYLgR9njY9SvIpEr72q8/IqDeuS091dNvtCd7jEO9BHE9CXH8GiWYCYCDQUS/g4eIU80jI xSB1ciSb8XC1PSNGKd2/WLCgpf5YeBeCgVhmSAxs2R/ZcxT/4i3E3G+3nVKClGpqIGkG22pcdmQzp uHiwXSKaJp7ITCwgZceMRfn3t7epOvfCCzVJGuZ5wuAdEF03Vb66bKl2I3gc3VICRwOdw/0QqIHNa OMU46/9Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vHVcz-00000001Tt9-4BfW; Fri, 07 Nov 2025 23:12:22 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vHVcx-00000001TsS-3pTz for linux-arm-kernel@lists.infradead.org; Fri, 07 Nov 2025 23:12:21 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 4EA3D43967; Fri, 7 Nov 2025 23:12:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 07D1CC19422; Fri, 7 Nov 2025 23:12:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762557139; bh=B0AHPl2PuZVRK5tNUjTCgltSSw3SvWwui8ypfs0L1Bo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pR1paCW0yy1ljJ/PJey7H4gvzNzun7TU/nG39UXNM9qpH/AbmbkLBGrkhNaFJU2+m 65lf8lfc5Fb9C9ih1kF5S/R3KK0jO2WMSYsd3nTq5m3jODKkIIKG7d0FlMQ5A1PQ4I tjyINcHKBmnviErAiQdE6Tb7vQs+1R0/JnrViPlLDsnVYZ+vP6imooi9jpGbsZoQBm rr0bXyYbdokB51EoaE5Kil5+0bsWAMS4PnE/w6oNljI7vGdbDkVu2NVAgAE0ASOUJW dF8bkNVSEEfXGyhi1HZUpaYkosV1ix/N3qEGDlq/MoiQYn5/YQob4mKT1QJk7aBV6K xkI/xnTTE0WIw== Date: Fri, 7 Nov 2025 15:12:17 -0800 From: Oliver Upton To: Fuad Tabba Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, maz@kernel.org, oliver.upton@linux.dev, will@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, vladimir.murzin@arm.com Subject: Re: [PATCH v2 5/5] KVM: arm64: Define FAR_MASK for fault IPA offset Message-ID: References: <20251106144418.2847443-1-tabba@google.com> <20251106144418.2847443-6-tabba@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251106144418.2847443-6-tabba@google.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251107_151219_998398_97F825BC X-CRM114-Status: GOOD ( 21.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Nov 06, 2025 at 02:44:17PM +0000, Fuad Tabba wrote: > This 12-bit FAR mask is hard-coded as 'GENMASK(11, 0)' in several places > to reconstruct the full fault IPA. > > Define FAR_MASK for this value in the shared header and replace all > open-coded instances to improve readability. > > No functional change intended. > > Signed-off-by: Fuad Tabba > --- > arch/arm64/include/asm/kvm_arm.h | 2 ++ > arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c | 2 +- > arch/arm64/kvm/inject_fault.c | 2 +- > arch/arm64/kvm/mmu.c | 4 ++-- > 4 files changed, 6 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h > index 1da290aeedce..e995e9b3a0c4 100644 > --- a/arch/arm64/include/asm/kvm_arm.h > +++ b/arch/arm64/include/asm/kvm_arm.h > @@ -343,6 +343,8 @@ > #define PAR_TO_HPFAR(par) \ > (((par) & GENMASK_ULL(52 - 1, 12)) >> 8) > > +#define FAR_MASK GENMASK_ULL(11, 0) > + This seems really confusing to me, since FAR_MASK sounds like it represents the meaningful bits of FAR_ELx. Perhaps something like the following would better represent intent: #define FAR_TO_FIPA_OFFSET(far) ((far) & GENMASK_ULL(11, 0)) Thanks, Oliver > #define ECN(x) { ESR_ELx_EC_##x, #x } > > #define kvm_arm_exception_class \ > diff --git a/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c > index 78579b31a420..22898ed4dd6f 100644 > --- a/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c > +++ b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c > @@ -44,7 +44,7 @@ int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu) > > /* Build the full address */ > fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); > - fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0); > + fault_ipa |= kvm_vcpu_get_hfar(vcpu) & FAR_MASK; > > /* If not for GICV, move on */ > if (fault_ipa < vgic->vgic_cpu_base || > diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c > index dfcd66c65517..8ef3453696a2 100644 > --- a/arch/arm64/kvm/inject_fault.c > +++ b/arch/arm64/kvm/inject_fault.c > @@ -258,7 +258,7 @@ void kvm_inject_size_fault(struct kvm_vcpu *vcpu) > unsigned long addr, esr; > > addr = kvm_vcpu_get_fault_ipa(vcpu); > - addr |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0); > + addr |= kvm_vcpu_get_hfar(vcpu) & FAR_MASK; > > __kvm_inject_sea(vcpu, kvm_vcpu_trap_is_iabt(vcpu), addr); > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index 7cc964af8d30..21a9442f9b1e 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c > @@ -1959,7 +1959,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) > > /* Falls between the IPA range and the PARange? */ > if (fault_ipa >= BIT_ULL(VTCR_EL2_IPA(vcpu->arch.hw_mmu->vtcr))) { > - fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0); > + fault_ipa |= kvm_vcpu_get_hfar(vcpu) & FAR_MASK; > > return kvm_inject_sea(vcpu, is_iabt, fault_ipa); > } > @@ -2059,7 +2059,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) > * faulting VA. This is always 12 bits, irrespective > * of the page size. > */ > - ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0); > + ipa |= kvm_vcpu_get_hfar(vcpu) & FAR_MASK; > ret = io_mem_abort(vcpu, ipa); > goto out_unlock; > } > -- > 2.51.2.1041.gc1ab5b90ca-goog >