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 225D0C5518F for ; Tue, 4 Aug 2026 08:57:26 +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:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From: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=xxS0NRBY3i0kZcuHxe0V5BgtVYZZ3/0KR07GPgwzac4=; b=F0EkyWVWyOnOCPqzFZGFc7Jixl olrCQD1/TDHcLvtyDOHBF+YhpI/hJ2BFeZvSlEhZ1b479W9b+bUoEnIfs/HSjjWxzCPt3QR2tHrVx aHJljZX971tnAhhkdlwKlBB6HAtkOpp2X2nfO4oGYBFc5GZT+92J8BIePIRxEcepzKD+lus9FVxh/ QfAVV8lx6WuWTzwtrWxqpCzfS/2LQ1JBm5yW/7G4IW6vCaJPO1XHJISENykef3X5/JwVq7+uLUbBI SI+W2QWVgeCp2hFKJ1L2hUgxMKMq5YIdz++s/mwkkqs/Afegcy1JmOjx4KFVT5Gu8oW8FZTbSm2Ku 6Mp7dTmg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wrAxX-00000001OsO-0nPc; Tue, 04 Aug 2026 08:57:15 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wrAxW-00000001Os9-0GAh for linux-arm-kernel@lists.infradead.org; Tue, 04 Aug 2026 08:57:14 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 09203600AA; Tue, 4 Aug 2026 08:57:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28E3A1F000E9; Tue, 4 Aug 2026 08:57:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785833832; bh=xxS0NRBY3i0kZcuHxe0V5BgtVYZZ3/0KR07GPgwzac4=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=UT90DsPzrSuia1XzFFet3nOueTooswWOFwwvIVVUp4i31U91QcZdNkPS7wDN44WfZ 5SW8BtiDJsI6Fx9pak/IUmX5Z2J+CsBdP8wwjY3f2mQUM4eQIABFyJaXxGJhayR1gn U5R+0MEmOP50TZcTUR7p1eCgQVGCvP9a8smRHHuChY1zUBlFlrNOJSODIP4Z9/TPfi uBn3/pDxKsMyP6756Kk1ACB4f53ti49Pq6U7ezDbTVRR4O1TOTd6/BFPY6zByPR6tj IFWmH0hMFRtARMPxU/r8zriH6wy2JEQQcyViZK2NO2uukW7vthHJI/O6clzH5elLoU 7Nyp9EMGnWMEA== X-Mailer: emacs 30.2 (via feedmail 11-beta-1 I) From: Aneesh Kumar K.V To: Steven Price , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , Emi Kisanuki , Vishal Annapurve , WeiLin.Chang@arm.com, Lorenzo Pieralisi Subject: Re: [PATCH v16 21/45] KVM: arm64: CCA: Handle realm enter/exit In-Reply-To: <20260803134403.80630-22-steven.price@arm.com> References: <20260803134403.80630-1-steven.price@arm.com> <20260803134403.80630-22-steven.price@arm.com> Date: Tue, 04 Aug 2026 14:27:03 +0530 Message-ID: MIME-Version: 1.0 Content-Type: text/plain 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 Steven Price writes: > + switch (rec->run->exit.exit_reason) { > + case RMI_EXIT_SYNC: > + /* > + * HPFAR_EL2_NS is hijacked to indicate a valid HPFAR value, > + * see __get_fault_info() > + */ > + vcpu->arch.fault.hpfar_el2 = rec->run->exit.hpfar | HPFAR_EL2_NS; > + rec_exit_sync(vcpu); > + return ARM_EXCEPTION_TRAP; > + case RMI_EXIT_IRQ: > + case RMI_EXIT_FIQ: > + return ARM_EXCEPTION_IRQ; > + case RMI_EXIT_SERROR: > + return ARM_EXCEPTION_EL1_SERROR; > + case RMI_EXIT_PSCI: > + rec_exit_hvc(vcpu); > + kvm_make_request(KVM_REQ_RMI, vcpu); > + return ARM_EXCEPTION_TRAP; > + case RMI_EXIT_RIPAS_CHANGE: > + rec_exit_hvc(vcpu); > + return ARM_EXCEPTION_TRAP; > + } Should we handle RMI_EXIT_RIPAS_CHANGE differently? Currently, the call path is: kvm_rec_exit() -> RMI_EXIT_RIPAS_CHANGE -> handle_hvc() -> kvm_rec_handle_hvc() -> kvm_prepare_memory_fault_exit() Could we instead treat RMI_EXIT_RIPAS_CHANGE as a special case and avoid redirecting it through handle_hvc()? The completion part of the RIPAS change could still be handled by kvm_rec_handle_request(). -bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret) +static int rec_exit_ripas_change(struct kvm_vcpu *vcpu) { - struct realm_rec *rec; + struct realm_rec *rec = &vcpu->arch.rec; struct realm *realm; unsigned long base; unsigned long ripas; unsigned long top; - if (!vcpu_is_rec(vcpu)) - return false; - - rec = &vcpu->arch.rec; - if (rec->run->exit.exit_reason != RMI_EXIT_RIPAS_CHANGE) - return false; - realm = &vcpu->kvm->arch.realm; base = rec->run->exit.ripas_base; top = rec->run->exit.ripas_top; @@ -89,8 +83,7 @@ bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret) base, top, ripas); /* Set RMI_REJECT bit */ rec->run->enter.flags = REC_ENTER_FLAG_RIPAS_RESPONSE; - *ret = -EINVAL; - return true; + return -EINVAL; } /* Exit to VMM, the actual RIPAS change is done on next entry */ @@ -102,8 +95,7 @@ bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret) * KVM_EXIT_MEMORY_FAULT requires a return code of -EFAULT, see the * API documentation */ - *ret = -EFAULT; - return true; + return -EFAULT; } int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret) @@ -169,8 +161,7 @@ int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret) kvm_make_request(KVM_REQ_RMI, vcpu); return ARM_EXCEPTION_TRAP; case RMI_EXIT_RIPAS_CHANGE: - rec_exit_hvc(vcpu); - return ARM_EXCEPTION_TRAP; + return rec_exit_ripas_change(vcpu); } return rec_exit_fatal(vcpu, "Unsupported Realm exit reason", -aneesh