From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0CD941A682A; Thu, 13 Aug 2026 15:29:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786634951; cv=none; b=hY3e3i214q9/c9D2JM14ntw5tLXUsLCjy+yydDxjRmbxCpspFijRZlgA9FULR2c33QywA8TVO4npEysIMcNj3zokLZVFk6LsxkCWf+rF/JfltL7sVuVO0Wc84tUnuiSdtnSaZyi4JEQS86/Ye8QKaNLwamODZ3SsMde+w3qixfE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786634951; c=relaxed/simple; bh=hwSP41DeEmtt7lyKNcI/TpZqJSs8Qf3xJssO3OjtPzI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=OoknC8Rdn15W6ZULOygIC+Hb7CL8IBKuKFxMG/b59bZjfWU/4qZhIiZcBb6mCu04QLTnve5BJBUDB5VRCs8S3gntMZRznJ6+QwpxJmIcjD4yimD17qUHSGWqvSU4KYyLTWq1rERHQn+r6XHUIhn7cNhNGIwtHdI6FBV7ykHHq7g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=itBB1IFK; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="itBB1IFK" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9A52D1576; Thu, 13 Aug 2026 08:29:03 -0700 (PDT) Received: from [10.1.25.28] (e122027.cambridge.arm.com [10.1.25.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0AEDE3F632; Thu, 13 Aug 2026 08:29:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1786634947; bh=hwSP41DeEmtt7lyKNcI/TpZqJSs8Qf3xJssO3OjtPzI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=itBB1IFKjNP9DbOkr/kHIFoks2lYJmw2ANl9SZOyFtDGubOYpdT76oI7qrubQEhvS 5CjB+gB8LUXcDTjQRcQSWY6Q6ualkMYYZmfwi0DTp/zbv1DYBQRKXsuxkDEpuSoxfE QqxzU6p1Q2t+mx6kzqQs9ixwC+4AMFZV+Ve9mJkc= Message-ID: Date: Thu, 13 Aug 2026 15:38:19 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v16 21/45] KVM: arm64: CCA: Handle realm enter/exit To: "Aneesh Kumar K.V" , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: 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 References: <20260803134403.80630-1-steven.price@arm.com> <20260803134403.80630-22-steven.price@arm.com> From: Steven Price Content-Language: en-GB In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 04/08/2026 09:57, Aneesh Kumar K.V wrote: > 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(). Yes that seems like it's slightly neater. Thanks, Steve > > -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