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 A290F389F79; Wed, 17 Dec 2025 14:29:52 +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=1765981794; cv=none; b=ihAVE+lm40y9mO3VXQTrbd3gKs7dTlV1yYWmU4uiAQUQ+b/b1Z7HFG3hGuDeS+P8poW0lb1swB7ya4clWndUeIsE65nJdX8y9UfYe0FOu8thh16AYSnWjoLcvNhz5yhUpYGwIZQM9ptaAR5kccYFvIPuHUf4NdpYou7AnrJTuS4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765981794; c=relaxed/simple; bh=P8UoqtDkSIejHJ3dZSwB+Al5ZpdAYzsvTp6EFWWH3vM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=c22ifXSKW8zav82DVUCEmZPrFhRLILfeakXcroibVufkJabOPfNkRW+dH3P0E8Ht4BsckJMT1EPzNA1Hr5n+LvZh12r/bE67c3q8oWgtwPAOfb5XndAuhiPdsrd7NktAkdx6PGkgygAcHiQdfSogqvoTZ6O1mS4CLHYvRw30et0= 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; 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 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 91910FEC; Wed, 17 Dec 2025 06:29:44 -0800 (PST) Received: from [10.57.79.105] (unknown [10.57.79.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 495223F73B; Wed, 17 Dec 2025 06:29:48 -0800 (PST) Message-ID: Date: Wed, 17 Dec 2025 14:29:46 +0000 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v12 11/46] arm64: RMI: Activate realm on first VCPU run Content-Language: en-GB To: Steven Price , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , 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 , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve References: <20251217101125.91098-1-steven.price@arm.com> <20251217101125.91098-12-steven.price@arm.com> From: Suzuki K Poulose In-Reply-To: <20251217101125.91098-12-steven.price@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 17/12/2025 10:10, Steven Price wrote: > When a VCPU migrates to another physical CPU check if this is the first > time the guest has run, and if so activate the realm. > > Before the realm can be activated it must first be created, this is a > stub in this patch and will be filled in by a later patch. > > Signed-off-by: Steven Price > --- > New patch for v12 > --- > arch/arm64/include/asm/kvm_rmi.h | 1 + > arch/arm64/kvm/arm.c | 6 +++++ > arch/arm64/kvm/rmi.c | 42 ++++++++++++++++++++++++++++++++ > 3 files changed, 49 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h > index cb7350f8a01a..e4534af06d96 100644 > --- a/arch/arm64/include/asm/kvm_rmi.h > +++ b/arch/arm64/include/asm/kvm_rmi.h > @@ -69,6 +69,7 @@ void kvm_init_rmi(void); > u32 kvm_realm_ipa_limit(void); > > int kvm_init_realm_vm(struct kvm *kvm); > +int kvm_activate_realm(struct kvm *kvm); > void kvm_destroy_realm(struct kvm *kvm); > void kvm_realm_destroy_rtts(struct kvm *kvm); > > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index 941d1bec8e77..542df37b9e82 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -951,6 +951,12 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) > return ret; > } > > + if (kvm_is_realm(vcpu->kvm)) { > + ret = kvm_activate_realm(kvm); > + if (ret) > + return ret; > + } > + > mutex_lock(&kvm->arch.config_lock); > set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags); > mutex_unlock(&kvm->arch.config_lock); > diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c > index e57e8b7eafa9..98929382c365 100644 > --- a/arch/arm64/kvm/rmi.c > +++ b/arch/arm64/kvm/rmi.c > @@ -223,6 +223,48 @@ void kvm_realm_destroy_rtts(struct kvm *kvm) > WARN_ON(realm_tear_down_rtt_range(realm, 0, (1UL << ia_bits))); > } > > +static int realm_ensure_created(struct kvm *kvm) > +{ > + /* Provided in later patch */ > + return -ENXIO; > +} > + > +int kvm_activate_realm(struct kvm *kvm) > +{ > + struct realm *realm = &kvm->arch.realm; > + int ret; > + > + if (!kvm_is_realm(kvm)) > + return -ENXIO; > + > + if (kvm_realm_state(kvm) == REALM_STATE_ACTIVE) > + return 0; > + > + guard(mutex)(&kvm->arch.config_lock); > + /* Check again with the lock held */ > + if (kvm_realm_state(kvm) == REALM_STATE_ACTIVE) > + return 0; > + > + ret = realm_ensure_created(kvm); > + if (ret) > + return ret; > + > + /* Mark state as dead in case we fail */ > + WRITE_ONCE(realm->state, REALM_STATE_DEAD); > + > + if (!irqchip_in_kernel(kvm)) { > + /* Userspace irqchip not yet supported with realms */ > + return -EOPNOTSUPP; > + } super minor nit: We could do this check before create the realm, within the config_lock'ed region. Suzuki