From nobody Wed Dec 17 16:11:44 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6AA1634C13B; Wed, 17 Dec 2025 10:13:00 +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=1765966381; cv=none; b=l9/t98vRBUC/iRRjirH7MNwQl0Ww1FpyxSNM3mMmFuol6pGrKVR87+/MXOtTxg8wGC4Jb5LxGonyLafPRTRH8k8xkab4ho4f45fvZT8w3Ey5SOsKavxyGYrzIBcgyAF16XeqrDOB/fvpPvBBm3Q4thmSR0x2OZ11LC95M5jiUGM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765966381; c=relaxed/simple; bh=Yu4dOpktE3klQ8F9T/Di5++S4gNK89odJ0l8YersjE8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CVmgEtqylkdHt0SrV62WVH7kpNuu/SbpW+bAMvgAQkDTQ6sfzNUHHafmNUvMErjV3ErMbTVsdCEU7dgXSyvZm1U+fD3XciKW9xP/9iVzRXQdjzwcERXFyULUQigByu+mhpTRuz5Bp3Jda2PljLfDjVVxOeL2wXHgebusvs2Y0Rg= 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 E4C911517; Wed, 17 Dec 2025 02:12:52 -0800 (PST) Received: from e122027.arm.com (unknown [10.57.45.201]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0F4F43F73B; Wed, 17 Dec 2025 02:12:54 -0800 (PST) From: Steven Price To: 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 , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve Subject: [PATCH v12 15/46] KVM: arm64: Support timers in realm RECs Date: Wed, 17 Dec 2025 10:10:52 +0000 Message-ID: <20251217101125.91098-16-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251217101125.91098-1-steven.price@arm.com> References: <20251217101125.91098-1-steven.price@arm.com> 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 Content-Type: text/plain; charset="utf-8" The RMM keeps track of the timer while the realm REC is running, but on exit to the normal world KVM is responsible for handling the timers. A later patch adds the support for propagating the timer values from the exit data structure and calling kvm_realm_timers_update(). Signed-off-by: Steven Price --- Changes since v11: * Drop the kvm_is_realm() check from timer_set_offset(). We already ensure that the offset is 0 when calling the function. Changes since v10: * KVM_CAP_COUNTER_OFFSET is now already hidden by a previous patch. Changes since v9: * No need to move the call to kvm_timer_unblocking() in kvm_timer_vcpu_load(). Changes since v7: * Hide KVM_CAP_COUNTER_OFFSET for realm guests. --- arch/arm64/kvm/arch_timer.c | 37 ++++++++++++++++++++++++++++++++++-- include/kvm/arm_arch_timer.h | 2 ++ 2 files changed, 37 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 99a07972068d..99308bde2a05 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -453,6 +453,21 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu= , bool new_level, timer_ctx); } =20 +void kvm_realm_timers_update(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *arch_timer =3D &vcpu->arch.timer_cpu; + int i; + + for (i =3D 0; i < NR_KVM_EL0_TIMERS; i++) { + struct arch_timer_context *timer =3D &arch_timer->timers[i]; + bool status =3D timer_get_ctl(timer) & ARCH_TIMER_CTRL_IT_STAT; + bool level =3D kvm_timer_irq_can_fire(timer) && status; + + if (level !=3D timer->irq.level) + kvm_timer_update_irq(vcpu, level, timer); + } +} + /* Only called for a fully emulated timer */ static void timer_emulate(struct arch_timer_context *ctx) { @@ -1056,7 +1071,9 @@ static void timer_context_init(struct kvm_vcpu *vcpu,= int timerid) =20 ctxt->timer_id =3D timerid; =20 - if (timerid =3D=3D TIMER_VTIMER) + if (kvm_is_realm(vcpu->kvm)) + ctxt->offset.vm_offset =3D NULL; + else if (timerid =3D=3D TIMER_VTIMER) ctxt->offset.vm_offset =3D &kvm->arch.timer_data.voffset; else ctxt->offset.vm_offset =3D &kvm->arch.timer_data.poffset; @@ -1078,13 +1095,19 @@ static void timer_context_init(struct kvm_vcpu *vcp= u, int timerid) void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) { struct arch_timer_cpu *timer =3D vcpu_timer(vcpu); + u64 cntvoff; =20 for (int i =3D 0; i < NR_KVM_TIMERS; i++) timer_context_init(vcpu, i); =20 + if (kvm_is_realm(vcpu->kvm)) + cntvoff =3D 0; + else + cntvoff =3D kvm_phys_timer_read(); + /* Synchronize offsets across timers of a VM if not already provided */ if (!test_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET, &vcpu->kvm->arch.flags)) { - timer_set_offset(vcpu_vtimer(vcpu), kvm_phys_timer_read()); + timer_set_offset(vcpu_vtimer(vcpu), cntvoff); timer_set_offset(vcpu_ptimer(vcpu), 0); } =20 @@ -1556,6 +1579,13 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu) return -EINVAL; } =20 + /* + * We don't use mapped IRQs for Realms because the RMI doesn't allow + * us setting the LR.HW bit in the VGIC. + */ + if (vcpu_is_rec(vcpu)) + return 0; + get_timer_map(vcpu, &map); =20 ret =3D kvm_vgic_map_phys_irq(vcpu, @@ -1687,6 +1717,9 @@ int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm, if (offset->reserved) return -EINVAL; =20 + if (kvm_is_realm(kvm)) + return -EINVAL; + mutex_lock(&kvm->lock); =20 if (!kvm_trylock_all_vcpus(kvm)) { diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index 7310841f4512..bab0daafc6b1 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -111,6 +111,8 @@ int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struc= t kvm_device_attr *attr); int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *= attr); int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *= attr); =20 +void kvm_realm_timers_update(struct kvm_vcpu *vcpu); + u64 kvm_phys_timer_read(void); =20 void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu); --=20 2.43.0