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 B7B2042AFB7; Mon, 5 Oct 2026 09:08:13 +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=1791191298; cv=none; b=vE0XWTQ50FmK+mrysL7yq7ojH7BP5yVDTcGFiy6CzHYc8j7hFkqRdN4ihxi+B57ERZj+h57iBhqeXss9o05tnP1HVp3MkWqH0z9YIwIIMJ06dL62aNOhgqkZK0qPvw8r5ZouqPNHRf4xMTOqLkci53vpp/jjleIwpV/TalHDRNI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791191298; c=relaxed/simple; bh=tQPgXa0jI7YAYMnIJ4TZ6BAVtiDhJcnzdYxdyAnW4NQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GZdeCkVIEsOv4K9pkldo+NRmS/eSW5eBOEPj55vZc7m+iETO6oXALCOhS7/Ot0CV4CZwFx8lwL0qKoCc3LTDpaaC6ky1Yc+G9CauAdYNYWZnsPBHN8wkZEB1YK2/8x5tmtj1QkAm08c3Dqm7D5bOgnzILGxf8CVTfo1QHakeu7k= 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=hihwFwTX; 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="hihwFwTX" 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 C34861684; Mon, 5 Oct 2026 02:08:09 -0700 (PDT) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.2.197.99]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 100443F66F; Mon, 5 Oct 2026 02:08:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1791191293; bh=tQPgXa0jI7YAYMnIJ4TZ6BAVtiDhJcnzdYxdyAnW4NQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hihwFwTXrTV59Vkez3RHvIk46uXsPbnD7qLKfZhgJuD5n45XvAqIv96vpzVYEPrXm SoR1yIaQ0vUAfrRX3qjCCWB1+UhgQP3w7xLcdlyAYcJvRkv5TQwZQ3O7dl9IUIc3vT KN7j3eR4+H7Ku1Z3c3drd6plDdyukmmtOYOVfmAM= From: Suzuki K Poulose To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: maz@kernel.org, will@kernel.org, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, steven.price@arm.com, aneesh.kumar@kernel.org, oupton@kernel.org, gshan@redhat.com, joey.gouly@arm.com, tabba@google.com, yuzenghui@huawei.com, linux-coco@lists.linux.dev, gankulkarni@os.amperecomputing.com, sdonthineni@nvidia.com, alpergun@google.com, fj0570is@fujitsu.com, WeiLin.Chang@arm.com, lpieralisi@kernel.org, enju.kohei@fujitsu.com, sudeep.holla@arm.com, jonathan.cameron@oss.qualcomm.com, Suzuki K Poulose , Fuad Tabba Subject: [PATCH v22 02/23] KVM: arm64: Disable Steal time accounting for protected guests Date: Mon, 5 Oct 2026 10:07:33 +0100 Message-ID: <20261005090754.2140522-3-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261005090754.2140522-1-suzuki.poulose@arm.com> References: <20261005090754.2140522-1-suzuki.poulose@arm.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit PVTIME support is advertised by KVM_CAP_STEAL_TIME, which doesn't take into account the kvm instance. Even with that, a VMM could skip the CAP check and proceed to configure the PVTIME as we don't do further check on the DEVICE_CTRL. Tighten this up by passing the KVM instance around wherever possible and catch things early. Reviewed-by: Fuad Tabba Tested-by: Gavin Shan Signed-off-by: Suzuki K Poulose --- arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/kvm/arm.c | 2 +- arch/arm64/kvm/pvtime.c | 14 +++++++------- 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 27fe0cd5b2d7a..286489a69dff5 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1346,7 +1346,7 @@ long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu); gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu); void kvm_update_stolen_time(struct kvm_vcpu *vcpu); -bool kvm_arm_pvtime_supported(void); +bool kvm_arm_pvtime_supported(struct kvm *kvm); int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 8b080804bc90b..db36815630790 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -447,7 +447,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = system_supports_mte(); break; case KVM_CAP_STEAL_TIME: - r = kvm_arm_pvtime_supported(); + r = kvm_arm_pvtime_supported(kvm); break; case KVM_CAP_ARM_EL1_32BIT: r = cpus_have_final_cap(ARM64_HAS_32BIT_EL1); diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c index 4ceabaa4c30bd..579e0a4720ad2 100644 --- a/arch/arm64/kvm/pvtime.c +++ b/arch/arm64/kvm/pvtime.c @@ -67,9 +67,9 @@ gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu) return base; } -bool kvm_arm_pvtime_supported(void) +bool kvm_arm_pvtime_supported(struct kvm *kvm) { - return !!sched_info_on(); + return !!sched_info_on() && (!kvm || !kvm_vm_is_protected(kvm)); } int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, @@ -81,8 +81,8 @@ int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, int ret = 0; int idx; - if (!kvm_arm_pvtime_supported() || - attr->attr != KVM_ARM_VCPU_PVTIME_IPA) + if (!kvm_arm_pvtime_supported(kvm) || + (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)) return -ENXIO; if (get_user(ipa, user)) @@ -110,8 +110,8 @@ int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu, u64 __user *user = (u64 __user *)attr->addr; u64 ipa; - if (!kvm_arm_pvtime_supported() || - attr->attr != KVM_ARM_VCPU_PVTIME_IPA) + if (!kvm_arm_pvtime_supported(vcpu->kvm) || + (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)) return -ENXIO; ipa = vcpu->arch.steal.base; @@ -126,7 +126,7 @@ int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu, { switch (attr->attr) { case KVM_ARM_VCPU_PVTIME_IPA: - if (kvm_arm_pvtime_supported()) + if (kvm_arm_pvtime_supported(vcpu->kvm)) return 0; } return -ENXIO; -- 2.43.0