From patchwork Thu Mar 19 04:33:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 11446465 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D087417E6 for ; Thu, 19 Mar 2020 04:33:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A09262072D for ; Thu, 19 Mar 2020 04:33:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ozlabs.org header.i=@ozlabs.org header.b="q3+vPPVH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725874AbgCSEdK (ORCPT ); Thu, 19 Mar 2020 00:33:10 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:36817 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725768AbgCSEdK (ORCPT ); Thu, 19 Mar 2020 00:33:10 -0400 Received: by ozlabs.org (Postfix, from userid 1003) id 48jYtV5Ly0z9sSM; Thu, 19 Mar 2020 15:33:06 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1584592386; bh=QAywpI3JOjIIEUTy46Gfhm93J1pIzZ8maKY0VqoIB8k=; h=Date:From:To:Cc:Subject:From; b=q3+vPPVHAr7M76upYnV+slNMg4FMb0q3It1nUOv0AXZln4DYvSJLAEfoCkkzo+6kQ 984QRjlUMIAfhAAcI+tnYupptPT5aEMY2TLgI9qh9xgyhARFfkUwXlhElphX8UHgeC aCTyDbyQYzf3OJT4bosANZmvKI9jdxSvmmFKlJ6ycT4jbJcjijAUzCqlv122ahbxPw UMpzcNwvx2HNw7wPjkXgavG7E7Rk0MtxO6wJVNLA07i7L5Gix7J/wAKOZpFB6J9Clv SW2gtCB2aQwJAfOfRkO6lF5DwJhjgaiwmXVDMGeZQdJdA00OabsWCrq2ctVaOpHINu V7o5tb8rHCpxg== Date: Thu, 19 Mar 2020 15:33:01 +1100 From: Paul Mackerras To: kvm@vger.kernel.org Cc: kvm-ppc@vger.kernel.org, David Gibson , Ram Pai Subject: [PATCH] KVM: PPC: Book3S HV: Add a capability for enabling secure guests Message-ID: <20200319043301.GA13052@blackberry> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org At present, on Power systems with Protected Execution Facility hardware and an ultravisor, a KVM guest can transition to being a secure guest at will. Userspace (QEMU) has no way of knowing whether a host system is capable of running secure guests. This will present a problem in future when the ultravisor is capable of migrating secure guests from one host to another, because virtualization management software will have no way to ensure that secure guests only run in domains where all of the hosts can support secure guests. This adds a VM capability which has two functions: (a) userspace can query it to find out whether the host can support secure guests, and (b) userspace can enable it for a guest, which allows that guest to become a secure guest. If userspace does not enable it, KVM will return an error when the ultravisor does the hypercall that indicates that the guest is starting to transition to a secure guest. The ultravisor will then abort the transition and the guest will terminate. Signed-off-by: Paul Mackerras Reviewed-by: Greg Kurz Reviewed-by: Cédric Le Goater Reviewed-by: David Gibson --- Note, only compile-tested. Ram, please test. Documentation/virt/kvm/api.rst | 17 +++++++++++++++++ arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/include/asm/kvm_ppc.h | 1 + arch/powerpc/kvm/book3s_hv.c | 13 +++++++++++++ arch/powerpc/kvm/book3s_hv_uvmem.c | 4 ++++ arch/powerpc/kvm/powerpc.c | 13 +++++++++++++ include/uapi/linux/kvm.h | 1 + 7 files changed, 50 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 158d118..a925500 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -5779,6 +5779,23 @@ it hard or impossible to use it correctly. The availability of KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed. Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT. +7.19 KVM_CAP_PPC_SECURE_GUEST +------------------------------ + +:Architectures: ppc + +This capability indicates that KVM is running on a host that has +ultravisor firmware and thus can support a secure guest. On such a +system, a guest can ask the ultravisor to make it a secure guest, +one whose memory is inaccessible to the host except for pages which +are explicitly requested to be shared with the host. The ultravisor +notifies KVM when a guest requests to become a secure guest, and KVM +has the opportunity to veto the transition. + +If present, this capability can be enabled for a VM, meaning that KVM +will allow the transition to secure guest mode. Otherwise KVM will +veto the transition. + 8. Other capabilities. ====================== diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 6e8b8ff..f99b433 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -303,6 +303,7 @@ struct kvm_arch { u8 radix; u8 fwnmi_enabled; u8 secure_guest; + u8 svm_enabled; bool threads_indep; bool nested_enable; pgd_t *pgtable; diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index 406ec46..0733618 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -316,6 +316,7 @@ struct kvmppc_ops { int size); int (*store_to_eaddr)(struct kvm_vcpu *vcpu, ulong *eaddr, void *ptr, int size); + int (*enable_svm)(struct kvm *kvm); int (*svm_off)(struct kvm *kvm); }; diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index fbc55a1..36da720 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -5423,6 +5423,18 @@ static void unpin_vpa_reset(struct kvm *kvm, struct kvmppc_vpa *vpa) } /* + * Enable a guest to become a secure VM. + * Called when the KVM_CAP_PPC_SECURE_GUEST capability is enabled. + */ +static int kvmhv_enable_svm(struct kvm *kvm) +{ + if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR)) + return -EINVAL; + kvm->arch.svm_enabled = 1; + return 0; +} + +/* * IOCTL handler to turn off secure mode of guest * * - Release all device pages @@ -5543,6 +5555,7 @@ static struct kvmppc_ops kvm_ops_hv = { .enable_nested = kvmhv_enable_nested, .load_from_eaddr = kvmhv_load_from_eaddr, .store_to_eaddr = kvmhv_store_to_eaddr, + .enable_svm = kvmhv_enable_svm, .svm_off = kvmhv_svm_off, }; diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index 79b1202..2ad999f 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -216,6 +216,10 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) if (!kvm_is_radix(kvm)) return H_UNSUPPORTED; + /* NAK the transition to secure if not enabled */ + if (!kvm->arch.svm_enabled) + return H_AUTHORITY; + srcu_idx = srcu_read_lock(&kvm->srcu); slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, slots) { diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 62ee66d..c32e6cc2 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -670,6 +670,11 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) (hv_enabled && cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)); break; #endif +#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_UV) + case KVM_CAP_PPC_SECURE_GUEST: + r = hv_enabled && !!firmware_has_feature(FW_FEATURE_ULTRAVISOR); + break; +#endif default: r = 0; break; @@ -2170,6 +2175,14 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, r = kvm->arch.kvm_ops->enable_nested(kvm); break; #endif +#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_UV) + case KVM_CAP_PPC_SECURE_GUEST: + r = -EINVAL; + if (!is_kvmppc_hv_enabled(kvm) || !kvm->arch.kvm_ops->enable_svm) + break; + r = kvm->arch.kvm_ops->enable_svm(kvm); + break; +#endif default: r = -EINVAL; break; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 5e6234c..428c7dd 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1016,6 +1016,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_ARM_INJECT_EXT_DABT 178 #define KVM_CAP_S390_VCPU_RESETS 179 #define KVM_CAP_S390_PROTECTED 180 +#define KVM_CAP_PPC_SECURE_GUEST 181 #ifdef KVM_CAP_IRQ_ROUTING