From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90483C43603 for ; Thu, 12 Dec 2019 12:28:44 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6403620663 for ; Thu, 12 Dec 2019 12:28:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6403620663 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:58590 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ifNaF-0000xa-H8 for qemu-devel@archiver.kernel.org; Thu, 12 Dec 2019 07:28:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:35591) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ifNZO-0000HH-3j for qemu-devel@nongnu.org; Thu, 12 Dec 2019 07:27:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ifNZM-0006DW-GA for qemu-devel@nongnu.org; Thu, 12 Dec 2019 07:27:49 -0500 Received: from 5.mo173.mail-out.ovh.net ([46.105.40.148]:49897) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ifNZM-00061T-7u for qemu-devel@nongnu.org; Thu, 12 Dec 2019 07:27:48 -0500 Received: from player750.ha.ovh.net (unknown [10.108.57.178]) by mo173.mail-out.ovh.net (Postfix) with ESMTP id 0F1A412950A for ; Thu, 12 Dec 2019 13:27:38 +0100 (CET) Received: from kaod.org (lns-bzn-46-82-253-208-248.adsl.proxad.net [82.253.208.248]) (Authenticated sender: groug@kaod.org) by player750.ha.ovh.net (Postfix) with ESMTPSA id 8A8BAD2EFBF3; Thu, 12 Dec 2019 12:27:26 +0000 (UTC) Date: Thu, 12 Dec 2019 13:27:23 +0100 From: Greg Kurz To: Bharata B Rao Subject: Re: [PATCH v2 ppc-for-5.0 2/2] ppc/spapr: Support reboot of secure pseries guest Message-ID: <20191212132723.5fdfee47@bahia.tlslab.ibm.com> In-Reply-To: <20191212055059.9399-3-bharata@linux.ibm.com> References: <20191212055059.9399-1-bharata@linux.ibm.com> <20191212055059.9399-3-bharata@linux.ibm.com> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Ovh-Tracer-Id: 3619205253579119094 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedufedrudeljedggedvucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepfffhvffukfgjfhfogggtgfesthejredtredtvdenucfhrhhomhepifhrvghgucfmuhhriicuoehgrhhouhhgsehkrghougdrohhrgheqnecukfhppedtrddtrddtrddtpdekvddrvdehfedrvddtkedrvdegkeenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepphhlrgihvghrjeehtddrhhgrrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpehgrhhouhhgsehkrghougdrohhrghdprhgtphhtthhopehqvghmuhdquggvvhgvlhesnhhonhhgnhhurdhorhhgnecuvehluhhsthgvrhfuihiivgeptd X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 46.105.40.148 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , linuxram@us.ibm.com, qemu-devel@nongnu.org, paulus@ozlabs.org, qemu-ppc@nongnu.org, david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 12 Dec 2019 11:20:59 +0530 Bharata B Rao wrote: > A pseries guest can be run as a secure guest on Ultravisor-enabled > POWER platforms. When such a secure guest is reset, we need to > release/reset a few resources both on ultravisor and hypervisor side. > This is achieved by invoking this new ioctl KVM_PPC_SVM_OFF from the > machine reset path. > > As part of this ioctl, the secure guest is essentially transitioned > back to normal mode so that it can reboot like a regular guest and > become secure again. > > This ioctl has no effect when invoked for a normal guest. If this ioctl > fails for a secure guest, the guest is terminated. > > Signed-off-by: Bharata B Rao > --- > hw/ppc/spapr.c | 15 +++++++++++++++ > target/ppc/kvm.c | 7 +++++++ > target/ppc/kvm_ppc.h | 6 ++++++ > 3 files changed, 28 insertions(+) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index f11422fc41..25e1a3446e 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -1597,6 +1597,21 @@ static void spapr_machine_reset(MachineState *machine) > void *fdt; > int rc; > > + /* > + * KVM_PPC_SVM_OFF ioctl can fail for secure guests, check and > + * exit in that case. However check for -ENOTTY explicitly > + * to ensure that we don't terminate normal guests that are > + * running on kernels which don't support this ioctl. > + * > + * Also, this ioctl returns 0 for normal guests on kernels where > + * this ioctl is supported. > + */ > + rc = kvmppc_svm_off(); > + if (rc && rc != -ENOTTY) { This ioctl can also return -EINVAL if the ultravisor actually failed to move the guest back to non-secure mode or -EBUSY if a vCPU is still running. I agree that the former deserve the VM to be terminated. What about the latter ? Can this happen and if yes, why ? Should we try again as suggested by Alexey ? Could this reveal a bug in QEMU, in which case we should maybe abort ? > + error_report("Reset of secure guest failed, exiting..."); > + exit(EXIT_FAILURE); > + } > + > spapr_caps_apply(spapr); > > first_ppc_cpu = POWERPC_CPU(first_cpu); > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c > index 7406d18945..1a86fa4f0c 100644 > --- a/target/ppc/kvm.c > +++ b/target/ppc/kvm.c > @@ -2900,3 +2900,10 @@ void kvmppc_set_reg_tb_offset(PowerPCCPU *cpu, int64_t tb_offset) > kvm_set_one_reg(cs, KVM_REG_PPC_TB_OFFSET, &tb_offset); > } > } > + > +int kvmppc_svm_off(void) > +{ > + KVMState *s = KVM_STATE(current_machine->accelerator); > + > + return kvm_vm_ioctl(s, KVM_PPC_SVM_OFF); > +} > diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h > index 47b08a4030..5cc812e486 100644 > --- a/target/ppc/kvm_ppc.h > +++ b/target/ppc/kvm_ppc.h > @@ -37,6 +37,7 @@ int kvmppc_booke_watchdog_enable(PowerPCCPU *cpu); > target_ulong kvmppc_configure_v3_mmu(PowerPCCPU *cpu, > bool radix, bool gtse, > uint64_t proc_tbl); > +int kvmppc_svm_off(void); > #ifndef CONFIG_USER_ONLY > bool kvmppc_spapr_use_multitce(void); > int kvmppc_spapr_enable_inkernel_multitce(void); > @@ -201,6 +202,11 @@ static inline target_ulong kvmppc_configure_v3_mmu(PowerPCCPU *cpu, > return 0; > } > > +static inline int kvmppc_svm_off(void) > +{ > + return 0; > +} > + > static inline void kvmppc_set_reg_ppc_online(PowerPCCPU *cpu, > unsigned int online) > {