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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 7B59EC2D0C1 for ; Thu, 19 Dec 2019 21:51:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2E949222C2 for ; Thu, 19 Dec 2019 21:51:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2E949222C2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 010FD8E00F5; Thu, 19 Dec 2019 16:51:55 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EDC198E0184; Thu, 19 Dec 2019 16:51:54 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DCA258E00F5; Thu, 19 Dec 2019 16:51:54 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0161.hostedemail.com [216.40.44.161]) by kanga.kvack.org (Postfix) with ESMTP id B426E8E0184 for ; Thu, 19 Dec 2019 16:51:54 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 42A3A824999B for ; Thu, 19 Dec 2019 21:51:54 +0000 (UTC) X-FDA: 76283238948.19.egg88_2da4f01bc8230 X-HE-Tag: egg88_2da4f01bc8230 X-Filterd-Recvd-Size: 11273 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by imf46.hostedemail.com (Postfix) with ESMTP for ; Thu, 19 Dec 2019 21:51:53 +0000 (UTC) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xBJLlUBu113783; Thu, 19 Dec 2019 16:51:49 -0500 Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0a-001b2d01.pphosted.com with ESMTP id 2x08cg9sjf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 19 Dec 2019 16:51:49 -0500 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id xBJLjm8p006582; Thu, 19 Dec 2019 21:51:48 GMT Received: from b01cxnp22034.gho.pok.ibm.com (b01cxnp22034.gho.pok.ibm.com [9.57.198.24]) by ppma02dal.us.ibm.com with ESMTP id 2wvqc7ed5t-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 19 Dec 2019 21:51:48 +0000 Received: from b01ledav004.gho.pok.ibm.com (b01ledav004.gho.pok.ibm.com [9.57.199.109]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xBJLpmYc38928882 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 19 Dec 2019 21:51:48 GMT Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1A376112064; Thu, 19 Dec 2019 21:51:48 +0000 (GMT) Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 66C2B112061; Thu, 19 Dec 2019 21:51:47 +0000 (GMT) Received: from suka-w540.usor.ibm.com (unknown [9.70.94.45]) by b01ledav004.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 19 Dec 2019 21:51:47 +0000 (GMT) From: Sukadev Bhattiprolu To: Michael Ellerman , Paul Mackerras , linuxram@us.ibm.com Cc: bharata@linux.ibm.com, linuxppc-dev@ozlabs.org, kvm-ppc@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v4 2/2] KVM: PPC: Implement H_SVM_INIT_ABORT hcall Date: Thu, 19 Dec 2019 13:51:46 -0800 Message-Id: <20191219215146.27278-2-sukadev@linux.ibm.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20191219215146.27278-1-sukadev@linux.ibm.com> References: <20191219215146.27278-1-sukadev@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-19_07:2019-12-17,2019-12-19 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=2 lowpriorityscore=0 mlxlogscore=999 malwarescore=0 spamscore=0 adultscore=0 clxscore=1015 bulkscore=0 mlxscore=0 priorityscore=1501 phishscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912190162 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Implement the H_SVM_INIT_ABORT hcall which the Ultravisor can use to abort an SVM after it has issued the H_SVM_INIT_START and before the H_SVM_INIT_DONE hcalls. This hcall could be used when Ultravisor encounters security violations or other errors when starting an SVM. Note that this hcall is different from UV_SVM_TERMINATE ucall which is used by HV to terminate/cleanup an VM that has becore secure. The H_SVM_INIT_ABORT should basically undo operations that were done since the H_SVM_INIT_START hcall - i.e page-out all the VM pages back to normal memory, and terminate the SVM. (If we do not bring the pages back to normal memory, the text/data of the VM would be stuck in secure memory and since the SVM did not go secure, its MSR_S bit will be clear and the VM wont be able to access its pages even to do a clean exit). Based on patches and discussion with Paul Mackerras, Ram Pai and Bharata Rao. Signed-off-by: Ram Pai Signed-off-by: Sukadev Bhattiprolu Signed-off-by: Bharata B Rao --- Changelog[v4]: - [Bharata Rao] Add missing rcu locking - [Paul Mackerras] simplify code that walks memslots - Add a check to ensure that H_SVM_INIT_ABORT is called before H_SVM_INIT_DONE hcall (i.e the SVM is not already secure). Changelog[v3]: - Rather than pass the NIP/MSR as parameters, load them into SRR0/SRR1 (like we do with other registers) and terminate the VM after paging out pages - Move the code to add a skip_page_out parameter into a separate patch. Changelog[v2]: [Paul Mackerras] avoid returning to UV "one last time" after the state is cleaned up. So, we now have H_SVM_INIT_ABORT: - take the VM's NIP/MSR register states as parameters - inherit the state of other registers as at UV_ESM call. After cleaning up the partial state, HV uses these to return directly to the VM with a failed UV_ESM call. --- Documentation/powerpc/ultravisor.rst | 57 +++++++++++++++++++++ arch/powerpc/include/asm/hvcall.h | 1 + arch/powerpc/include/asm/kvm_book3s_uvmem.h | 6 +++ arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kvm/book3s_hv.c | 3 ++ arch/powerpc/kvm/book3s_hv_uvmem.c | 26 ++++++++++ 6 files changed, 94 insertions(+) diff --git a/Documentation/powerpc/ultravisor.rst b/Documentation/powerpc/ultravisor.rst index 730854f73830..8c114c071bfa 100644 --- a/Documentation/powerpc/ultravisor.rst +++ b/Documentation/powerpc/ultravisor.rst @@ -948,6 +948,63 @@ Use cases up its internal state for this virtual machine. +H_SVM_INIT_ABORT +---------------- + + Abort the process of securing an SVM. + +Syntax +~~~~~~ + +.. code-block:: c + + uint64_t hypercall(const uint64_t H_SVM_INIT_ABORT) + +Return values +~~~~~~~~~~~~~ + + One of the following values: + + * H_PARAMETER on successfully cleaning up the state, + Hypervisor will return this value to the + **guest**, to indicate that the underlying + UV_ESM ultracall failed. + + * H_UNSUPPORTED if called from the wrong context (e.g. from + an SVM or before an H_SVM_INIT_START hypercall). + +Description +~~~~~~~~~~~ + + Abort the process of securing a virtual machine. This call must + be made after a prior call to ``H_SVM_INIT_START`` hypercall and + before a call to ``H_SVM_INIT_DONE``. + + On entry into this hypercall the non-volatile GPRs and FPRs are + expected to contain the values they had at the time the VM issued + the UV_ESM ultracall. Further ``SRR0`` is expected to contain the + address of the instruction after the ``UV_ESM`` ultracall and ``SRR1`` + the MSR value with which to return to the VM. + + This hypercall will cleanup any partial state that was established for + the VM since the prior ``H_SVM_INIT_START`` hypercall, including paging + out pages that were paged-into secure memory, and issue the + ``UV_SVM_TERMINATE`` ultracall to terminate the VM. + + After the partial state is cleaned up, control returns to the VM + (**not Ultravisor**), at the address specified in ``SRR0`` with the + MSR values set to the value in ``SRR1``. + +Use cases +~~~~~~~~~ + + If after a successful call to ``H_SVM_INIT_START``, the Ultravisor + encounters an error while securing a virtual machine, either due + to lack of resources or because the VM's security information could + not be validated, Ultravisor informs the Hypervisor about it. + Hypervisor should use this call to clean up any internal state for + this virtual machine and return to the VM. + H_SVM_PAGE_IN ------------- diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index 13bd870609c3..e90c073e437e 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -350,6 +350,7 @@ #define H_SVM_PAGE_OUT 0xEF04 #define H_SVM_INIT_START 0xEF08 #define H_SVM_INIT_DONE 0xEF0C +#define H_SVM_INIT_ABORT 0xEF14 /* Values for 2nd argument to H_SET_MODE */ #define H_SET_MODE_RESOURCE_SET_CIABR 1 diff --git a/arch/powerpc/include/asm/kvm_book3s_uvmem.h b/arch/powerpc/include/asm/kvm_book3s_uvmem.h index 3cf8425b9838..5a9834e0e2d1 100644 --- a/arch/powerpc/include/asm/kvm_book3s_uvmem.h +++ b/arch/powerpc/include/asm/kvm_book3s_uvmem.h @@ -19,6 +19,7 @@ unsigned long kvmppc_h_svm_page_out(struct kvm *kvm, unsigned long kvmppc_h_svm_init_start(struct kvm *kvm); unsigned long kvmppc_h_svm_init_done(struct kvm *kvm); int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn); +unsigned long kvmppc_h_svm_init_abort(struct kvm *kvm); void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free, struct kvm *kvm, bool skip_page_out); #else @@ -62,6 +63,11 @@ static inline unsigned long kvmppc_h_svm_init_done(struct kvm *kvm) return H_UNSUPPORTED; } +static inline unsigned long kvmppc_h_svm_init_abort(struct kvm *kvm) +{ + return H_UNSUPPORTED; +} + static inline int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn) { return -EFAULT; diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 577ca95fac7c..8310c0407383 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -278,6 +278,7 @@ struct kvm_resize_hpt; /* Flag values for kvm_arch.secure_guest */ #define KVMPPC_SECURE_INIT_START 0x1 /* H_SVM_INIT_START has been called */ #define KVMPPC_SECURE_INIT_DONE 0x2 /* H_SVM_INIT_DONE completed */ +#define KVMPPC_SECURE_INIT_ABORT 0x4 /* H_SVM_INIT_ABORT issued */ struct kvm_arch { unsigned int lpid; diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 66d5312be16b..1b22f2c7ad1b 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1099,6 +1099,9 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) case H_SVM_INIT_DONE: ret = kvmppc_h_svm_init_done(vcpu->kvm); break; + case H_SVM_INIT_ABORT: + ret = kvmppc_h_svm_init_abort(vcpu->kvm); + break; default: return RESUME_HOST; diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index 9a5bbad7d87e..31484a861117 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -287,6 +287,32 @@ void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free, } } +unsigned long kvmppc_h_svm_init_abort(struct kvm *kvm) +{ + int srcu_idx; + struct kvm_memory_slot *memslot; + + /* + * Expect to be called only after INIT_START and before INIT_DONE. + * If INIT_DONE was completed, use normal VM termination sequence. + */ + if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START) || + (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)) + return H_UNSUPPORTED; + + srcu_idx = srcu_read_lock(&kvm->srcu); + + kvm_for_each_memslot(memslot, kvm_memslots(kvm)) + kvmppc_uvmem_drop_pages(memslot, kvm, false); + + srcu_read_unlock(&kvm->srcu, srcu_idx); + + kvm->arch.secure_guest = 0; + uv_svm_terminate(kvm->arch.lpid); + + return H_PARAMETER; +} + /* * Get a free device PFN from the pool * -- 2.17.2