From patchwork Tue Dec 19 14:08:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nina Schoetterl-Glausch X-Patchwork-Id: 13498339 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 47C731CA8E; Tue, 19 Dec 2023 14:09:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="V+PJZxFB" Received: from pps.filterd (m0353728.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3BJDhXx2025287; Tue, 19 Dec 2023 14:09:00 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=pJmENGeUiyvalQ6V1XUfovjGn96yhwRUFO3LLN+THKY=; b=V+PJZxFB2gyaTkLGIyu/a3waW+0Rd5Z93I/4HmL0JlpFvWgq6iS1c1OW6BbJqDYGYfyS w/dTLKFpr0D8qef36SRgOiA6Yb8ftz03pXA7PDVradLEVT32gDJhY+mEP1tkloemkcnK 3wkDhXlKwkf1a665x+LhCu+JL9FESF7TKKqGvdmVUu4BqVlelnIGlYAYUb1quTeMTThA CxdORFhkc0hk7DadxEgkIFoRh7HBCd8h2vTtCMaNlIMWZF6GTmbKvv6KoCtCWAx0UAYK /lzmoYIfF+tXtsPap9uNJVi4bsF4hXtVOtGa7ef1jDO6FZ/2Zl73M76yS+WuN8YfSXtC 8A== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3v39nedfpk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 19 Dec 2023 14:09:00 +0000 Received: from m0353728.ppops.net (m0353728.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3BJDheiV026103; Tue, 19 Dec 2023 14:08:59 GMT Received: from ppma12.dal12v.mail.ibm.com (dc.9e.1632.ip4.static.sl-reverse.com [50.22.158.220]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3v39nedfp6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 19 Dec 2023 14:08:59 +0000 Received: from pps.filterd (ppma12.dal12v.mail.ibm.com [127.0.0.1]) by ppma12.dal12v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 3BJCZ4uK029801; Tue, 19 Dec 2023 14:08:59 GMT Received: from smtprelay05.fra02v.mail.ibm.com ([9.218.2.225]) by ppma12.dal12v.mail.ibm.com (PPS) with ESMTPS id 3v1p7sgbm4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 19 Dec 2023 14:08:58 +0000 Received: from smtpav05.fra02v.mail.ibm.com (smtpav05.fra02v.mail.ibm.com [10.20.54.104]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 3BJE8u6N59113964 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 19 Dec 2023 14:08:56 GMT Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1A30B2004B; Tue, 19 Dec 2023 14:08:56 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D234A20040; Tue, 19 Dec 2023 14:08:55 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 19 Dec 2023 14:08:55 +0000 (GMT) From: Nina Schoetterl-Glausch To: Christian Borntraeger , Janosch Frank , David Hildenbrand , Vasily Gorbik , Nina Schoetterl-Glausch , Alexander Gordeev , Claudio Imbrenda , Heiko Carstens Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Sven Schnelle , linux-s390@vger.kernel.org Subject: [PATCH v4 2/4] KVM: s390: vsie: Fix length of facility list shadowed Date: Tue, 19 Dec 2023 15:08:51 +0100 Message-Id: <20231219140854.1042599-3-nsg@linux.ibm.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231219140854.1042599-1-nsg@linux.ibm.com> References: <20231219140854.1042599-1-nsg@linux.ibm.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: k3NxG5exGY-QHJBmmsaBFMMUyRLvoGI0 X-Proofpoint-ORIG-GUID: PXF319mIOfLVzeQpQDNIWMejMcj9jRC5 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-19_08,2023-12-14_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 mlxscore=0 adultscore=0 spamscore=0 mlxlogscore=999 lowpriorityscore=0 impostorscore=0 suspectscore=0 malwarescore=0 phishscore=0 priorityscore=1501 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311290000 definitions=main-2312190105 The length of the facility list accessed when interpretively executing STFLE is the same as the hosts facility list (in case of format-0) The memory following the facility list doesn't need to be accessible. The current VSIE implementation accesses a fixed length that exceeds the guest/host facility list length and can therefore wrongly inject a validity intercept. Instead, find out the host facility list length by running STFLE and copy only as much as necessary when shadowing. Acked-by: David Hildenbrand Reviewed-by: Claudio Imbrenda Acked-by: Heiko Carstens Signed-off-by: Nina Schoetterl-Glausch Reviewed-by: Janosch Frank --- arch/s390/include/asm/facility.h | 6 ++++++ arch/s390/kernel/Makefile | 2 +- arch/s390/kernel/facility.c | 21 +++++++++++++++++++++ arch/s390/kvm/vsie.c | 12 +++++++++++- 4 files changed, 39 insertions(+), 2 deletions(-) create mode 100644 arch/s390/kernel/facility.c diff --git a/arch/s390/include/asm/facility.h b/arch/s390/include/asm/facility.h index 94b6919026df..796007125dff 100644 --- a/arch/s390/include/asm/facility.h +++ b/arch/s390/include/asm/facility.h @@ -111,4 +111,10 @@ static inline void stfle(u64 *stfle_fac_list, int size) preempt_enable(); } +/** + * stfle_size - Actual size of the facility list as specified by stfle + * (number of double words) + */ +unsigned int stfle_size(void); + #endif /* __ASM_FACILITY_H */ diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 353def93973b..7a562b4199c8 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -41,7 +41,7 @@ obj-y += sysinfo.o lgr.o os_info.o ctlreg.o obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o obj-y += entry.o reipl.o kdebugfs.o alternative.o obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o -obj-y += smp.o text_amode31.o stacktrace.o abs_lowcore.o +obj-y += smp.o text_amode31.o stacktrace.o abs_lowcore.o facility.o extra-y += vmlinux.lds diff --git a/arch/s390/kernel/facility.c b/arch/s390/kernel/facility.c new file mode 100644 index 000000000000..f02127219a27 --- /dev/null +++ b/arch/s390/kernel/facility.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 2023 + */ + +#include + +unsigned int stfle_size(void) +{ + static unsigned int size; + unsigned int r; + u64 dummy; + + r = READ_ONCE(size); + if (!r) { + r = __stfle_asm(&dummy, 1) + 1; + WRITE_ONCE(size, r); + } + return r; +} +EXPORT_SYMBOL(stfle_size); diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 35937911724e..fef42e2a80a2 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "kvm-s390.h" #include "gaccess.h" @@ -986,6 +987,10 @@ static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; __u32 fac = READ_ONCE(vsie_page->scb_o->fac); + /* + * Alternate-STFLE-Interpretive-Execution facilities are not supported + * -> format-0 flcb + */ if (fac && test_kvm_facility(vcpu->kvm, 7)) { retry_vsie_icpt(vsie_page); /* @@ -993,8 +998,13 @@ static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) * so we need to mask here before reading. */ fac = fac & 0x7ffffff8U; + /* + * format-0 -> size of nested guest's facility list == guest's size + * guest's size == host's size, since STFLE is interpretatively executed + * using a format-0 for the guest, too. + */ if (read_guest_real(vcpu, fac, &vsie_page->fac, - sizeof(vsie_page->fac))) + stfle_size() * sizeof(u64))) return set_validity_icpt(scb_s, 0x1090U); scb_s->fac = (__u32)(__u64) &vsie_page->fac; }