From nobody Thu Apr 2 21:51:46 2026 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 14FF931F987; Thu, 26 Mar 2026 13:17:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774531067; cv=none; b=anV4KabhDiHOv3CvDyTUFkqPzuFPn/DuSq5WwGANw/BpjCa6dEtS/FrdajCYThaKAIBG7rANYNNyLtCFBYNvcby43A+p0TsQwU75sAYTGqKME4Xl0xHInqG/I0ORR0mxbv3Bo/U2I5hfY7q9uYj21afafmLzZla8hdfSBwcstjo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774531067; c=relaxed/simple; bh=4YvQrlAPtmyy9nHrH33xmBmKGZf67ZbjsSaFj8cuQVQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bssn/cAukaGmyd+gBFqjYj9GdeRKjR6TRVsiBCMVUafaPWkt6T1frvV3VxyK2QPhFa+oX8IMwf6rM54ec10/OkKCgfJrl5FlaPt+A8yczfH8tTZOd7uqwChdbLDHK3g76iPpYJ9JZ0eeA6us5RqplzSHP1YqY6gExUHPpGb66J0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=K492sBRD; arc=none smtp.client-ip=148.163.158.5 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="K492sBRD" Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 62PMb9A5415280; Thu, 26 Mar 2026 13:17:34 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=AvguOzHMXTpjhhD6T F8/TjFg+mCN4KBzXh8tEjFzrow=; b=K492sBRDCKpbcrBV6TwBAb4FCDIjAEJ0a CoaWQVpfTPcboFh+HLVLgB0E+hWzyymS4dpiK3SpOfdXZ+3nmIGeNkAPNDqhi0v/ fV+RewfQo4MSe9B52lx6hSqHMv5eBOaBid5k9zf7wh0y/WD97cVz5TFuHWYyYsMe MiLJSvkg1+vpXoivrmOdr+nAxzaLOZzAAW8FTecofCm2ldBdgw/qCGxwl4xp8qzT RiBYcL3uhg01GqdBjbvMOHjUYNq60BGdDAEKvF0K57W4xysSAISfeBptlIcseJcB vDtNTu8X/XB4UTbQI+sE77TkSoXCTosWpnAP1xN89K2J8mvC9ZnXw== 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 4d1kumvd6t-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 26 Mar 2026 13:17:34 +0000 (GMT) Received: from pps.filterd (ppma12.dal12v.mail.ibm.com [127.0.0.1]) by ppma12.dal12v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 62QAWCiN031592; Thu, 26 Mar 2026 13:17:33 GMT Received: from smtprelay05.fra02v.mail.ibm.com ([9.218.2.225]) by ppma12.dal12v.mail.ibm.com (PPS) with ESMTPS id 4d25nt36u3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 26 Mar 2026 13:17:33 +0000 Received: from smtpav02.fra02v.mail.ibm.com (smtpav02.fra02v.mail.ibm.com [10.20.54.101]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 62QDHTEX34799990 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 26 Mar 2026 13:17:29 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 85A5F20043; Thu, 26 Mar 2026 13:17:29 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3A1212004F; Thu, 26 Mar 2026 13:17:28 +0000 (GMT) Received: from p-imbrenda.ibmuc.com (unknown [9.111.23.142]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 26 Mar 2026 13:17:28 +0000 (GMT) From: Claudio Imbrenda To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, borntraeger@de.ibm.com, frankja@linux.ibm.com, nrb@linux.ibm.com, seiden@linux.ibm.com, gra@linux.ibm.com, schlameuss@linux.ibm.com, hca@linux.ibm.com, david@kernel.org Subject: [PATCH v5 06/10] KVM: s390: vsie: Fix nested guest memory shadowing Date: Thu, 26 Mar 2026 14:17:15 +0100 Message-ID: <20260326131719.98229-7-imbrenda@linux.ibm.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260326131719.98229-1-imbrenda@linux.ibm.com> References: <20260326131719.98229-1-imbrenda@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-GUID: CjAxtl4CLEis2YSUzC8bNH5cbZIMxNzE X-Proofpoint-ORIG-GUID: CjAxtl4CLEis2YSUzC8bNH5cbZIMxNzE X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMzI2MDA5MyBTYWx0ZWRfX+UREqn4SmtkA v4+wVVWqCaQHhAqtpAKo0jFIY6X8hgQXLpejPKyQuzAmxXaXgozgKVx/Xup2/2+TIo87xJtNINo EB0NDrEhRgphOIcYzy9iqcE07c1KqkX1OeX+TgmhZB6iDfVBiwOMmWGapJRSjAAZ/hsa3G39MV8 0g34S9i36jprLa89Gk3KKt+GXzeY34xeDrYxO4YH/ujNTXNmq09H7/nHDkcCWG92n7GUf3UkPIJ Z45k92vngvLX+oMC//cOnSHo2RDglYGTcARLY6N+lOmN3gPLfV21kMxIZ65hPvmjTnoyDVo5+Tz mzPSKu9/XMpFJgqmP5n3V2iAZZfag/T/AHUdZG1pPAMAp1ONX69h+T5je39YES3Tho2ufbycebF 4mIFdQ4rLmGlMD+LNfo1UwFjUby9iMoJhkaFGeOkArZHgs5wvISyglTf8oUXdrhPMCD2H89+d0r OQg5VBorI1qh8xIlGVQ== X-Authority-Analysis: v=2.4 cv=KbXfcAYD c=1 sm=1 tr=0 ts=69c531ee cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=VnNF1IyMAAAA:8 a=qWq0Kag4T7NBTqZ9-FgA:9 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-03-26_02,2026-03-24_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 impostorscore=0 malwarescore=0 adultscore=0 clxscore=1015 priorityscore=1501 bulkscore=0 lowpriorityscore=0 phishscore=0 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2603260093 Content-Type: text/plain; charset="utf-8" Fix _do_shadow_pte() to use the correct pointer (guest pte instead of nested guest) to set up the new pte. Add a check to return -EOPNOTSUPP if the mapping for the nested guest is writeable but the same page in the guest is only read-only. Signed-off-by: Claudio Imbrenda Fixes: e38c884df921 ("KVM: s390: Switch to new gmap") --- arch/s390/kvm/gaccess.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c index 8fd690255e1b..6bc30f678921 100644 --- a/arch/s390/kvm/gaccess.c +++ b/arch/s390/kvm/gaccess.c @@ -1436,13 +1436,19 @@ static int _do_shadow_pte(struct gmap *sg, gpa_t ra= ddr, union pte *ptep_h, union =20 if (!pgste_get_trylock(ptep_h, &pgste)) return -EAGAIN; - newpte =3D _pte(f->pfn, f->writable, !p, 0); - newpte.s.d |=3D ptep->s.d; - newpte.s.sd |=3D ptep->s.sd; - newpte.h.p &=3D ptep->h.p; - pgste =3D _gmap_ptep_xchg(sg->parent, ptep_h, newpte, pgste, f->gfn, fals= e); - pgste.vsie_notif =3D 1; + newpte =3D _pte(f->pfn, f->writable, !p, ptep_h->s.s); + newpte.s.d |=3D ptep_h->s.d; + newpte.s.sd |=3D ptep_h->s.sd; + newpte.h.p &=3D ptep_h->h.p; + if (!newpte.h.p && !f->writable) { + rc =3D -EOPNOTSUPP; + } else { + pgste =3D _gmap_ptep_xchg(sg->parent, ptep_h, newpte, pgste, f->gfn, fal= se); + pgste.vsie_notif =3D 1; + } pgste_set_unlock(ptep_h, pgste); + if (rc) + return rc; =20 newpte =3D _pte(f->pfn, 0, !p, 0); if (!pgste_get_trylock(ptep, &pgste)) @@ -1477,6 +1483,9 @@ static int _do_shadow_crste(struct gmap *sg, gpa_t ra= ddr, union crste *host, uni newcrste.h.p &=3D oldcrste.h.p; newcrste.s.fc1.vsie_notif =3D 1; newcrste.s.fc1.prefix_notif =3D oldcrste.s.fc1.prefix_notif; + newcrste.s.fc1.s =3D oldcrste.s.fc1.s; + if (!newcrste.h.p && !f->writable) + return -EOPNOTSUPP; } while (!_gmap_crstep_xchg_atomic(sg->parent, host, oldcrste, newcrste, = f->gfn, false)); =20 newcrste =3D _crste_fc1(f->pfn, oldcrste.h.tt, 0, !p); --=20 2.53.0