From nobody Tue Nov 11 20:50:39 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1565609440; cv=none; d=zoho.com; s=zohoarc; b=Oj9DLBRyvSwUe0XgrlWxH3siuM4INxI/tln2904+bAWuk720oVMDfF4SWyDfIT6PFqQbKcnCNJ6d6C1OcL7hEs79vE6zJjjxlTbi8PxwiHgFNJUyQtmaWwJey9oN3ejhjS4fi58UmzPFHDlQxIkMpyxUcbCjgzEnxw8LdRD9nzw= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1565609440; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=MTh0wL46nt9aeMF1PFfWqg+bThWZaldmD0XwAL5wFaI=; b=djMNGnQAntsk8VC82oU+z4AWyZ2Uam7iX/CW29piaAuIW5fBVUhSG5/l18EpmrVQGHFjdb5sr8yTXmkfOBikvJU8mHQMFnrn9aX41AHUHzxu6MUfoZERYZpYdg+2qlD29PkjpjzwFxQ3JV8iTfzrDFcnheh4aHVo2+eXXSgexCg= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1565609440610518.3131200437969; Mon, 12 Aug 2019 04:30:40 -0700 (PDT) Received: from localhost ([::1]:44468 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hx8X9-0001cj-Pm for importer@patchew.org; Mon, 12 Aug 2019 07:30:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34717) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hx8Uh-0004gg-5p for qemu-devel@nongnu.org; Mon, 12 Aug 2019 07:28:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hx8Uf-0002hE-Kr for qemu-devel@nongnu.org; Mon, 12 Aug 2019 07:28:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13274) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hx8Ud-0002eY-Pd; Mon, 12 Aug 2019 07:28:05 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EDF76C015C30; Mon, 12 Aug 2019 11:28:01 +0000 (UTC) Received: from t460s.redhat.com (ovpn-117-110.ams2.redhat.com [10.36.117.110]) by smtp.corp.redhat.com (Postfix) with ESMTP id 21F40600C4; Mon, 12 Aug 2019 11:27:59 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Date: Mon, 12 Aug 2019 13:27:37 +0200 Message-Id: <20190812112737.6652-7-david@redhat.com> In-Reply-To: <20190812112737.6652-1-david@redhat.com> References: <20190812112737.6652-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Mon, 12 Aug 2019 11:28:02 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH-for-4.2 v1 6/6] s390x/mmu: Factor out storage key handling 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: Thomas Huth , Janosch Frank , David Hildenbrand , Cornelia Huck , Halil Pasic , Christian Borntraeger , qemu-s390x@nongnu.org, Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" Factor it out, add a comment how it all works, and also use it in the REAL MMU. Signed-off-by: David Hildenbrand Reviewed-by: Cornelia Huck --- target/s390x/mmu_helper.c | 114 +++++++++++++++++++++++--------------- 1 file changed, 69 insertions(+), 45 deletions(-) diff --git a/target/s390x/mmu_helper.c b/target/s390x/mmu_helper.c index ba4b460ac6..d2c9285d0a 100644 --- a/target/s390x/mmu_helper.c +++ b/target/s390x/mmu_helper.c @@ -334,6 +334,73 @@ static int mmu_translate_asce(CPUS390XState *env, targ= et_ulong vaddr, return r; } =20 +static void mmu_handle_skey(target_ulong addr, int rw, int *flags) +{ + static S390SKeysClass *skeyclass; + static S390SKeysState *ss; + uint8_t key; + int rc; + + if (unlikely(!ss)) { + ss =3D s390_get_skeys_device(); + skeyclass =3D S390_SKEYS_GET_CLASS(ss); + } + + /* + * Whenever we create a new TLB entry, we set the storage key reference + * bit. In case we allow write accesses, we set the storage key change + * bit. Whenever the guest changes the storage key, we have to flush t= he + * TLBs of all CPUs (the whole TLB or all affected entries), so that t= he + * next reference/change will result in an MMU fault and make us prope= rly + * update the storage key here. + * + * Note 1: "record of references ... is not necessarily accurate", + * "change bit may be set in case no storing has occurred". + * -> We can set reference/change bits even on exceptions. + * Note 2: certain accesses seem to ignore storage keys. For example, + * DAT translation does not set reference bits for table acces= ses. + * + * TODO: key-controlled protection. Only CPU accesses make use of the + * PSW key. CSS accesses are different - we have to pass in the = key. + * + * TODO: we have races between getting and setting the key. + */ + if (addr < ram_size) { + rc =3D skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key); + if (rc) { + trace_get_skeys_nonzero(rc); + return; + } + + switch (rw) { + case MMU_DATA_LOAD: + case MMU_INST_FETCH: + /* + * The TLB entry has to remain write-protected on read-faults = if + * the storage key does not indicate a change already. Otherwi= se + * we might miss setting the change bit on write accesses. + */ + if (!(key & SK_C)) { + *flags &=3D ~PAGE_WRITE; + } + break; + case MMU_DATA_STORE: + key |=3D SK_C; + break; + default: + g_assert_not_reached(); + } + + /* Any store/fetch sets the reference bit */ + key |=3D SK_R; + + rc =3D skeyclass->set_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key); + if (rc) { + trace_set_skeys_nonzero(rc); + } + } +} + /** * Translate a virtual (logical) address into a physical (absolute) addres= s. * @param vaddr the virtual address @@ -347,16 +414,8 @@ static int mmu_translate_asce(CPUS390XState *env, targ= et_ulong vaddr, int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t= asc, target_ulong *raddr, int *flags, bool exc) { - static S390SKeysState *ss; - static S390SKeysClass *skeyclass; uint64_t asce; int r =3D -1; - uint8_t key; - - if (unlikely(!ss)) { - ss =3D s390_get_skeys_device(); - skeyclass =3D S390_SKEYS_GET_CLASS(ss); - } =20 *flags =3D PAGE_READ | PAGE_WRITE | PAGE_EXEC; if (is_low_address(vaddr & TARGET_PAGE_MASK) && lowprot_enabled(env, a= sc)) { @@ -414,42 +473,7 @@ nodat: /* Convert real address -> absolute address */ *raddr =3D mmu_real2abs(env, *raddr); =20 - if (*raddr < ram_size) { - r =3D skeyclass->get_skeys(ss, *raddr / TARGET_PAGE_SIZE, 1, &key); - if (r) { - trace_get_skeys_nonzero(r); - return 0; - } - - switch (rw) { - case MMU_DATA_LOAD: - case MMU_INST_FETCH: - /* - * The TLB entry has to remain write-protected on read-faults = if - * the storage key does not indicate a change already. Otherwi= se - * we might miss setting the change bit on write accesses. - */ - if (!(key & SK_C)) { - *flags &=3D ~PAGE_WRITE; - } - break; - case MMU_DATA_STORE: - key |=3D SK_C; - break; - default: - g_assert_not_reached(); - } - - /* Any store/fetch sets the reference bit */ - key |=3D SK_R; - - r =3D skeyclass->set_skeys(ss, *raddr / TARGET_PAGE_SIZE, 1, &key); - if (r) { - trace_set_skeys_nonzero(r); - return 0; - } - } - + mmu_handle_skey(*raddr, rw, flags); return 0; } =20 @@ -567,6 +591,6 @@ int mmu_translate_real(CPUS390XState *env, target_ulong= raddr, int rw, =20 *addr =3D mmu_real2abs(env, raddr & TARGET_PAGE_MASK); =20 - /* TODO: storage key handling */ + mmu_handle_skey(*addr, rw, flags); return 0; } --=20 2.21.0