From patchwork Fri Sep 3 15:55:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 1524416 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=K2C54jXp; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) 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 ozlabs.org (Postfix) with ESMTPS id 4H1Mxk6zTsz9sCD for ; Sat, 4 Sep 2021 02:02:18 +1000 (AEST) Received: from localhost ([::1]:43030 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mMBdw-0003j0-MC for incoming@patchwork.ozlabs.org; Fri, 03 Sep 2021 12:02:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58054) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mMBXp-0001LG-BI for qemu-devel@nongnu.org; Fri, 03 Sep 2021 11:55:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:24763) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mMBXn-0000eG-Sq for qemu-devel@nongnu.org; Fri, 03 Sep 2021 11:55:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1630684555; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=koATax0ENfqN19XtTaC7VpmNCcm6q32Nu4FPP5NnrNA=; b=K2C54jXpZJMQBeQicu495zja8KoiAOMnhGaRMGsfdaFGWs9nr/4nPcbGmYVZEyLpSQSKmb 85C+hOdXcsJWIlli2dm+gBVxTtdbcSSKqsjjxrAiQWIAZaPwEylG2tnMhm9jjGn7m5yM28 Ry7IJUJybft8zm/iIdH/h0lhnKGQ8vM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-360-J5AVjRvhPdmcYGqR2jHVbQ-1; Fri, 03 Sep 2021 11:55:52 -0400 X-MC-Unique: J5AVjRvhPdmcYGqR2jHVbQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1A599107ACC7; Fri, 3 Sep 2021 15:55:51 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.193.142]) by smtp.corp.redhat.com (Postfix) with ESMTP id F244C60916; Fri, 3 Sep 2021 15:55:48 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v3 08/13] s390x/mmu_helper: avoid setting the storage key if nothing changed Date: Fri, 3 Sep 2021 17:55:09 +0200 Message-Id: <20210903155514.44772-9-david@redhat.com> In-Reply-To: <20210903155514.44772-1-david@redhat.com> References: <20210903155514.44772-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.392, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: "Jason J . Herne" , Thomas Huth , Janosch Frank , David Hildenbrand , Cornelia Huck , Richard Henderson , Halil Pasic , Christian Borntraeger , qemu-s390x@nongnu.org, Claudio Imbrenda Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Avoid setting the key if nothing changed. Reviewed-by: Thomas Huth Signed-off-by: David Hildenbrand --- target/s390x/mmu_helper.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/target/s390x/mmu_helper.c b/target/s390x/mmu_helper.c index de6df928d2..e2b372efd9 100644 --- a/target/s390x/mmu_helper.c +++ b/target/s390x/mmu_helper.c @@ -301,7 +301,7 @@ static void mmu_handle_skey(target_ulong addr, int rw, int *flags) { static S390SKeysClass *skeyclass; static S390SKeysState *ss; - uint8_t key; + uint8_t key, old_key; int rc; /* @@ -337,6 +337,7 @@ static void mmu_handle_skey(target_ulong addr, int rw, int *flags) trace_get_skeys_nonzero(rc); return; } + old_key = key; switch (rw) { case MMU_DATA_LOAD: @@ -360,9 +361,11 @@ static void mmu_handle_skey(target_ulong addr, int rw, int *flags) /* Any store/fetch sets the reference bit */ key |= SK_R; - rc = skeyclass->set_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key); - if (rc) { - trace_set_skeys_nonzero(rc); + if (key != old_key) { + rc = skeyclass->set_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key); + if (rc) { + trace_set_skeys_nonzero(rc); + } } }