From patchwork Wed Feb 2 17:21:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank Heimes X-Patchwork-Id: 1587732 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=canonical.com header.i=@canonical.com header.a=rsa-sha256 header.s=20210705 header.b=llBNJ9Xj; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4JppX81QySz9s8s for ; Thu, 3 Feb 2022 04:22:32 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1nFJKt-0004an-6n; Wed, 02 Feb 2022 17:22:27 +0000 Received: from smtp-relay-canonical-0.internal ([10.131.114.83] helo=smtp-relay-canonical-0.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1nFJKq-0004ZY-Tq for kernel-team@lists.ubuntu.com; Wed, 02 Feb 2022 17:22:24 +0000 Received: from T570.fritz.box (p5dce27a2.dip0.t-ipconnect.de [93.206.39.162]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-0.canonical.com (Postfix) with ESMTPSA id 837A640E01 for ; Wed, 2 Feb 2022 17:22:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1643822544; bh=RbfqUbJ5jLGX3GUNRvv5FKyd7xdq4zNTq4SmlaQmmZQ=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=llBNJ9Xj9kf1XxKeugnmt0wkJOzA8NIXHeLP8UlMKhYDsG6qON1NVcfC7NN/eAd5X oO66ikoy0Fye3wjfLDvlDtaPCqssw119LgzSU/MsF9dXxUiRsAnVBIiE8ULGk9rVCn RAzND1ETd/xxee1odCKBYTYZZj+jLCg9anlcwMxy5BBM/vs0fbJp3GsTOH+lha7Jcl sbEc+kpTmTYLhFmUvzQGxPyX8byFd1yHfdttpwHxlrdoOWR95wAxqUvVBuLaA/j7rN 17/s9jAvioyoSvvcCR3MOXyYtHPbD80av/yHGjKi9MAZhg6NLafPP/v8eeQifuDSYa 0KyII5K2Nr7Pg== From: frank.heimes@canonical.com To: kernel-team@lists.ubuntu.com Subject: [J][PATCH 2/2] KVM: s390: Simplify SIGP Set Arch handling Date: Wed, 2 Feb 2022 18:21:38 +0100 Message-Id: <20220202172138.411440-3-frank.heimes@canonical.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220202172138.411440-1-frank.heimes@canonical.com> References: <20220202172138.411440-1-frank.heimes@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Eric Farman BugLink: https://bugs.launchpad.net/bugs/1959735 The Principles of Operations describe the various reasons that each individual SIGP orders might be rejected, and the status bit that are set for each condition. For example, for the Set Architecture order, it states: "If it is not true that all other CPUs in the configu- ration are in the stopped or check-stop state, ... bit 54 (incorrect state) ... is set to one." However, it also states: "... if the CZAM facility is installed, ... bit 55 (invalid parameter) ... is set to one." Since the Configuration-z/Architecture-Architectural Mode (CZAM) facility is unconditionally presented, there is no need to examine each VCPU to determine if it is started/stopped. It can simply be rejected outright with the Invalid Parameter bit. Fixes: b697e435aeee ("KVM: s390: Support Configuration z/Architecture Mode") Signed-off-by: Eric Farman Reviewed-by: Thomas Huth Reviewed-by: Claudio Imbrenda Reviewed-by: David Hildenbrand Reviewed-by: Christian Borntraeger Link: https://lore.kernel.org/r/20211008203112.1979843-2-farman@linux.ibm.com Signed-off-by: Christian Borntraeger (cherry picked from commit 8eeba194a32e0f50329354a696baaa2e3d9accc5 linux-next) Signed-off-by: Frank Heimes --- arch/s390/kvm/sigp.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c index 3dc921e853b6..8aaee2892ec3 100644 --- a/arch/s390/kvm/sigp.c +++ b/arch/s390/kvm/sigp.c @@ -151,22 +151,10 @@ static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu, static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter, u64 *status_reg) { - unsigned int i; - struct kvm_vcpu *v; - bool all_stopped = true; - - kvm_for_each_vcpu(i, v, vcpu->kvm) { - if (v == vcpu) - continue; - if (!is_vcpu_stopped(v)) - all_stopped = false; - } - *status_reg &= 0xffffffff00000000UL; /* Reject set arch order, with czam we're always in z/Arch mode. */ - *status_reg |= (all_stopped ? SIGP_STATUS_INVALID_PARAMETER : - SIGP_STATUS_INCORRECT_STATE); + *status_reg |= SIGP_STATUS_INVALID_PARAMETER; return SIGP_CC_STATUS_STORED; }