From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-4025272-1520452144-2-13947150591623315399 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1520452143; b=WhnDAA8NjSPlfQHRU9dU4p8kLi3f/k886xBKT/imF+Sw9ex TysdPUZUCY0EAH+mUHYMoYYyZbXegbLK/0wSiVj4sTY56oD2uliEV1VhU+FZE47v I4tSV+vISKpc4fzG67nSzsHTrMGsuhWX6KSrv7RXbxPTljCWLYzUOwn2vB3cVxrD 0hKpkdQSPk76zs38rGQdZt8M+nNiYMJlf4sAqIp/nwsVxHgBOzZfaW9+4WkNfxD0 GWJ4lP7ZjA+cDOOfa3GbRmyY4GgEQSW5GNwvT6H7kDUPvGN5vI7Iuvh55cD+CE4t PxnEln0XfhYXTOMHpMmLt0R0r2ntrdxJncI7yNQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1520452143; bh=P5mS3l/Z1dXm5+gkr+57UlS5lb imt4Eks3NS/Z0lPnY=; b=a8K0765pY04mw0AGiThmgwxTYrpaJYP3466rsfB0Ha kLCRHiTzclS5vFDxrgQIQsyGKHqR4ne7xYXPO3tz6kbdMYaNEbm65dWkHg6W7p0P DLq8Wjcbqrk0mNn0Y+NZ8TIVbL20gWtbmEIvJi5fxVx2qmMnGdqrBdJxj++np4UP 6pcuoUwpQzBy+8P9kc8dRTLTXDI76M9F9VlozoPJyEJWqR3EyePl6E0DZ071/Tqv sU+82hNHvyZOdKQqLNUVB/2jbIYB2tO+TI7/iNoIfvpSMKFiWlYRkwJ1hTxSY9xP N5A8UcPuQ4ItxKq+qRLf/dtP1PWThudcrcaBUheH4B6Q== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=-100 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=-100 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965975AbeCGTsi (ORCPT ); Wed, 7 Mar 2018 14:48:38 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45914 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965954AbeCGTsh (ORCPT ); Wed, 7 Mar 2018 14:48:37 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Hildenbrand , Christian Borntraeger Subject: [PATCH 4.14 089/110] KVM: s390: consider epoch index on TOD clock syncs Date: Wed, 7 Mar 2018 11:39:12 -0800 Message-Id: <20180307191051.269268206@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180307191039.748351103@linuxfoundation.org> References: <20180307191039.748351103@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Hildenbrand commit 1575767ef3cf5326701d2ae3075b7732cbc855e4 upstream. For now, we don't take care of over/underflows. Especially underflows are critical: Assume the epoch is currently 0 and we get a sync request for delta=1, meaning the TOD is moved forward by 1 and we have to fix it up by subtracting 1 from the epoch. Right now, this will leave the epoch index untouched, resulting in epoch=-1, epoch_idx=0, which is wrong. We have to take care of over and underflows, also for the VSIE case. So let's factor out calculation into a separate function. Signed-off-by: David Hildenbrand Message-Id: <20180207114647.6220-5-david@redhat.com> Reviewed-by: Christian Borntraeger Fixes: 8fa1696ea781 ("KVM: s390: Multiple Epoch Facility support") Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger [use u8 for idx] Signed-off-by: Greg Kroah-Hartman --- arch/s390/kvm/kvm-s390.c | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -169,6 +169,28 @@ int kvm_arch_hardware_enable(void) static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start, unsigned long end); +static void kvm_clock_sync_scb(struct kvm_s390_sie_block *scb, u64 delta) +{ + u8 delta_idx = 0; + + /* + * The TOD jumps by delta, we have to compensate this by adding + * -delta to the epoch. + */ + delta = -delta; + + /* sign-extension - we're adding to signed values below */ + if ((s64)delta < 0) + delta_idx = -1; + + scb->epoch += delta; + if (scb->ecd & ECD_MEF) { + scb->epdx += delta_idx; + if (scb->epoch < delta) + scb->epdx += 1; + } +} + /* * This callback is executed during stop_machine(). All CPUs are therefore * temporarily stopped. In order not to change guest behavior, we have to @@ -184,13 +206,17 @@ static int kvm_clock_sync(struct notifie unsigned long long *delta = v; list_for_each_entry(kvm, &vm_list, vm_list) { - kvm->arch.epoch -= *delta; kvm_for_each_vcpu(i, vcpu, kvm) { - vcpu->arch.sie_block->epoch -= *delta; + kvm_clock_sync_scb(vcpu->arch.sie_block, *delta); + if (i == 0) { + kvm->arch.epoch = vcpu->arch.sie_block->epoch; + kvm->arch.epdx = vcpu->arch.sie_block->epdx; + } if (vcpu->arch.cputm_enabled) vcpu->arch.cputm_start += *delta; if (vcpu->arch.vsie_block) - vcpu->arch.vsie_block->epoch -= *delta; + kvm_clock_sync_scb(vcpu->arch.vsie_block, + *delta); } } return NOTIFY_OK;