From patchwork Wed Jul 3 14:30:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 2817821 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id BC46FBF4A1 for ; Wed, 3 Jul 2013 14:31:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E5A5D20034 for ; Wed, 3 Jul 2013 14:31:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE387201B4 for ; Wed, 3 Jul 2013 14:31:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933069Ab3GCObI (ORCPT ); Wed, 3 Jul 2013 10:31:08 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:60690 "EHLO e06smtp13.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932928Ab3GCObC (ORCPT ); Wed, 3 Jul 2013 10:31:02 -0400 Received: from /spool/local by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 3 Jul 2013 15:26:40 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 60CEA1B08061; Wed, 3 Jul 2013 15:30:57 +0100 (BST) Received: from d06av04.portsmouth.uk.ibm.com (d06av04.portsmouth.uk.ibm.com [9.149.37.216]) by b06cxnps3075.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r63EUjxn49807398; Wed, 3 Jul 2013 14:30:45 GMT Received: from d06av04.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av04.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r63EUtii016630; Wed, 3 Jul 2013 08:30:56 -0600 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d06av04.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id r63EUslS016590; Wed, 3 Jul 2013 08:30:55 -0600 From: Cornelia Huck To: Gleb Natapov , Paolo Bonzini Cc: Christian Borntraeger , Heiko Carstens , Martin Schwidefsky , KVM , linux-s390 Subject: [PATCH v4 1/2] KVM: kvm-io: support cookies Date: Wed, 3 Jul 2013 16:30:53 +0200 Message-Id: <1372861854-23043-2-git-send-email-cornelia.huck@de.ibm.com> X-Mailer: git-send-email 1.8.2.2 In-Reply-To: <1372861854-23043-1-git-send-email-cornelia.huck@de.ibm.com> References: <1372861854-23043-1-git-send-email-cornelia.huck@de.ibm.com> X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13070314-2966-0000-0000-0000080AD17C Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add new functions kvm_io_bus_{read,write}_cookie() that allows users of the kvm io infrastructure to use a cookie value to speed up lookup of a device on an io bus. Signed-off-by: Cornelia Huck --- include/linux/kvm_host.h | 4 ++ virt/kvm/kvm_main.c | 106 ++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 95 insertions(+), 15 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index e3aae6d..60e261c9 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -159,8 +159,12 @@ enum kvm_bus { int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val); +int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, const void *val, long cookie); int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, void *val); +int kvm_io_bus_read_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, void *val, long cookie); int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, struct kvm_io_device *dev); int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 1580dd4..c7f5355 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2863,11 +2863,48 @@ static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus, return off; } +static int __kvm_io_bus_write(struct kvm_io_bus *bus, + struct kvm_io_range *range, const void *val) +{ + int idx; + + idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); + if (idx < 0) + return -EOPNOTSUPP; + + while (idx < bus->dev_count && + kvm_io_bus_sort_cmp(range, &bus->range[idx]) == 0) { + if (!kvm_iodevice_write(bus->range[idx].dev, range->addr, + range->len, val)) + return idx; + idx++; + } + + return -EOPNOTSUPP; +} + /* kvm_io_bus_write - called under kvm->slots_lock */ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val) { - int idx; + struct kvm_io_bus *bus; + struct kvm_io_range range; + int r; + + range = (struct kvm_io_range) { + .addr = addr, + .len = len, + }; + + bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); + r = __kvm_io_bus_write(bus, &range, val); + return r < 0 ? r : 0; +} + +/* kvm_io_bus_write_cookie - called under kvm->slots_lock */ +int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, const void *val, long cookie) +{ struct kvm_io_bus *bus; struct kvm_io_range range; @@ -2877,14 +2914,35 @@ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, }; bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); - idx = kvm_io_bus_get_first_dev(bus, addr, len); + + /* First try the device referenced by cookie. */ + if ((cookie >= 0) && (cookie < bus->dev_count) && + (kvm_io_bus_sort_cmp(&range, &bus->range[cookie]) == 0)) + if (!kvm_iodevice_write(bus->range[cookie].dev, addr, len, + val)) + return cookie; + + /* + * cookie contained garbage; fall back to search and return the + * correct cookie value. + */ + return __kvm_io_bus_write(bus, &range, val); +} + +static int __kvm_io_bus_read(struct kvm_io_bus *bus, struct kvm_io_range *range, + void *val) +{ + int idx; + + idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); if (idx < 0) return -EOPNOTSUPP; while (idx < bus->dev_count && kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) { - if (!kvm_iodevice_write(bus->range[idx].dev, addr, len, val)) - return 0; + if (!kvm_iodevice_read(bus->range[idx].dev, range->addr, + range->len, val)) + return idx; idx++; } @@ -2895,9 +2953,9 @@ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, void *val) { - int idx; struct kvm_io_bus *bus; struct kvm_io_range range; + int r; range = (struct kvm_io_range) { .addr = addr, @@ -2905,18 +2963,36 @@ int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, }; bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); - idx = kvm_io_bus_get_first_dev(bus, addr, len); - if (idx < 0) - return -EOPNOTSUPP; + r = __kvm_io_bus_read(bus, &range, val); + return r < 0 ? r : 0; +} - while (idx < bus->dev_count && - kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) { - if (!kvm_iodevice_read(bus->range[idx].dev, addr, len, val)) - return 0; - idx++; - } +/* kvm_io_bus_read_cookie - called under kvm->slots_lock */ +int kvm_io_bus_read_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, void *val, long cookie) +{ + struct kvm_io_bus *bus; + struct kvm_io_range range; - return -EOPNOTSUPP; + range = (struct kvm_io_range) { + .addr = addr, + .len = len, + }; + + bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); + + /* First try the device referenced by cookie. */ + if ((cookie >= 0) && (cookie < bus->dev_count) && + (kvm_io_bus_sort_cmp(&range, &bus->range[cookie]) == 0)) + if (!kvm_iodevice_read(bus->range[cookie].dev, addr, len, + val)) + return cookie; + + /* + * cookie contained garbage; fall back to search and return the + * correct cookie value. + */ + return __kvm_io_bus_read(bus, &range, val); } /* Caller must hold slots_lock. */