From patchwork Thu May 4 11:44:38 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 9711571 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8108960235 for ; Thu, 4 May 2017 11:46:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6519A1FF8F for ; Thu, 4 May 2017 11:46:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 58A2028686; Thu, 4 May 2017 11:46:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E92131FF8F for ; Thu, 4 May 2017 11:46:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752732AbdEDLqq (ORCPT ); Thu, 4 May 2017 07:46:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57744 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752157AbdEDLqo (ORCPT ); Thu, 4 May 2017 07:46:44 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 0882480E7A; Thu, 4 May 2017 11:46:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 0882480E7A Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=eric.auger@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 0882480E7A Received: from localhost.localdomain.com (ovpn-116-214.ams2.redhat.com [10.36.116.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3B39A17999; Thu, 4 May 2017 11:46:32 +0000 (UTC) From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, marc.zyngier@arm.com, christoffer.dall@linaro.org, andre.przywara@arm.com, vijayak@caviumnetworks.com, Vijaya.Kumar@cavium.com, peter.maydell@linaro.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Prasun.Kapoor@cavium.com, drjones@redhat.com, pbonzini@redhat.com, dgilbert@redhat.com, quintela@redhat.com, bjsprakash.linux@gmail.com Subject: [PATCH v6 18/24] KVM: arm64: vgic-its: Add infrastructure for table lookup Date: Thu, 4 May 2017 13:44:38 +0200 Message-Id: <1493898284-29504-19-git-send-email-eric.auger@redhat.com> In-Reply-To: <1493898284-29504-1-git-send-email-eric.auger@redhat.com> References: <1493898284-29504-1-git-send-email-eric.auger@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 04 May 2017 11:46:44 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add a generic scan_its_table() helper whose role consists in scanning a contiguous table located in guest RAM and applying a callback on each entry. Entries can be handled as linked lists since the callback may return an id offset to the next entry and also indicate whether the entry is the last one. Helper functions also are added to compute the device/event ID offset to the next DTE/ITE. compute_next_devid_offset, compute_next_eventid_offset and scan_table will become static in subsequent patches Signed-off-by: Eric Auger Reviewed-by: Christoffer Dall --- v5 -> v6: - add comments about 2d level table scan as suggested by Christoffer - s/lookup_table/scan_its_table - scan_table now return 0 if last elt found and +1 if not found - use int for id - simplify compute_next_devid/eventid_offset v4 -> v5: - use kvm_read_guest v3 -> v4: - remove static to avoid compilation warning - correct size computation in looup_table() - defines now encode the number of bits used for devid and eventid offsets - use BIT() - 1 to encode the max offets --- virt/kvm/arm/vgic/vgic-its.c | 92 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index ea8eb6a..1db7e38 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -221,6 +221,8 @@ static struct its_ite *find_ite(struct vgic_its *its, u32 device_id, #define VITS_TYPER_IDBITS 16 #define VITS_TYPER_DEVBITS 16 +#define VITS_DTE_MAX_DEVID_OFFSET (BIT(14) - 1) +#define VITS_ITE_MAX_EVENTID_OFFSET (BIT(16) - 1) /* * Finds and returns a collection in the ITS collection table. @@ -1694,6 +1696,96 @@ int vgic_its_attr_regs_access(struct kvm_device *dev, return ret; } +u32 compute_next_devid_offset(struct list_head *h, struct its_device *dev) +{ + struct its_device *next; + u32 next_offset; + + if (list_is_last(&dev->dev_list, h)) + return 0; + next = list_next_entry(dev, dev_list); + next_offset = next->device_id - dev->device_id; + + return min_t(u32, next_offset, VITS_DTE_MAX_DEVID_OFFSET); +} + +u32 compute_next_eventid_offset(struct list_head *h, struct its_ite *ite) +{ + struct its_ite *next; + u32 next_offset; + + if (list_is_last(&ite->ite_list, h)) + return 0; + next = list_next_entry(ite, ite_list); + next_offset = next->event_id - ite->event_id; + + return min_t(u32, next_offset, VITS_ITE_MAX_EVENTID_OFFSET); +} + +/** + * entry_fn_t - Callback called on a table entry restore path + * @its: its handle + * @id: id of the entry + * @entry: pointer to the entry + * @opaque: pointer to an opaque data + * + * Return: < 0 on error, 0 if last element was identified, id offset to next + * element otherwise + */ +typedef int (*entry_fn_t)(struct vgic_its *its, u32 id, void *entry, + void *opaque); + +/** + * scan_its_table - Scan a contiguous table in guest RAM and applies a function + * to each entry + * + * @its: its handle + * @base: base gpa of the table + * @size: size of the table in bytes + * @esz: entry size in bytes + * @start_id: the ID of the first entry in the table + * (non zero for 2d level tables) + * @fn: function to apply on each entry + * + * Return: < 0 on error, 0 if last element was identified, 1 otherwise + * (the last element may not be found on second level tables) + */ +int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz, + int start_id, entry_fn_t fn, void *opaque) +{ + void *entry = kzalloc(esz, GFP_KERNEL); + struct kvm *kvm = its->dev->kvm; + unsigned long len = size; + int id = start_id; + gpa_t gpa = base; + int ret; + + while (len > 0) { + int next_offset; + size_t byte_offset; + + ret = kvm_read_guest(kvm, gpa, entry, esz); + if (ret) + goto out; + + next_offset = fn(its, id, entry, opaque); + if (next_offset <= 0) { + ret = next_offset; + goto out; + } + + byte_offset = next_offset * esz; + id += next_offset; + gpa += byte_offset; + len -= byte_offset; + } + ret = 1; + +out: + kfree(entry); + return ret; +} + /** * vgic_its_save_device_tables - Save the device table and all ITT * into guest RAM