From patchwork Wed Mar 10 10:45:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 12127697 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51192C433E0 for ; Wed, 10 Mar 2021 10:45:44 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E721364F7F for ; Wed, 10 Mar 2021 10:45:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E721364F7F Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.95984.181315 (Exim 4.92) (envelope-from ) id 1lJwLJ-0003nn-Vd; Wed, 10 Mar 2021 10:45:29 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 95984.181315; Wed, 10 Mar 2021 10:45:29 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lJwLJ-0003ng-R4; Wed, 10 Mar 2021 10:45:29 +0000 Received: by outflank-mailman (input) for mailman id 95984; Wed, 10 Mar 2021 10:45:28 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lJwLI-0003nO-A8 for xen-devel@lists.xenproject.org; Wed, 10 Mar 2021 10:45:28 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id f13af8c0-4ab6-4ec7-b818-c98ca372a428; Wed, 10 Mar 2021 10:45:27 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 775B5AE7B; Wed, 10 Mar 2021 10:45:26 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: f13af8c0-4ab6-4ec7-b818-c98ca372a428 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1615373126; h=from:from:reply-to: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=ril/4RPeyhImho9ia6AHwhyvGLcmYtjyWfmoZsXmzHI=; b=kCtLZPpVoqLhEwxjvs2rkNk3Vi8Dcw8h4kl3Q53Zz/olDnQvXyadOtBa1UcYJ+UR2wRg6s MDfx2tUyyPFIH4tDYXbp21bAlkf997nM7CnnudqZJOODWgbBWFJ3HmVv/puxnAokAC2hu0 CDBjJ/doFJMCpVAi8LCiIUODcl8FYsY= Subject: [PATCH 2/3] Xen/gnttab: introduce common INVALID_GRANT_{HANDLE,REF} From: Jan Beulich To: Juergen Gross , Boris Ostrovsky , Stefano Stabellini Cc: "xen-devel@lists.xenproject.org" References: <2b326dc6-c624-c97b-f9c4-4cc68dd013ba@suse.com> Message-ID: Date: Wed, 10 Mar 2021 11:45:26 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <2b326dc6-c624-c97b-f9c4-4cc68dd013ba@suse.com> Content-Language: en-US It's not helpful if every driver has to cook its own. Generalize xenbus'es INVALID_GRANT_HANDLE and pcifront's INVALID_GRANT_REF (which shouldn't have expanded to zero to begin with). Use the constants in p2m.c and gntdev.c right away, and update field types where necessary so they would match with the constants' types (albeit without touching struct ioctl_gntdev_grant_ref's ref field, as that's part of the public interface of the kernel and would require introducing a dependency on Xen's grant_table.h public header). Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross --- a/arch/arm/xen/p2m.c +++ b/arch/arm/xen/p2m.c @@ -11,6 +11,7 @@ #include #include +#include #include #include @@ -109,7 +110,7 @@ int set_foreign_p2m_mapping(struct gntta map_ops[i].status = GNTST_general_error; unmap.host_addr = map_ops[i].host_addr, unmap.handle = map_ops[i].handle; - map_ops[i].handle = ~0; + map_ops[i].handle = INVALID_GRANT_HANDLE; if (map_ops[i].flags & GNTMAP_device_map) unmap.dev_bus_addr = map_ops[i].dev_bus_addr; else --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -741,7 +741,7 @@ int set_foreign_p2m_mapping(struct gntta map_ops[i].status = GNTST_general_error; unmap[0].host_addr = map_ops[i].host_addr, unmap[0].handle = map_ops[i].handle; - map_ops[i].handle = ~0; + map_ops[i].handle = INVALID_GRANT_HANDLE; if (map_ops[i].flags & GNTMAP_device_map) unmap[0].dev_bus_addr = map_ops[i].dev_bus_addr; else @@ -751,7 +751,7 @@ int set_foreign_p2m_mapping(struct gntta kmap_ops[i].status = GNTST_general_error; unmap[1].host_addr = kmap_ops[i].host_addr, unmap[1].handle = kmap_ops[i].handle; - kmap_ops[i].handle = ~0; + kmap_ops[i].handle = INVALID_GRANT_HANDLE; if (kmap_ops[i].flags & GNTMAP_device_map) unmap[1].dev_bus_addr = kmap_ops[i].dev_bus_addr; else --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -26,7 +26,7 @@ #include #include -#define INVALID_GRANT_REF (0) + #define INVALID_EVTCHN (-1) struct pci_bus_entry { @@ -42,7 +42,7 @@ struct pcifront_device { struct list_head root_buses; int evtchn; - int gnt_ref; + grant_ref_t gnt_ref; int irq; --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -186,11 +186,11 @@ struct gntdev_grant_map *gntdev_alloc_ma goto err; for (i = 0; i < count; i++) { - add->map_ops[i].handle = -1; - add->unmap_ops[i].handle = -1; + add->map_ops[i].handle = INVALID_GRANT_HANDLE; + add->unmap_ops[i].handle = INVALID_GRANT_HANDLE; if (use_ptemod) { - add->kmap_ops[i].handle = -1; - add->kunmap_ops[i].handle = -1; + add->kmap_ops[i].handle = INVALID_GRANT_HANDLE; + add->kunmap_ops[i].handle = INVALID_GRANT_HANDLE; } } @@ -279,7 +279,7 @@ static int find_grant_ptes(pte_t *pte, u map->grants[pgnr].ref, map->grants[pgnr].domid); gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, - -1 /* handle */); + INVALID_GRANT_HANDLE); return 0; } @@ -297,7 +297,7 @@ int gntdev_map_grant_pages(struct gntdev if (!use_ptemod) { /* Note: it could already be mapped */ - if (map->map_ops[0].handle != -1) + if (map->map_ops[0].handle != INVALID_GRANT_HANDLE) return 0; for (i = 0; i < map->count; i++) { unsigned long addr = (unsigned long) @@ -306,7 +306,7 @@ int gntdev_map_grant_pages(struct gntdev map->grants[i].ref, map->grants[i].domid); gnttab_set_unmap_op(&map->unmap_ops[i], addr, - map->flags, -1 /* handle */); + map->flags, INVALID_GRANT_HANDLE); } } else { /* @@ -332,7 +332,7 @@ int gntdev_map_grant_pages(struct gntdev map->grants[i].ref, map->grants[i].domid); gnttab_set_unmap_op(&map->kunmap_ops[i], address, - flags, -1); + flags, INVALID_GRANT_HANDLE); } } @@ -390,7 +390,7 @@ static int __unmap_grant_pages(struct gn pr_debug("unmap handle=%d st=%d\n", map->unmap_ops[offset+i].handle, map->unmap_ops[offset+i].status); - map->unmap_ops[offset+i].handle = -1; + map->unmap_ops[offset+i].handle = INVALID_GRANT_HANDLE; } return err; } @@ -406,13 +406,15 @@ static int unmap_grant_pages(struct gntd * already unmapped some of the grants. Only unmap valid ranges. */ while (pages && !err) { - while (pages && map->unmap_ops[offset].handle == -1) { + while (pages && + map->unmap_ops[offset].handle == INVALID_GRANT_HANDLE) { offset++; pages--; } range = 0; while (range < pages) { - if (map->unmap_ops[offset+range].handle == -1) + if (map->unmap_ops[offset + range].handle == + INVALID_GRANT_HANDLE) break; range++; } --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -50,6 +50,13 @@ #include #include +/* + * Technically there's no reliably invalid grant reference or grant handle, + * so pick the value that is the most unlikely one to be observed valid. + */ +#define INVALID_GRANT_REF ((grant_ref_t)-1) +#define INVALID_GRANT_HANDLE ((grant_handle_t)-1) + #define GNTTAB_RESERVED_XENSTORE 1 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ --- a/include/xen/xenbus.h +++ b/include/xen/xenbus.h @@ -51,7 +51,6 @@ #define XENBUS_MAX_RING_GRANT_ORDER 4 #define XENBUS_MAX_RING_GRANTS (1U << XENBUS_MAX_RING_GRANT_ORDER) -#define INVALID_GRANT_HANDLE (~0U) /* Register callback to watch this node. */ struct xenbus_watch