From patchwork Wed Apr 29 08:25:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juergen Gross X-Patchwork-Id: 11516399 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AA0AE92A for ; Wed, 29 Apr 2020 08:26:48 +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 9076B206D9 for ; Wed, 29 Apr 2020 08:26:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9076B206D9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jTi2H-0002UH-9t; Wed, 29 Apr 2020 08:25:41 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jTi2F-0002UB-RJ for xen-devel@lists.xenproject.org; Wed, 29 Apr 2020 08:25:39 +0000 X-Inumbo-ID: 01264b7e-89f3-11ea-9887-bc764e2007e4 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 01264b7e-89f3-11ea-9887-bc764e2007e4; Wed, 29 Apr 2020 08:25:38 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 8CF7CAB3D; Wed, 29 Apr 2020 08:25:36 +0000 (UTC) From: Juergen Gross To: xen-devel@lists.xenproject.org Subject: [PATCH v2] tools/xenstore: don't store domU's mfn of ring page in xenstored Date: Wed, 29 Apr 2020 10:25:34 +0200 Message-Id: <20200429082534.4143-1-jgross@suse.com> X-Mailer: git-send-email 2.16.4 X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Ian Jackson , Wei Liu Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" The XS_INTRODUCE command has two parameters: the mfn (or better: gfn) of the domain's xenstore ring page and the event channel of the domain for communicating with Xenstore. The gfn is not really needed. It is stored in the per-domain struct in xenstored and in case of another XS_INTRODUCE for the domain it is tested to match the original value. If it doesn't match the command is aborted via EINVAL. Today there aren't multiple XS_INTRODUCE requests for the same domain issued, so the mfn/gfn can just be ignored and multiple XS_INTRODUCE commands can be rejected without testing the mfn/gfn. Signed-off-by: Juergen Gross Acked-by: Andrew Cooper --- V2: - remove mfn from struct domain (Julien Grall) - replace mfn by gfn in comments (Julien Grall) --- tools/xenstore/xenstored_domain.c | 53 +++++++++++++++------------------------ 1 file changed, 20 insertions(+), 33 deletions(-) diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c index 5858185211..1ca11e5e9e 100644 --- a/tools/xenstore/xenstored_domain.c +++ b/tools/xenstore/xenstored_domain.c @@ -55,10 +55,6 @@ struct domain repeated domain introductions. */ evtchn_port_t remote_port; - /* The mfn associated with the event channel, used only to validate - repeated domain introductions. */ - unsigned long mfn; - /* Domain path in store. */ char *path; @@ -363,13 +359,12 @@ static void domain_conn_reset(struct domain *domain) domain->interface->rsp_cons = domain->interface->rsp_prod = 0; } -/* domid, mfn, evtchn, path */ +/* domid, gfn, evtchn, path */ int do_introduce(struct connection *conn, struct buffered_data *in) { struct domain *domain; char *vec[3]; unsigned int domid; - unsigned long mfn; evtchn_port_t port; int rc; struct xenstore_domain_interface *interface; @@ -381,7 +376,7 @@ int do_introduce(struct connection *conn, struct buffered_data *in) return EACCES; domid = atoi(vec[0]); - mfn = atol(vec[1]); + /* Ignore the gfn, we don't need it. */ port = atoi(vec[2]); /* Sanity check args. */ @@ -390,34 +385,26 @@ int do_introduce(struct connection *conn, struct buffered_data *in) domain = find_domain_by_domid(domid); - if (domain == NULL) { - interface = map_interface(domid); - if (!interface) - return errno; - /* Hang domain off "in" until we're finished. */ - domain = new_domain(in, domid, port); - if (!domain) { - rc = errno; - unmap_interface(interface); - return rc; - } - domain->interface = interface; - domain->mfn = mfn; - - /* Now domain belongs to its connection. */ - talloc_steal(domain->conn, domain); - - fire_watches(NULL, in, "@introduceDomain", false); - } else if ((domain->mfn == mfn) && (domain->conn != conn)) { - /* Use XS_INTRODUCE for recreating the xenbus event-channel. */ - if (domain->port) - xenevtchn_unbind(xce_handle, domain->port); - rc = xenevtchn_bind_interdomain(xce_handle, domid, port); - domain->port = (rc == -1) ? 0 : rc; - domain->remote_port = port; - } else + if (domain) return EINVAL; + interface = map_interface(domid); + if (!interface) + return errno; + /* Hang domain off "in" until we're finished. */ + domain = new_domain(in, domid, port); + if (!domain) { + rc = errno; + unmap_interface(interface); + return rc; + } + domain->interface = interface; + + /* Now domain belongs to its connection. */ + talloc_steal(domain->conn, domain); + + fire_watches(NULL, in, "@introduceDomain", false); + domain_conn_reset(domain); send_ack(conn, XS_INTRODUCE);