From mboxrd@z Thu Jan 1 00:00:00 1970 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=-10.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 A5CF9C433E6 for ; Fri, 8 Jan 2021 17:53:32 +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 5D6BC23A61 for ; Fri, 8 Jan 2021 17:53:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D6BC23A61 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=cam.ac.uk 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.63782.113122 (Exim 4.92) (envelope-from ) id 1kxvwl-0004hY-9Q; Fri, 08 Jan 2021 17:53:11 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 63782.113122; Fri, 08 Jan 2021 17:53:11 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kxvwl-0004hR-5I; Fri, 08 Jan 2021 17:53:11 +0000 Received: by outflank-mailman (input) for mailman id 63782; Fri, 08 Jan 2021 17:53:09 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kxvwi-0004hL-Qb for xen-devel@lists.xenproject.org; Fri, 08 Jan 2021 17:53:09 +0000 Received: from ppsw-31.csi.cam.ac.uk (unknown [131.111.8.131]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 28b07034-526d-4fa2-8a98-cc692bcfeaa2; Fri, 08 Jan 2021 17:53:07 +0000 (UTC) Received: from 88-111-124-141.dynamic.dsl.as9105.com ([88.111.124.141]:40462 helo=[192.168.1.219]) by ppsw-31.csi.cam.ac.uk (smtp.hermes.cam.ac.uk [131.111.8.157]:465) with esmtpsa (PLAIN:amc96) (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) id 1kxvwZ-000PFX-LH (Exim 4.92.3) (return-path ); Fri, 08 Jan 2021 17:52:59 +0000 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: 28b07034-526d-4fa2-8a98-cc692bcfeaa2 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=cam.ac.uk; s=20180806.ppsw; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=e3bmFR/UoqtFuuF/Sn1ZMjP5hdagzhYKEZ8hIPFmhSY=; b=hyM0sqXMFxcKHkQlOhlerKvIv9 GnZUoFo+FsAmE/7NAG2tCNO6MFFRX8s0WqFu9CdKtGnu92gN1NqSn/q/NdMeJeLrDIj+ce6bbrsM5 AZ58I4FT6picRGFp+rGRGVRE+K9GewBaS8YUWXYemsDIrHBvx+SCwLxLu+Gcq3fWuOuw=; X-Cam-AntiVirus: no malware found X-Cam-ScannerInfo: http://help.uis.cam.ac.uk/email-scanner-virus Subject: Re: [PATCH v2 05/11] tools/foreignmem: Support querying the size of a resource To: Xen-devel Cc: Ian Jackson , =?UTF-8?Q?Micha=c5=82_Leszczy=c5=84ski?= , Hubert Jasudowicz , Tamas K Lengyel , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Andrew Cooper References: <20200922182444.12350-1-andrew.cooper3@citrix.com> <20200922182444.12350-6-andrew.cooper3@citrix.com> From: Andrew Cooper Autocrypt: addr=amc96@cam.ac.uk; keydata= mQINBFLhNn8BEADVhE+Hb8i0GV6mihnnr/uiQQdPF8kUoFzCOPXkf7jQ5sLYeJa0cQi6Penp VtiFYznTairnVsN5J+ujSTIb+OlMSJUWV4opS7WVNnxHbFTPYZVQ3erv7NKc2iVizCRZ2Kxn srM1oPXWRic8BIAdYOKOloF2300SL/bIpeD+x7h3w9B/qez7nOin5NzkxgFoaUeIal12pXSR Q354FKFoy6Vh96gc4VRqte3jw8mPuJQpfws+Pb+swvSf/i1q1+1I4jsRQQh2m6OTADHIqg2E ofTYAEh7R5HfPx0EXoEDMdRjOeKn8+vvkAwhviWXTHlG3R1QkbE5M/oywnZ83udJmi+lxjJ5 YhQ5IzomvJ16H0Bq+TLyVLO/VRksp1VR9HxCzItLNCS8PdpYYz5TC204ViycobYU65WMpzWe LFAGn8jSS25XIpqv0Y9k87dLbctKKA14Ifw2kq5OIVu2FuX+3i446JOa2vpCI9GcjCzi3oHV e00bzYiHMIl0FICrNJU0Kjho8pdo0m2uxkn6SYEpogAy9pnatUlO+erL4LqFUO7GXSdBRbw5 gNt25XTLdSFuZtMxkY3tq8MFss5QnjhehCVPEpE6y9ZjI4XB8ad1G4oBHVGK5LMsvg22PfMJ ISWFSHoF/B5+lHkCKWkFxZ0gZn33ju5n6/FOdEx4B8cMJt+cWwARAQABtB9BbmRyZXcgQ29v cGVyIDxhbWM5NkBjYW0uYWMudWs+iQI4BBMBAgAiBQJYoP3SAhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgAAKCRBlw/kGpdefoOqZEADETHadX+byfQTszP18AjvDxkiOmqKiSBv7JFeB +qW6Egn5mK9rggNQ4ipYm1nST14d+AKlrtCY42oifozzLnfrp2nDS9ViQU87S83QTGGH0CG2 JtpU6IPJihxCaCyoLzMEBav16cfQRKy9KqFID1Nca5sOu4C6kiE1XriEDipEM2LmSqkSrYdP l85fv5WT6rIOBbxi4Gieh79exzaO8a/6yxWL6KvfTlCcMzYQbcfUqYT83mP/P6Dx+E3fkkzF Tb/Cgy9yuYJBAnZ2yCscvbtTILgUWFWqyJ3NNOfZ2LQU0zGvU+H7o5QsaBkNSpz3PTEEd5WB 8I+QMhOdq6hWWU97muoeYd0dkJndKXwRTSsbly7hTxk2wj4cTGgTw/UiBlHPL26KGXSGI5XM Y1flNmJQBF8xy4jxkPpvaMsi5A2YU8DV0Qm9RoKYGuEKJO8zAgzJgvgVO7Kbcdv/nLLevpp0 uPZTeWygCMr6YfBcS/r8E/qbBso7KzlxrpscCbXnJwIDmdWUvrFkP06sSsjkdS3D37yOGXkB DX31FdOo+vbnpoWI0meZsAGl9/wZ72GoaYxvDWcQSy85+qH4T342FRA2B6Br5/7r3D2bvlNJ i5DLu08dnE4KR6g3C3t1Hm0oIYJ31MtSe2RHA7ieEiJnmXsWfzAJMFPZLnVQ3yGWcontq7kC DQRS4TZ/ARAAkgqudHsp+hd82UVkvgnlqZjzz2vyrYfz7bkPtXaGb9H4Rfo7mQsEQavEBdWW jbga6eMnDqtu+FC+qeTGYebToxEyp2lKDSoAsvt8w82tIlP/EbmRbDVn7bhjBlfRcFjVYw8u VDPptT0TV47vpoCVkTwcyb6OltJrvg/QzV9f07DJswuda1JH3/qvYu0pvjPnYvCq4NsqY2XS dAJ02HrdYPFtNyPEntu1n1KK+gJrstjtw7KsZ4ygXYrsm/oCBiVW/OgUg/XIlGErkrxe4vQv JyVwg6YH653YTX5hLLUEL1NS4TCo47RP+wi6y+TnuAL36UtK/uFyEuPywwrDVcC4cIFhYSfs O0BumEI65yu7a8aHbGfq2lW251UcoU48Z27ZUUZd2Dr6O/n8poQHbaTd6bJJSjzGGHZVbRP9 UQ3lkmkmc0+XCHmj5WhwNNYjgbbmML7y0fsJT5RgvefAIFfHBg7fTY/ikBEimoUsTEQz+N4h bKwo1hULfVxDJStE4sbPhjbsPCrlXf6W9CxSyQ0qmZ2bXsLQYRj2xqd1bpA+1o1j2N4/au1R /uSiUFjewJdT/LX1EklKDcQwpk06Af/N7VZtSfEJeRV04unbsKVXWZAkuAJyDDKN99ziC0Wz 5kcPyVD1HNf8bgaqGDzrv3TfYjwqayRFcMf7xJaL9xXedMcAEQEAAYkCHwQYAQgACQUCUuE2 fwIbDAAKCRBlw/kGpdefoG4XEACD1Qf/er8EA7g23HMxYWd3FXHThrVQHgiGdk5Yh632vjOm 9L4sd/GCEACVQKjsu98e8o3ysitFlznEns5EAAXEbITrgKWXDDUWGYxdpnjj2u+GkVdsOAGk 0kxczX6s+VRBhpbBI2PWnOsRJgU2n10PZ3mZD4Xu9kU2IXYmuW+e5KCAvTArRUdCrAtIa1k0 1sPipPPw6dfxx2e5asy21YOytzxuWFfJTGnVxZZSCyLUO83sh6OZhJkkb9rxL9wPmpN/t2IP aEKoAc0FTQZS36wAMOXkBh24PQ9gaLJvfPKpNzGD8XWR5HHF0NLIJhgg4ZlEXQ2fVp3Xrtoc Hqhu4UZR4koCijgB8sB7Tb0GCpwK+C4UePdFLfhKyRdSXuvY3AHJd4CP4JzW0Bzq/WXY3XMO zUTYApGQpnUpdOmuQSfpV9MQO+/jo7r6yPbxT7CwRS5dcQPzUiuHLK9invjREdh84qycnx0/ 6dDroYhp0DFv4udxuAvt1h4wGwTPRQZerSm4xaYegEFusyhbZrI0U9tJB8WrhBLXDiYlyJT6 zOV2yZFuW47VrLsjYnHwn27hmxTC/7tvG3euCklmkn9Sl9IAKFu29RSod5bD8kMSCYsTqtTf T6W4A3qHGvIDta3ptLYpIAOD2sY3GYq2nf3Bbzx81wZK14JdDDHUX2Rs6+ahAA== Message-ID: <22be067c-1e6f-c87d-f910-ced27091a87a@cam.ac.uk> Date: Fri, 8 Jan 2021 17:52:36 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200922182444.12350-6-andrew.cooper3@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-GB On 22/09/2020 19:24, Andrew Cooper wrote: > diff --git a/tools/libs/foreignmemory/linux.c b/tools/libs/foreignmemory/linux.c > index fe73d5ab72..eec089e232 100644 > --- a/tools/libs/foreignmemory/linux.c > +++ b/tools/libs/foreignmemory/linux.c > @@ -339,6 +342,39 @@ int osdep_xenforeignmemory_map_resource( > return 0; > } > > +int osdep_xenforeignmemory_resource_size( > + xenforeignmemory_handle *fmem, domid_t domid, unsigned int type, > + unsigned int id, unsigned long *nr_frames) > +{ > + int rc; > + struct xen_mem_acquire_resource *xmar = > + xencall_alloc_buffer(fmem->xcall, sizeof(*xmar)); > + > + if ( !xmar ) > + { > + PERROR("Could not bounce memory for acquire_resource hypercall"); > + return -1; > + } > + > + *xmar = (struct xen_mem_acquire_resource){ > + .domid = domid, > + .type = type, > + .id = id, > + }; > + > + rc = xencall2(fmem->xcall, __HYPERVISOR_memory_op, > + XENMEM_acquire_resource, (uintptr_t)xmar); > + if ( rc ) > + goto out; > + > + *nr_frames = xmar->nr_frames; > + > + out: > + xencall_free_buffer(fmem->xcall, xmar); > + > + return rc; > +} Having talked this through with Roger, it's broken. In the meantime, foreignmem has gained acquire_resource on FreeBSD. Nothing in this osdep function is linux-specific, so it oughtn't to be osdep. However, its also not permitted to make hypercalls like this in restricted mode, and that isn't something we should be breaking.  Amongst other things, it will prevent us from supporting >128 cpus, as Qemu needs updating to use this interface in due course. The only solution (which keeps restricted mode working) is to fix Linux's ioctl() to be able to understand size requests.  This also avoids foreignmem needing to open a xencall handle which was fugly in the first place. This patch (well - a subset of it) will be needed to remain, to make a usable interface in userspace. ~Andrew