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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 C876AECE564 for ; Wed, 19 Sep 2018 13:34:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 847982151B for ; Wed, 19 Sep 2018 13:34:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 847982151B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731888AbeISTMQ (ORCPT ); Wed, 19 Sep 2018 15:12:16 -0400 Received: from mx2.suse.de ([195.135.220.15]:51744 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727657AbeISTMQ (ORCPT ); Wed, 19 Sep 2018 15:12:16 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 3E9A5ACDE; Wed, 19 Sep 2018 13:34:16 +0000 (UTC) Subject: Re: [PATCH] xen: issue warning message when out of grant maptrack entries To: Boris Ostrovsky , linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org References: <20180918093200.17499-1-jgross@suse.com> <38478db4-2c54-3115-375d-59bfe40b3144@oracle.com> From: Juergen Gross Openpgp: preference=signencrypt Autocrypt: addr=jgross@suse.com; prefer-encrypt=mutual; keydata= xsBNBFOMcBYBCACgGjqjoGvbEouQZw/ToiBg9W98AlM2QHV+iNHsEs7kxWhKMjrioyspZKOB ycWxw3ie3j9uvg9EOB3aN4xiTv4qbnGiTr3oJhkB1gsb6ToJQZ8uxGq2kaV2KL9650I1SJve dYm8Of8Zd621lSmoKOwlNClALZNew72NjJLEzTalU1OdT7/i1TXkH09XSSI8mEQ/ouNcMvIJ NwQpd369y9bfIhWUiVXEK7MlRgUG6MvIj6Y3Am/BBLUVbDa4+gmzDC9ezlZkTZG2t14zWPvx XP3FAp2pkW0xqG7/377qptDmrk42GlSKN4z76ELnLxussxc7I2hx18NUcbP8+uty4bMxABEB AAHNHkp1ZXJnZW4gR3Jvc3MgPGpncm9zc0BzdXNlLmRlPsLAeQQTAQIAIwUCU4xw6wIbAwcL CQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJELDendYovxMvi4UH/Ri+OXlObzqMANruTd4N zmVBAZgx1VW6jLc8JZjQuJPSsd/a+bNr3BZeLV6lu4Pf1Yl2Log129EX1KWYiFFvPbIiq5M5 kOXTO8Eas4CaScCvAZ9jCMQCgK3pFqYgirwTgfwnPtxFxO/F3ZcS8jovza5khkSKL9JGq8Nk czDTruQ/oy0WUHdUr9uwEfiD9yPFOGqp4S6cISuzBMvaAiC5YGdUGXuPZKXLpnGSjkZswUzY d9BVSitRL5ldsQCg6GhDoEAeIhUC4SQnT9SOWkoDOSFRXZ+7+WIBGLiWMd+yKDdRG5RyP/8f 3tgGiB6cyuYfPDRGsELGjUaTUq3H2xZgIPfOwE0EU4xwFgEIAMsx+gDjgzAY4H1hPVXgoLK8 B93sTQFN9oC6tsb46VpxyLPfJ3T1A6Z6MVkLoCejKTJ3K9MUsBZhxIJ0hIyvzwI6aYJsnOew cCiCN7FeKJ/oA1RSUemPGUcIJwQuZlTOiY0OcQ5PFkV5YxMUX1F/aTYXROXgTmSaw0aC1Jpo w7Ss1mg4SIP/tR88/d1+HwkJDVW1RSxC1PWzGizwRv8eauImGdpNnseneO2BNWRXTJumAWDD pYxpGSsGHXuZXTPZqOOZpsHtInFyi5KRHSFyk2Xigzvh3b9WqhbgHHHE4PUVw0I5sIQt8hJq 5nH5dPqz4ITtCL9zjiJsExHuHKN3NZsAEQEAAcLAXwQYAQIACQUCU4xwFgIbDAAKCRCw3p3W KL8TL0P4B/9YWver5uD/y/m0KScK2f3Z3mXJhME23vGBbMNlfwbr+meDMrJZ950CuWWnQ+d+ Ahe0w1X7e3wuLVODzjcReQ/v7b4JD3wwHxe+88tgB9byc0NXzlPJWBaWV01yB2/uefVKryAf AHYEd0gCRhx7eESgNBe3+YqWAQawunMlycsqKa09dBDL1PFRosF708ic9346GLHRc6Vj5SRA UTHnQqLetIOXZm3a2eQ1gpQK9MmruO86Vo93p39bS1mqnLLspVrL4rhoyhsOyh0Hd28QCzpJ wKeHTd0MAWAirmewHXWPco8p1Wg+V+5xfZzuQY0f4tQxvOpXpt4gQ1817GQ5/Ed/wsDtBBgB CAAgFiEEhRJncuj2BJSl0Jf3sN6d1ii/Ey8FAlrd8NACGwIAgQkQsN6d1ii/Ey92IAQZFggA HRYhBFMtsHpB9jjzHji4HoBcYbtP2GO+BQJa3fDQAAoJEIBcYbtP2GO+TYsA/30H/0V6cr/W V+J/FCayg6uNtm3MJLo4rE+o4sdpjjsGAQCooqffpgA+luTT13YZNV62hAnCLKXH9n3+ZAgJ RtAyDWk1B/0SMDVs1wxufMkKC3Q/1D3BYIvBlrTVKdBYXPxngcRoqV2J77lscEvkLNUGsu/z W2pf7+P3mWWlrPMJdlbax00vevyBeqtqNKjHstHatgMZ2W0CFC4hJ3YEetuRBURYPiGzuJXU pAd7a7BdsqWC4o+GTm5tnGrCyD+4gfDSpkOT53S/GNO07YkPkm/8J4OBoFfgSaCnQ1izwgJQ jIpcG2fPCI2/hxf2oqXPYbKr1v4Z1wthmoyUgGN0LPTIm+B5vdY82wI5qe9uN6UOGyTH2B3p hRQUWqCwu2sqkI3LLbTdrnyDZaixT2T0f4tyF5Lfs+Ha8xVMhIyzNb1byDI5FKCb Message-ID: Date: Wed, 19 Sep 2018 15:34:15 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <38478db4-2c54-3115-375d-59bfe40b3144@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/09/18 15:29, Boris Ostrovsky wrote: > On 9/18/18 1:17 PM, Juergen Gross wrote: >> On 18/09/18 19:03, Boris Ostrovsky wrote: >>> On 9/18/18 5:32 AM, Juergen Gross wrote: >>>> When a driver domain (e.g. dom0) is running out of maptrack entries it >>>> can't map any more foreign domain pages. Instead of silently stalling >>>> the affected domUs issue a rate limited warning in this case in order >>>> to make it easier to detect that situation. >>>> >>>> Signed-off-by: Juergen Gross >>>> --- >>>> drivers/xen/grant-table.c | 25 +++++++++++++++++++------ >>>> 1 file changed, 19 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c >>>> index 7bafa703a992..09f6ff8c1957 100644 >>>> --- a/drivers/xen/grant-table.c >>>> +++ b/drivers/xen/grant-table.c >>>> @@ -1040,18 +1040,31 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, >>>> return ret; >>>> >>>> for (i = 0; i < count; i++) { >>>> - /* Retry eagain maps */ >>>> - if (map_ops[i].status == GNTST_eagain) >>>> - gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, >>>> - &map_ops[i].status, __func__); >>>> - >>>> - if (map_ops[i].status == GNTST_okay) { >>>> + switch (map_ops[i].status) { >>>> + case GNTST_okay: >>>> + { >>>> struct xen_page_foreign *foreign; >>>> >>>> SetPageForeign(pages[i]); >>>> foreign = xen_page_foreign(pages[i]); >>>> foreign->domid = map_ops[i].dom; >>>> foreign->gref = map_ops[i].ref; >>>> + break; >>>> + } >>>> + >>>> + case GNTST_no_device_space: >>>> + pr_warn_ratelimited("maptrack limit reached, can't map all guest pages\n"); >>>> + break; >>>> + >>>> + case GNTST_eagain: >>>> + /* Retry eagain maps */ >>>> + gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, >>>> + map_ops + i, >>>> + &map_ops[i].status, __func__); >>>> + break; >>>> + >>>> + default: >>>> + break; >>>> } >>>> } > > > After having a second look at this (and at the risk of embarrassing > myself again with this patch) --- aren't we supposed to test status > after gnttab_retry_eagain_gop() call, and then actually set foreign > properties? Right. Thanks for catching that! V2 coming soon... Juergen