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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D22D4C27C53 for ; Wed, 12 Jun 2024 09:21:55 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.739052.1145963 (Exim 4.92) (envelope-from ) id 1sHKAr-00068p-RM; Wed, 12 Jun 2024 09:21:45 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 739052.1145963; Wed, 12 Jun 2024 09:21:45 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sHKAr-00068i-Om; Wed, 12 Jun 2024 09:21:45 +0000 Received: by outflank-mailman (input) for mailman id 739052; Wed, 12 Jun 2024 09:21:44 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sHKAq-00068T-LS for xen-devel@lists.xenproject.org; Wed, 12 Jun 2024 09:21:44 +0000 Received: from mail-ed1-x536.google.com (mail-ed1-x536.google.com [2a00:1450:4864:20::536]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 2f23a1c8-289d-11ef-90a3-e314d9c70b13; Wed, 12 Jun 2024 11:21:43 +0200 (CEST) Received: by mail-ed1-x536.google.com with SMTP id 4fb4d7f45d1cf-57c68682d1aso4940754a12.3 for ; Wed, 12 Jun 2024 02:21:43 -0700 (PDT) Received: from [10.156.60.236] (ip-037-024-206-209.um08.pools.vodafone-ip.de. [37.24.206.209]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a6ef441b3d6sm662162566b.203.2024.06.12.02.21.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 12 Jun 2024 02:21:43 -0700 (PDT) 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: 2f23a1c8-289d-11ef-90a3-e314d9c70b13 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1718184103; x=1718788903; darn=lists.xenproject.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=0hXpePDv78pKPWRABOaJqWPezG+KTeK8tT5jZ5ivkqw=; b=DbAV2o6h46cftDNhJoflhw/ytwR2LRNa107SwIZADJOCsTKWKJAs17fnYVXiQPohzE rCK3n1ITnBLY/U2vgEQi4uMNpndz4CD29dFhFdLSFIgMs33RZdfAHotId9e5khMOWT45 Y11tzPsA4o3uARGV5JKz+v+CtD7IHqqFwbIMe9AOyznzfeQh6RII1lQWj64aaV99x2Ez +EUUksNlGqv9ZAAXBkslsvwHTaxH1HTOIFTUhnkG0CsH5Wf0y82DwLjUArV/vmVXnuVt 9Ywh9WkP323feQgApbBf7JaoE0RQaoyiTnRrw8O+Ulwd0IVlyrREpU7+3c0O7qZ7cAo8 pcVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718184103; x=1718788903; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=0hXpePDv78pKPWRABOaJqWPezG+KTeK8tT5jZ5ivkqw=; b=tHWjede2zHmiu+Ey/JXzBf0LVmRPW4d34Sx40RzOlJEuTiiJMGcXC+Kg/6t8t6Y9hf NFMqNnh2lDpSNu526ZcR7bE5njRCeT5v+wiFn0hXNxovDaqHYAy92/m8XzSVEQarfNbJ i/A7WSaDSTF+mEoRBvK9IPp14ATSgXA1iguJq3Rj36ygCMI+1pckVvRe53OyaCf1DDUL slue8qw5C2Ucov46ziwvf4VSenJ86BsNzP7IA3upcagVJG2FhXAN8M5a7sw14JilpEKL gBiWEV148Bz7Q55pduwvsjam6o3kfMi6tDzblGTQdunTBJBcFIEN3jCt7THGS6aDTHZG /gew== X-Forwarded-Encrypted: i=1; AJvYcCX7gpUqw+Gyhk2Tavh20gw0Cqwemyhn8NoFYb7KadKOxnQ4Z+MmHU9kqe+DvzlCq84yTGn90UMqIu09fwtVqDnhh2rytWKXJWA4SIRYZ+8= X-Gm-Message-State: AOJu0YxwXWyN5suo23mJaam3PMfgboDGML2yGSIAZ3UnKGbj25uBIn8A 5TUo2DCx3fykrTCEMJ8MzIX6tntxGbISGG6jdn/N/PNpz2ziaTlN3wwALqhhjA== X-Google-Smtp-Source: AGHT+IFlBMLpFH8pD3tYHVMvpo5ztndrbzGLUqq3GPQlUaPbMwENZBudPm+MyvCT5AXk2yUM7mgcig== X-Received: by 2002:a17:907:7e91:b0:a6f:1400:2e13 with SMTP id a640c23a62f3a-a6f47fd6f50mr87537566b.58.1718184103243; Wed, 12 Jun 2024 02:21:43 -0700 (PDT) Message-ID: <5bb436a7-d426-4413-84bf-907615e12212@suse.com> Date: Wed, 12 Jun 2024 11:21:41 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [XEN PATCH v9 2/5] x86/pvh: Allow (un)map_pirq when dom0 is PVH To: "Chen, Jiqian" Cc: Andrew Cooper , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Wei Liu , George Dunlap , Julien Grall , Stefano Stabellini , Anthony PERARD , Juergen Gross , "Daniel P . Smith" , "Hildebrand, Stewart" , "Huang, Ray" , "xen-devel@lists.xenproject.org" References: <20240607081127.126593-1-Jiqian.Chen@amd.com> <20240607081127.126593-3-Jiqian.Chen@amd.com> <41905257-e2e6-4bce-b723-516916448dfd@suse.com> Content-Language: en-US From: Jan Beulich Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 12.06.2024 11:07, Chen, Jiqian wrote: > On 2024/6/12 16:53, Jan Beulich wrote: >> On 12.06.2024 04:43, Chen, Jiqian wrote: >>> On 2024/6/10 23:58, Jan Beulich wrote: >>>> On 07.06.2024 10:11, Jiqian Chen wrote: >>>>> If run Xen with PVH dom0 and hvm domU, hvm will map a pirq for >>>>> a passthrough device by using gsi, see qemu code >>>>> xen_pt_realize->xc_physdev_map_pirq and libxl code >>>>> pci_add_dm_done->xc_physdev_map_pirq. Then xc_physdev_map_pirq >>>>> will call into Xen, but in hvm_physdev_op, PHYSDEVOP_map_pirq >>>>> is not allowed because currd is PVH dom0 and PVH has no >>>>> X86_EMU_USE_PIRQ flag, it will fail at has_pirq check. >>>>> >>>>> So, allow PHYSDEVOP_map_pirq when dom0 is PVH and also allow >>>>> PHYSDEVOP_unmap_pirq for the failed path to unmap pirq. And >>>>> add a new check to prevent self map when subject domain has no >>>>> PIRQ flag. >>>>> >>>>> Signed-off-by: Huang Rui >>>>> Signed-off-by: Jiqian Chen >>>>> Reviewed-by: Stefano Stabellini >>>> >>>> What's imo missing in the description is a clarification / justification of >>>> why it is going to be a good idea (or at least an acceptable one) to expose >>>> the concept of PIRQs to PVH. If I'm not mistaken that concept so far has >>>> been entirely a PV one. >>> I didn't want to expose the concept of PIRQs to PVH. >>> I did this patch is for HVM that use PIRQs, what I said in commit message is HVM will map a pirq for gsi, not PVH. >>> For the original code, it checks " !has_pirq(currd)", but currd is PVH dom0, so it failed. So I need to allow PHYSDEVOP_map_pirq >>> even currd has no PIRQs, but the subject domain has. >> >> But that's not what you're enforcing in do_physdev_op(). There you only >> prevent self-mapping. If I'm not mistaken all you need to do is drop the >> "d == current->domain" checks from those conditionals. > What I want is to allow PHYSDEVOP_map_pirq when currd doesn't have PIRQs, but subject domain has. > Then I just add "break" in hvm_physdev_op without any checks, that will cause self-mapping problems. > And in previous mail thread, you suggested me to prevent self-mapping when subject domain doesn't have PIRQs. > So I added checks in do_physdev_op. Self-mapping was a primary concern of mine. Yet why deal with only a subset of what needs preventing, when generalizing things actually can be done by having less code. Jan