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.gnu.org (lists.gnu.org [209.51.188.17]) (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 B9935EB64DC for ; Mon, 17 Jul 2023 16:30:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qLR72-0005KC-33; Mon, 17 Jul 2023 12:30:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qLR6s-0005Jz-DU for qemu-devel@nongnu.org; Mon, 17 Jul 2023 12:30:06 -0400 Received: from mail-ot1-x329.google.com ([2607:f8b0:4864:20::329]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qLR6p-0001Xn-Le for qemu-devel@nongnu.org; Mon, 17 Jul 2023 12:30:06 -0400 Received: by mail-ot1-x329.google.com with SMTP id 46e09a7af769-6b9defb366eso290653a34.2 for ; Mon, 17 Jul 2023 09:30:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1689611402; x=1692203402; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=kzumRxpe7OV4cHt2z4WaE55tMoB7SFnfq9lmJz7W1vo=; b=NKxKDSGtHRWZwBbgzINmZdynJueKEKzf5VST8+/rbiR/fGHIOFSzjqvBLz/I+HbD2F xJaTPXduNz2FnJLIh9j1CHlDYAQDw2YmieVeJTjXFIhFgofCODd2OHPGegsaEB4+bgyJ K7xsrbrzeoPF1FiZeH3ogn9cXH9uAEOzonaM4nNLSJAaYaZgj107KKNzlr5nMNmT6S3O rTrowM/fkvY0N4jL0jua0HasXYbGYumd2s6DxmWsAKSjSrzFPDJu+yJ/8CtH874t13QP 1H9xa85G10JHCc/NzFYzCaF6a0kWyEhofGA16eDy7hhmCr9bu8C+/+3p1n8ntLkl4kPy jW9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689611402; x=1692203402; h=content-transfer-encoding:in-reply-to: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=kzumRxpe7OV4cHt2z4WaE55tMoB7SFnfq9lmJz7W1vo=; b=SJQ1gV5AemtefS/kiH04HjEIDuOxV9q3+sFHCwF3kwb2nxzroPfVBsWZ1GTQWr4WBA +duuWThsxVsJC324qRjGa22x+dLNor63/x1yQMUm7eSVKDMvMKsk4X78Ig73QNEkLdrJ 0dlQvCpa4XKgQyh9p5e8dSHGiEdKuVD/1KMK07nkZL99NKmey05bbQ19SWZV1Ew42z7T 0b79YOrj8SD1sMjk5b++L1qt4CObODNsMF/wVPXg3Ax42n3RD15efwAdSgUqf0r+LyQf q447bs19vwudJwIBv+JkrPwJByMaoegLi1gJHerEGOdW2FgNViW2LN4YQ3IHaI9zFv+7 V3Fw== X-Gm-Message-State: ABy/qLYU2V0bNRph5Sk6tYk497Z+MBPfcXxWDL5RiVRPJvOJR1Mvdr6x mEi5a9PBTlo6ELUtN50Q43M= X-Google-Smtp-Source: APBJJlEQiDDyvzF3EohCfBvriE9W7YTQqLJaTkex5XN2wPstS1eRPas5SJ2q63uKJtbwiEmG8nUSCg== X-Received: by 2002:a05:6830:138b:b0:6b1:5f4a:f52d with SMTP id d11-20020a056830138b00b006b15f4af52dmr11200519otq.22.1689611401888; Mon, 17 Jul 2023 09:30:01 -0700 (PDT) Received: from ?IPV6:2001:ee0:4fb3:b780:92a3:418a:c0a9:6803? ([2001:ee0:4fb3:b780:92a3:418a:c0a9:6803]) by smtp.gmail.com with ESMTPSA id s11-20020a63b40b000000b0055fe64fd3f4sm32640pgf.9.2023.07.17.09.29.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 Jul 2023 09:30:01 -0700 (PDT) Message-ID: Date: Mon, 17 Jul 2023 23:29:56 +0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH v6 4/5] intel_iommu: allow Extended Interrupt Mode when using userspace APIC To: Joao Martins Cc: David Woodhouse , Paolo Bonzini , Richard Henderson , Eduardo Habkost , "Michael S . Tsirkin" , Marcel Apfelbaum , Igor Mammedov , =?UTF-8?Q?Alex_Benn=c3=a9e?= , qemu-devel@nongnu.org, Peter Xu , Jason Wang References: <20230715152224.54757-1-minhquangbui99@gmail.com> <20230715152224.54757-5-minhquangbui99@gmail.com> <4f5a644e-8341-798a-bfe3-27eeb5816623@oracle.com> Content-Language: en-US From: Bui Quang Minh In-Reply-To: <4f5a644e-8341-798a-bfe3-27eeb5816623@oracle.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::329; envelope-from=minhquangbui99@gmail.com; helo=mail-ot1-x329.google.com X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, NICE_REPLY_A=-0.097, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 7/17/23 17:47, Joao Martins wrote: > +Peter, +Jason (intel-iommu maintainer/reviewer) > > On 15/07/2023 16:22, Bui Quang Minh wrote: >> As userspace APIC now supports x2APIC, intel interrupt remapping >> hardware can be set to EIM mode when userspace local APIC is used. >> >> Reviewed-by: Michael S. Tsirkin >> Signed-off-by: Bui Quang Minh >> --- >> hw/i386/intel_iommu.c | 11 ----------- >> 1 file changed, 11 deletions(-) >> >> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c >> index dcc334060c..5e576f6059 100644 >> --- a/hw/i386/intel_iommu.c >> +++ b/hw/i386/intel_iommu.c >> @@ -4043,17 +4043,6 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error **errp) >> && x86_iommu_ir_supported(x86_iommu) ? >> ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF; >> } >> - if (s->intr_eim == ON_OFF_AUTO_ON && !s->buggy_eim) { >> - if (!kvm_irqchip_is_split()) { >> - error_setg(errp, "eim=on requires accel=kvm,kernel-irqchip=split"); >> - return false; >> - } >> - if (!kvm_enable_x2apic()) { >> - error_setg(errp, "eim=on requires support on the KVM side" >> - "(X2APIC_API, first shipped in v4.7)"); >> - return false; >> - } >> - } >> > Given commit 20ca47429e ('Revert "intel_iommu: Fix irqchip / X2APIC > configuration checks"'), won't we regress behaviour again for the accel=kvm > case by dropping the kvm_enable_x2apic() call here? > > Perhaps if we support userspace APIC with TCG the check just needs to be redone > to instead avoid always requiring kvm e.g.: > > if (kvm_irqchip_in_kernel()) { > error_setg(errp, "eim=on requires accel=kvm,kernel-irqchip=split" > "(X2APIC_API, first shipped in v4.7)"); > } > > if (kvm_irqchip_is_split() && !kvm_enable_x2apic()) { > error_setg(errp, "eim=on requires support on the KVM side" > "(X2APIC_API, first shipped in v4.7)"); > return false; > } Thank you for your review. I think the check for kvm_irqchip_in_kernel() is not correct, AFAIK, kvm_irqchip_is_split() == true also means kvm_irqchip_in_kernel() == true on x86. To check if kernel-irqchip = on, we need to do something like in x86_iommu_realize bool irq_all_kernel = kvm_irqchip_in_kernel() && !kvm_irqchip_is_split(); The original check for !kvm_irqchip_is_split means emulated/userspace APIC. It's because to reach that check x86_iommu_ir_supported(...) == true and x86_iommu_ir_supported(...) == true is not supported when kernel-irqchip = on (there is a check for this in x86_iommu_realize) So I think we need to change the check to if (s->intr_eim == ON_OFF_AUTO_ON && !s->buggy_eim) { if (kvm_irqchip_is_split() && !kvm_enable_x2apic()) { error_setg(errp, "eim=on requires support on the KVM side" "(X2APIC_API, first shipped in v4.7)"); return false; } } Is it OK? Thanks, Quang Minh.