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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 220DDC433EF for ; Wed, 10 Nov 2021 14:03:35 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id B56A2610CF for ; Wed, 10 Nov 2021 14:03:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B56A2610CF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:40186 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mkoCL-0001K2-6p for qemu-devel@archiver.kernel.org; Wed, 10 Nov 2021 09:03:33 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40798) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mko76-0001km-3D for qemu-devel@nongnu.org; Wed, 10 Nov 2021 08:58:08 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:30611) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mko73-0007Rp-Op for qemu-devel@nongnu.org; Wed, 10 Nov 2021 08:58:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1636552685; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rlklEYnq5aXOWPWC24ZVE+J2xncWIZY0bymgCLCCRTk=; b=Pv3euuSzjwhqEvHZMi8FU57pqdWI9I2UzWpPXFxE/QgUtib4cecv49gKo7XEYHwD9x+SUI kYFGJFO2c9/9YFUjDl1pvtW5S/zDil83N9MGq6zfB1lTsuS2oFhaW07kFUW0S3e8Rh1SBf FO8Gm/bzV6CYjSnz9dAMbSreGe1FexA= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-491-uJGM_vEYM5i8nCtcbSyZ_Q-1; Wed, 10 Nov 2021 08:58:03 -0500 X-MC-Unique: uJGM_vEYM5i8nCtcbSyZ_Q-1 Received: by mail-wm1-f70.google.com with SMTP id g80-20020a1c2053000000b003331a764709so3146638wmg.2 for ; Wed, 10 Nov 2021 05:58:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rlklEYnq5aXOWPWC24ZVE+J2xncWIZY0bymgCLCCRTk=; b=Z5emQxeBIcPJeOofpKXumEHxerQiV6PyuEW4WI7zIf7EgJPbh6TLTf4ZUA+nNiXRRH figt2MW+wuKAWboqh1ukgmBWnjlIc+LNTHyDj+zGIKPc8KvAD5TtqjTCoNwcbup3I03F W7xm5aRYrdAnpONJnhUKxZseVwjdXlorSmXSglz1c4p996eP6kWKWm2lbZR70g5/AjxU zt6XJF1ZizsXFD25C0ftsWf5Fm6t645rZQxa7LJ33+AYjVoH5z5LMPgmzKuD1nX3FqrS NR0K+R1yTG8ffiGnlClZ7lIbJFJK7HOOp2bzfPQu/YekrEZL0bghXAhRjHC+TxvZlyyV yoCg== X-Gm-Message-State: AOAM533gz9Dz2qrKZpkRcXCxXx+gFY/O09NDdWPc0ooBxUb1CVyXawtY iYjWNvwFLy5m4F2OJRDyMjGHgyH5JEPW11PjhucVPLi4cbmpAhFeEf2ecEcAAiP9vJXmSjSX9iF Lf4aO0Fx3v3iMXgE= X-Received: by 2002:a5d:69ce:: with SMTP id s14mr19684881wrw.25.1636552682594; Wed, 10 Nov 2021 05:58:02 -0800 (PST) X-Google-Smtp-Source: ABdhPJyY0PfDKuExVMSeZ7lphA6ZW2CZuHu76jnggbKdOeea7fPGewVBVN4Zb4f86fGK2Ptm0wjCAQ== X-Received: by 2002:a5d:69ce:: with SMTP id s14mr19684852wrw.25.1636552682349; Wed, 10 Nov 2021 05:58:02 -0800 (PST) Received: from localhost ([185.140.112.229]) by smtp.gmail.com with ESMTPSA id u2sm22117867wrr.35.2021.11.10.05.58.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Nov 2021 05:58:01 -0800 (PST) Date: Wed, 10 Nov 2021 14:57:59 +0100 From: Igor Mammedov To: "Michael S. Tsirkin" Subject: Re: [PATCH 4/5] hw/i386/acpi-build: Deny control on PCIe Native Hot-plug in _OSC Message-ID: <20211110145759.6570170e@redhat.com> In-Reply-To: <20211110011557-mutt-send-email-mst@kernel.org> References: <20211110053014.489591-1-jusual@redhat.com> <20211110053014.489591-5-jusual@redhat.com> <20211110011557-mutt-send-email-mst@kernel.org> X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=imammedo@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=imammedo@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.699, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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: , Cc: Ani Sinha , Marcel Apfelbaum , Julia Suvorova , qemu-devel@nongnu.org, Gerd Hoffmann Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 10 Nov 2021 02:21:34 -0500 "Michael S. Tsirkin" wrote: > On Wed, Nov 10, 2021 at 06:30:13AM +0100, Julia Suvorova wrote: > > There are two ways to enable ACPI PCI Hot-plug: > > > > * Disable the Hot-plug Capable bit on PCIe slots. > > > > This was the first approach which led to regression [1-2], as > > I/O space for a port is allocated only when it is hot-pluggable, > > which is determined by HPC bit. > > > > * Leave the HPC bit on and disable PCIe Native Hot-plug in _OSC > > method. > > > > This removes the (future) ability of hot-plugging switches with PCIe > > Native hotplug since ACPI PCI Hot-plug only works with cold-plugged > > bridges. If the user wants to explicitely use this feature, they can > > disable ACPI PCI Hot-plug with: > > --global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off > > > > Change the bit in _OSC method so that the OS selects ACPI PCI Hot-plug > > instead of PCIe Native. > > > > [1] https://gitlab.com/qemu-project/qemu/-/issues/641 > > [2] https://bugzilla.redhat.com/show_bug.cgi?id=2006409 > > > > Signed-off-by: Julia Suvorova > > --- > > hw/i386/acpi-build.c | 12 ++++++++---- > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > > index a3ad6abd33..a2f92ab32b 100644 > > --- a/hw/i386/acpi-build.c > > +++ b/hw/i386/acpi-build.c > > @@ -1337,7 +1337,7 @@ static void build_x86_acpi_pci_hotplug(Aml *table, uint64_t pcihp_addr) > > aml_append(table, scope); > > } > > > > -static Aml *build_q35_osc_method(void) > > +static Aml *build_q35_osc_method(bool acpi_pcihp) > > { > > Aml *if_ctx; > > Aml *if_ctx2; > > @@ -1345,6 +1345,7 @@ static Aml *build_q35_osc_method(void) > > Aml *method; > > Aml *a_cwd1 = aml_name("CDW1"); > > Aml *a_ctrl = aml_local(0); > > + const uint64_t hotplug = acpi_pcihp ? 0x1E : 0x1F; > > drop this variable and open-code at use point below. > As it is the comment is misplaced. > Also a slightly better way to write this: > 0x1E | (acpi_pcihp ? 0x0 : 0x1) > > > > > > > method = aml_method("_OSC", 4, AML_NOTSERIALIZED); > > aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1")); > > So what acpi_pcihp does is enable/disable native pcie hotplug. > How about we call the option exactly that? > > > > @@ -1359,8 +1360,9 @@ static Aml *build_q35_osc_method(void) > > /* > > * Always allow native PME, AER (no dependencies) > > * Allow SHPC (PCI bridges can have SHPC controller) > > + * Disable PCIe Native Hot-plug if ACPI PCI Hot-plug is enabled. > > */ > > - aml_append(if_ctx, aml_and(a_ctrl, aml_int(0x1F), a_ctrl)); > > + aml_append(if_ctx, aml_and(a_ctrl, aml_int(hotplug), a_ctrl)); > > > > using the variable hotplug just made things confusing, > open-coding will be clearer. > > > > if_ctx2 = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(1)))); > > /* Unknown revision */ > > @@ -1449,7 +1451,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, > > aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03"))); > > aml_append(dev, aml_name_decl("_ADR", aml_int(0))); > > aml_append(dev, aml_name_decl("_UID", aml_int(pcmc->pci_root_uid))); > > - aml_append(dev, build_q35_osc_method()); > > + aml_append(dev, build_q35_osc_method(pm->pcihp_bridge_en)); > > aml_append(sb_scope, dev); > > if (mcfg_valid) { > > aml_append(sb_scope, build_q35_dram_controller(&mcfg)); > > One of the complaints of libvirt people was that the > name is confusing. It seems to say whether to describe bridges > in ACPI but it also disables native hotplug, but only for PCIe. > > Maybe we should address this with flags saying whether to enable each of > acpi,pcie,shpc hotplug separately... yep, mask with field defines would be better, but I'd hold off such change to post 6.2 time. > > > @@ -1565,7 +1567,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, > > if (pci_bus_is_express(bus)) { > > aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A08"))); > > aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03"))); > > - aml_append(dev, build_q35_osc_method()); > > + /* Expander bridges do not have ACPI PCI Hot-plug enabled */ > > + aml_append(dev, build_q35_osc_method(false)); this's it not obvious, why PXBs aren't capable of ACPI PCI Hot-plug? > > } else { > > aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03"))); > > } > > -- > > 2.31.1 >