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 1BA64C6FD1D for ; Tue, 14 Mar 2023 13:17:07 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.509590.785612 (Exim 4.92) (envelope-from ) id 1pc4WK-0007WJ-QJ; Tue, 14 Mar 2023 13:16:52 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 509590.785612; Tue, 14 Mar 2023 13:16:52 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pc4WK-0007WC-Nb; Tue, 14 Mar 2023 13:16:52 +0000 Received: by outflank-mailman (input) for mailman id 509590; Tue, 14 Mar 2023 13:16:51 +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 1pc4WJ-0007W4-IK for xen-devel@lists.xenproject.org; Tue, 14 Mar 2023 13:16:51 +0000 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 793455f9-c26a-11ed-87f5-c1b5be75604c; Tue, 14 Mar 2023 14:16:49 +0100 (CET) Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-648-mcfBmHJ9PrOvMrkb81M5ng-1; Tue, 14 Mar 2023 09:16:46 -0400 Received: by mail-ed1-f71.google.com with SMTP id b7-20020a056402350700b004d2a3d5cd3fso21742557edd.8 for ; Tue, 14 Mar 2023 06:16:45 -0700 (PDT) Received: from redhat.com ([2a02:14f:1f7:4129:3ef9:ea05:f0ca:6b81]) by smtp.gmail.com with ESMTPSA id r8-20020a170906c28800b00928e0ea53e5sm1138289ejz.84.2023.03.14.06.16.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Mar 2023 06:16:42 -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: 793455f9-c26a-11ed-87f5-c1b5be75604c DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678799807; 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: in-reply-to:in-reply-to:references:references; bh=hIAXseRKi4A6hgBwN93vaPfaXQdoWyfyU0Q1ZAsvdyE=; b=GV9b9xfCzHHlET54GemQxQj8R2yuonHA2HWNEgw5ZFKUjW8WYqOeX0Tixsb5tvRZViKnn6 sCHFJ0SFUYRusjrfrN+FllXywReG7v+M/7tAOPIcqy1br6GiWD+4w+AsYcIhOzVSbC4EJq 6dVPoxO6rTS+7r0VrWqcVD7RqwNc3kw= X-MC-Unique: mcfBmHJ9PrOvMrkb81M5ng-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678799803; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=hIAXseRKi4A6hgBwN93vaPfaXQdoWyfyU0Q1ZAsvdyE=; b=1alC9XDPQb1w1S7zsJLC/vae/GY0dWm5iVS/GN2W03tiLWOvD1f4VIe4rhlajWM9hN r05LZL1zTLkusrrqo6Xm8apy6NoDGXly7tBH2El1ywOsihu5GlPpWbq0dH++RmiLc+9i f5NXZsm4FozSxfmSVdHqvP2fdyeKkeeHeXV4WhNroqFRxAP6NRzok1+Vr4ZSwh5/Y4rU Oz/55wUWZWBSmkJxv+2GsmfMYXnVoIMVpmM8RaUprT27fiVl5u3EXsoqMh4bN31SBtar JtGNo9X6DAO3D4v2lNQrHrbmT+wn1rSpOL0+ZitpaUMr7ScPPxhehhJtJapeftVVQFT9 undg== X-Gm-Message-State: AO0yUKW2bzkNEtOVtjpn/L87ooZwvUVXWcwOmlZ8RcmUkXcZXI7RlI7m oB60ik8C5UwU1eG4sLuN4n2esKZvlYHZ1ARRJ9hKKi9lthNXQvmXi9UVgM5K9fe6lylAEc78udI /OlBhH+l/N5rlpXO55Cg6WeYO4Hc= X-Received: by 2002:a17:907:d13:b0:8f4:809e:faee with SMTP id gn19-20020a1709070d1300b008f4809efaeemr2766641ejc.19.1678799803059; Tue, 14 Mar 2023 06:16:43 -0700 (PDT) X-Google-Smtp-Source: AK7set/bTtWokPnmCG+Y9HcT9FaE2j2zBWfT9dGSuyKJ37cXmbtLNdihy9mpTH9ckpsrrBBKuM8Gcw== X-Received: by 2002:a17:907:d13:b0:8f4:809e:faee with SMTP id gn19-20020a1709070d1300b008f4809efaeemr2766612ejc.19.1678799802743; Tue, 14 Mar 2023 06:16:42 -0700 (PDT) Date: Tue, 14 Mar 2023 09:16:36 -0400 From: "Michael S. Tsirkin" To: Chuck Zmudzinski Cc: qemu-devel@nongnu.org, Marcel Apfelbaum , Mark Cave-Ayland , Artyom Tarasenko , Stefano Stabellini , Anthony Perard , Paul Durrant , xen-devel@lists.xenproject.org Subject: Re: [PATCH v2 2/2] pci: allow slot_reserved_mask to be ignored with manual slot assignment Message-ID: <20230314091342-mutt-send-email-mst@kernel.org> References: <20230314023148-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Mar 14, 2023 at 08:33:02AM -0400, Chuck Zmudzinski wrote: > On 3/14/2023 2:33 AM, Michael S. Tsirkin wrote: > > On Tue, Mar 14, 2023 at 12:01:09AM -0400, Chuck Zmudzinski wrote: > > > Commit 4f67543bb8c5 ("xen/pt: reserve PCI slot 2 for Intel igd-passthru") > > > uses slot_reserved_mask to reserve slot 2 for the Intel IGD for the > > > xenfv machine when the guest is configured for igd-passthru. > > > > > > A desired extension to that commit is to allow use of the reserved slot > > > if the administrator manually configures a device to use the reserved > > > slot. Currently, slot_reserved_mask is enforced unconditionally. With > > > this patch, the pci bus can be configured so the slot is only reserved > > > if the pci device to be added to the bus is configured for automatic > > > slot assignment. > > > > > > To enable the desired behavior of slot_reserved_mask machine, add a > > > boolean member enforce_slot_reserved_mask_manual to struct PCIBus and > > > add a function pci_bus_ignore_slot_reserved_mask_manual which can be > > > called to change the default behavior of always enforcing > > > slot_reserved_mask so, in that case, slot_reserved_mask is only enforced > > > when the pci device being added is configured for automatic slot > > > assignment. > > > > > > Call the new pci_bus_ignore_slot_reserved_mask_manual function after > > > creating the pci bus for the pc/i440fx/xenfv machine type to implement > > > the desired behavior of causing slot_reserved_mask to only apply when > > > the pci device to be added to a pc/i440fx/xenfv machine is configured > > > for automatic slot assignment. > > > > > > Link: https://lore.kernel.org/qemu-devel/20230106064838-mutt-send-email-mst@kernel.org/ > > > Signed-off-by: Chuck Zmudzinski > > > > I really dislike this. > > It seems that xen should not have used slot_reserved_mask, > > and instead needs something new like slot_manual_mask. > > No? > > Actually, xen would use something like slot_auto_mask, and > sun4u would use both slot_auto_mask and slot_manual_mask. > > Is it just that this patch touches hw/pci-host/i440fx.c that you > don't like or is it that you don't like adding slot_reserved_mask_manual > and pci_bus_ignore_slot_reserved_mask_manual, or is it both > that you don't like? I don't like the enforce_slot_reserved_mask_manual flag - I prefer straight forward logic with no branches in the common code. > If it's the former that you don't like, the call to > pci_bus_ignore_slot_reserved_mask_manual can be moved to > xen_igd_reserve_slot in hw/xen/xen_pt.c and this would > avoid touching hw/pci-host/i440fx.c. > > If it's the latter that you don't like, both slot_reserved_mask_manual > and pci_bus_ignore_slot_reserved_mask_manual can be removed > and this can be implemented with two independent slot masks: > > rename slot_reserved_mask as slot_auto_mask - used by both xen and sun4u > slot_manual_mask - new mask, used only by sun4u. Sounds good to me, except let's add "reserved" in here. slot_reserved_mask_auto, slot_reserved_mask_manual ? > We would also need to have two sets of accessor functions in this case, one > set to access slot_auto_mask, and the other to access slot_manual_mask. > Since the sun4u machine does not need to either get the value of > slot_manual_mask or clear the slot_manual_mask, slot_manual_mask > would only need to have one accessor function to set the value of the > mask. slot_auto_mask would have all three accessor functions that xen > needs to use. > > Would that be OK? Sounds good to me. > > > > > --- > > > Changelog > > > > > > v2: Change Subject of patch from > > > "pci: add enforce_slot_reserved_mask_manual property" To > > > "pci: allow slot_reserved_mask to be ignored with manual slot assignment" > > > > > > Add pci_bus_ignore_slot_reserved_mask_manual function > > > > > > Call pci_bus_ignore_slot_reserved_mask_manual at appropriate place > > > in hw/pci-host/i440fx.c > > > > > > hw/pci-host/i440fx.c | 1 + > > > hw/pci/pci.c | 14 +++++++++++++- > > > include/hw/pci/pci.h | 1 + > > > include/hw/pci/pci_bus.h | 1 + > > > 4 files changed, 16 insertions(+), 1 deletion(-) > > > > > > diff --git a/hw/pci-host/i440fx.c b/hw/pci-host/i440fx.c > > > index 262f82c303..8e00b88926 100644 > > > --- a/hw/pci-host/i440fx.c > > > +++ b/hw/pci-host/i440fx.c > > > @@ -257,6 +257,7 @@ PCIBus *i440fx_init(const char *pci_type, > > > s = PCI_HOST_BRIDGE(dev); > > > b = pci_root_bus_new(dev, NULL, pci_address_space, > > > address_space_io, 0, TYPE_PCI_BUS); > > > + pci_bus_ignore_slot_reserved_mask_manual(b); > > > s->bus = b; > > > object_property_add_child(qdev_get_machine(), "i440fx", OBJECT(dev)); > > > sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal); > > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > > > index 8a87ccc8b0..670ecc6986 100644 > > > --- a/hw/pci/pci.c > > > +++ b/hw/pci/pci.c > > > @@ -501,6 +501,7 @@ static void pci_root_bus_internal_init(PCIBus *bus, DeviceState *parent, > > > assert(PCI_FUNC(devfn_min) == 0); > > > bus->devfn_min = devfn_min; > > > bus->slot_reserved_mask = 0x0; > > > + bus->enforce_slot_reserved_mask_manual = true; > > > bus->address_space_mem = address_space_mem; > > > bus->address_space_io = address_space_io; > > > bus->flags |= PCI_BUS_IS_ROOT; > > > @@ -1116,6 +1117,17 @@ static bool pci_bus_devfn_reserved(PCIBus *bus, int devfn) > > > return bus->slot_reserved_mask & (1UL << PCI_SLOT(devfn)); > > > } > > > > > > +static bool pci_bus_devfn_reserved_manual(PCIBus *bus, int devfn) > > > +{ > > > + return bus->enforce_slot_reserved_mask_manual && > > > + (bus->slot_reserved_mask & (1UL << PCI_SLOT(devfn))); > > > +} > > > + > > > +void pci_bus_ignore_slot_reserved_mask_manual(PCIBus *bus) > > > +{ > > > + bus->enforce_slot_reserved_mask_manual = false; > > > +} > > > + > > > uint32_t pci_bus_get_slot_reserved_mask(PCIBus *bus) > > > { > > > return bus->slot_reserved_mask; > > > @@ -1164,7 +1176,7 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, > > > "or reserved", name); > > > return NULL; > > > found: ; > > > - } else if (pci_bus_devfn_reserved(bus, devfn)) { > > > + } else if (pci_bus_devfn_reserved_manual(bus, devfn)) { > > > error_setg(errp, "PCI: slot %d function %d not available for %s," > > > " reserved", > > > PCI_SLOT(devfn), PCI_FUNC(devfn), name); > > > diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h > > > index 935b4b91b4..48d29ec234 100644 > > > --- a/include/hw/pci/pci.h > > > +++ b/include/hw/pci/pci.h > > > @@ -287,6 +287,7 @@ void pci_bus_irqs(PCIBus *bus, pci_set_irq_fn set_irq, > > > void pci_bus_map_irqs(PCIBus *bus, pci_map_irq_fn map_irq); > > > void pci_bus_irqs_cleanup(PCIBus *bus); > > > int pci_bus_get_irq_level(PCIBus *bus, int irq_num); > > > +void pci_bus_ignore_slot_reserved_mask_manual(PCIBus *bus); > > > uint32_t pci_bus_get_slot_reserved_mask(PCIBus *bus); > > > void pci_bus_set_slot_reserved_mask(PCIBus *bus, uint32_t mask); > > > void pci_bus_clear_slot_reserved_mask(PCIBus *bus, uint32_t mask); > > > diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h > > > index 5653175957..e0f15ee9be 100644 > > > --- a/include/hw/pci/pci_bus.h > > > +++ b/include/hw/pci/pci_bus.h > > > @@ -37,6 +37,7 @@ struct PCIBus { > > > void *iommu_opaque; > > > uint8_t devfn_min; > > > uint32_t slot_reserved_mask; > > > + bool enforce_slot_reserved_mask_manual; > > > pci_set_irq_fn set_irq; > > > pci_map_irq_fn map_irq; > > > pci_route_irq_fn route_intx_to_irq; > > > -- > > > 2.39.2 > >