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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 D898BC433DB for ; Sun, 3 Jan 2021 18:34:58 +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 36A7F207FB for ; Sun, 3 Jan 2021 18:34:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36A7F207FB Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=nongnu.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45962 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kw8DQ-0006bM-OM for qemu-devel@archiver.kernel.org; Sun, 03 Jan 2021 13:34:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:44418) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kw89v-0004OY-Ni; Sun, 03 Jan 2021 13:31:21 -0500 Received: from zero.eik.bme.hu ([2001:738:2001:2001::2001]:59933) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kw89r-00006I-8u; Sun, 03 Jan 2021 13:31:18 -0500 Received: from zero.eik.bme.hu (blah.eik.bme.hu [152.66.115.182]) by localhost (Postfix) with SMTP id B01E4747601; Sun, 3 Jan 2021 19:31:09 +0100 (CET) Received: by zero.eik.bme.hu (Postfix, from userid 432) id 546487470DD; Sun, 3 Jan 2021 19:31:09 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by zero.eik.bme.hu (Postfix) with ESMTP id 51D9F74645F; Sun, 3 Jan 2021 19:31:09 +0100 (CET) Date: Sun, 3 Jan 2021 19:31:09 +0100 (CET) To: Mark Cave-Ayland Subject: Re: [RFC PATCH 2/5] via-ide: Fix fuloong2e support In-Reply-To: <3b45dfea-0534-b61f-8fef-a38b1b1a4236@ilande.co.uk> Message-ID: References: <20210101231215.1870611-1-f4bug@amsat.org> <20210101231215.1870611-3-f4bug@amsat.org> <3b45dfea-0534-b61f-8fef-a38b1b1a4236@ilande.co.uk> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="3866299591-553687379-1609698669=:62321" Received-SPF: pass client-ip=2001:738:2001:2001::2001; envelope-from=balaton@eik.bme.hu; helo=zero.eik.bme.hu X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Aleksandar Rikalo , qemu-block@nongnu.org, Guenter Roeck , Huacai Chen , =?ISO-8859-15?Q?Philippe_Mathieu-Daud=E9?= , Wainer dos Santos Moschetta , qemu-devel@nongnu.org, Artyom Tarasenko , Cleber Rosa , John Snow , Aurelien Jarno Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Reply-to: BALATON Zoltan From: BALATON Zoltan via This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --3866299591-553687379-1609698669=:62321 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8BIT On Sun, 3 Jan 2021, Mark Cave-Ayland wrote: > On 01/01/2021 23:12, Philippe Mathieu-Daudé wrote: >> From: Guenter Roeck >> >> The IDE legacy mode emulation has been removed in commit 4ea98d317eb >> ("ide/via: Implement and use native PCI IDE mode") but some Linux >> kernels (probably including def_config) require legacy mode on the >> Fuloong2e so only emulating native mode did not turn out feasible. >> Add property to via-ide model to make the mode configurable, and set >> legacy mode for Fuloong2e. >> >> [balaton: Use bit in flags for property, add comment for missing BAR4] >> >> Signed-off-by: Guenter Roeck >> Signed-off-by: BALATON Zoltan >> Tested-by: Guenter Roeck >> Reviewed-by: Philippe Mathieu-Daudé >> Reviewed-by: Jiaxun Yang >> Message-Id: >> <17a50e58e6baa26440c7dac83f07fdbba1595439.1609191252.git.balaton@eik.bme.hu> >> Signed-off-by: Philippe Mathieu-Daudé >> --- >> hw/ide/via.c | 19 +++++++++++++++++-- >> hw/mips/fuloong2e.c | 4 +++- >> 2 files changed, 20 insertions(+), 3 deletions(-) >> >> diff --git a/hw/ide/via.c b/hw/ide/via.c >> index be09912b334..2d935b910f8 100644 >> --- a/hw/ide/via.c >> +++ b/hw/ide/via.c >> @@ -26,6 +26,7 @@ >> #include "qemu/osdep.h" >> #include "hw/pci/pci.h" >> +#include "hw/qdev-properties.h" >> #include "migration/vmstate.h" >> #include "qemu/module.h" >> #include "sysemu/dma.h" >> @@ -185,12 +186,19 @@ static void via_ide_realize(PCIDevice *dev, Error >> **errp) >> &d->bus[1], "via-ide1-cmd", 4); >> pci_register_bar(dev, 3, PCI_BASE_ADDRESS_SPACE_IO, &d->cmd_bar[1]); >> - bmdma_setup_bar(d); >> - pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar); >> + if (!(d->flags & BIT(PCI_IDE_LEGACY_MODE))) { >> + /* Missing BAR4 will make Linux driver fall back to legacy PIO >> mode */ >> + bmdma_setup_bar(d); >> + pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, >> &d->bmdma_bar); >> + } >> qdev_init_gpio_in(ds, via_ide_set_irq, 2); >> for (i = 0; i < 2; i++) { >> ide_bus_new(&d->bus[i], sizeof(d->bus[i]), ds, i, 2); >> + if (d->flags & BIT(PCI_IDE_LEGACY_MODE)) { >> + ide_init_ioport(&d->bus[i], NULL, i ? 0x170 : 0x1f0, >> + i ? 0x376 : 0x3f6); >> + } >> ide_init2(&d->bus[i], qdev_get_gpio_in(ds, i)); > > The if() here needs to be removed because the VIA IDE device starts up in > legacy mode. If you look at the PCI bus master specification [1] the table at > the top of page 3 is the breakdown of the PCI_CLASS_PROG byte: the configured > value of 0x8a clearly indicates both channels are in legacy mode, which means > that the PCI BARs are disabled and the controller is fixed to use the legacy > IDE ioports with the option to switch up to native mode. This if says that these ports are enabled when the legacy-mode flag is set, i.e. we only emulate legacy-mode. It is disabled when we only emulate half-native mode for pegasos2. If we leave it there unconditionally as you suggest then we'll emulate (half-)native mode with the PCI BARs containing these regs as well as having legacy ioports enabled at the same time. I can't see how that's cleaner or more like what real hardware does. > This is the main reason that the fuloong2e kernel panics on startup because > its reads PCI_CLASS_PROG, discovers the controller is in legacy mode and then > tries to access the legacy IDE ioports. Since the ioports are no longer > mapped then the kernel crashes. > > (Fun fact: you can change PCI_CLASS_PROG to 0x8f and watch Linux configure > the VIA IDE controller in native mode: it gets quite far before it decides to > eventually panic) > > The fix here is simple: always enable the legacy IDE ioports. Zoltan > mentioned he was concerned about having multiple IDE ports available, but > this is not an issue for 2 reasons: > > 1) Before any of Zoltan's patches were applied, the VIA IDE driver set > PCI_CLASS_PROG to 0x8a with the legacy IDE ports always enabled, and there > were no issues It did not run with pegasos2 back then, only with fuloong2e Linux and even that wasn't tested very much, that's why my patches were needed in the first place so of course there were no issues as it did not work at all once something tried to use native mode like pegasos2 guests. > 2) PCI bus enumeration always leaves the low end of IO space free so that > there are no clashes with legacy ISA devices which can't be freely relocated > in IO space I don't know if that's a valid assumption to expect to be generally true but I've tested pegasos2 with MorphOS after removing the if around ide_init_ioport() above as you say and only leaving it around BAR4 and it still boots, we end up with this memory map: memory-region: pci1-io 0000000000000000-000000000000ffff (prio 0, i/o): pci1-io 0000000000000000-0000000000000007 (prio 0, i/o): dma-chan 0000000000000008-000000000000000f (prio 0, i/o): dma-cont 0000000000000020-0000000000000021 (prio 0, i/o): pic 0000000000000040-0000000000000043 (prio 0, i/o): pit 0000000000000060-0000000000000060 (prio 0, i/o): i8042-data 0000000000000064-0000000000000064 (prio 0, i/o): i8042-cmd 0000000000000070-0000000000000071 (prio 0, i/o): rtc 0000000000000070-0000000000000070 (prio 0, i/o): rtc-index 0000000000000081-0000000000000083 (prio 0, i/o): dma-page 0000000000000087-0000000000000087 (prio 0, i/o): dma-page 0000000000000089-000000000000008b (prio 0, i/o): dma-page 000000000000008f-000000000000008f (prio 0, i/o): dma-page 00000000000000a0-00000000000000a1 (prio 0, i/o): pic 00000000000000b2-00000000000000b3 (prio 0, i/o): apm-io 00000000000000c0-00000000000000cf (prio 0, i/o): dma-chan 00000000000000d0-00000000000000df (prio 0, i/o): dma-cont * 0000000000000170-0000000000000177 (prio 0, i/o): ide 00000000000001ce-00000000000001d1 (prio 0, i/o): vbe * 00000000000001f0-00000000000001f7 (prio 0, i/o): ide 00000000000002f8-00000000000002ff (prio 0, i/o): serial * 0000000000000376-0000000000000376 (prio 0, i/o): ide 0000000000000378-000000000000037f (prio 0, i/o): parallel 00000000000003b4-00000000000003b5 (prio 0, i/o): vga 00000000000003ba-00000000000003ba (prio 0, i/o): vga 00000000000003c0-00000000000003cf (prio 0, i/o): vga 00000000000003d4-00000000000003d5 (prio 0, i/o): vga 00000000000003da-00000000000003da (prio 0, i/o): vga 00000000000003f1-00000000000003f5 (prio 0, i/o): fdc * 00000000000003f6-00000000000003f6 (prio 0, i/o): ide 00000000000003f7-00000000000003f7 (prio 0, i/o): fdc 00000000000004d0-00000000000004d0 (prio 0, i/o): elcr 00000000000004d1-00000000000004d1 (prio 0, i/o): elcr 0000000000000f00-0000000000000fff (prio 0, i/o): via-pm 0000000000000f00-0000000000000f03 (prio 0, i/o): acpi-evt 0000000000000f04-0000000000000f05 (prio 0, i/o): acpi-cnt 0000000000000f08-0000000000000f0b (prio 0, i/o): acpi-tmr 0000000000001000-00000000000010ff (prio 1, i/o): alias ati.io @ati.mmregs 0000000000000000-00000000000000ff 0000000000002000-0000000000002007 (prio 1, i/o): via-ide0-data 0000000000003004-0000000000003007 (prio 1, i/o): via-ide0-cmd 0000000000005000-0000000000005007 (prio 1, i/o): via-ide1-data 0000000000006004-0000000000006007 (prio 1, i/o): via-ide1-cmd 0000000000008000-000000000000800f (prio 1, i/o): via-bmdma-container 0000000000008000-0000000000008003 (prio 0, i/o): via-bmdma 0000000000008004-0000000000008007 (prio 0, i/o): bmdma 0000000000008008-000000000000800b (prio 0, i/o): via-bmdma 000000000000800c-000000000000800f (prio 0, i/o): bmdma 0000000000009000-000000000000901f (prio 1, i/o): uhci 000000000000a000-000000000000a01f (prio 1, i/o): uhci memory-region: system 0000000000000000-ffffffffffffffff (prio 0, i/o): system 0000000000000000-000000001fffffff (prio 0, ram): pegasos2.ram 0000000080000000-00000000bfffffff (prio 0, i/o): alias pci1-mem0-win @pci1-mem 0000000080000000-00000000bfffffff 00000000c0000000-00000000dfffffff (prio 0, i/o): alias pci0-mem0-win @pci0-mem 00000000c0000000-00000000dfffffff 00000000f1000000-00000000f100ffff (prio 0, i/o): mv64361 00000000f8000000-00000000f8ffffff (prio 0, i/o): alias pci0-io-win @pci0-io 0000000000000000-0000000000ffffff 00000000f9000000-00000000f9ffffff (prio 0, i/o): alias pci0-mem1-win @pci0-mem 0000000000000000-0000000000ffffff 00000000fd000000-00000000fdffffff (prio 0, i/o): alias pci1-mem1-win @pci1-mem 0000000000000000-0000000000ffffff 00000000fe000000-00000000feffffff (prio 0, i/o): alias pci1-io-win @pci1-io 0000000000000000-0000000000ffffff 00000000ff800000-00000000ffffffff (prio 0, i/o): alias pci1-mem3-win @pci1-mem 00000000ff800000-00000000ffffffff 00000000fff00000-00000000fff7ffff (prio 0, rom): pegasos2.rom MorphOS uses the via-ide* BARs mapped at 2000-800f and hopefully does not want to put anything or accidentally write to the legacy ide ports marked with "*" above that I think should not be there (and with the if they are not registered in this case) which I think is more like what real hardware does because data sheet says in native mode it ignores legacy ports which is not what your patch with removed if does. >> bmdma_init(&d->bus[i], &d->bmdma[i], d); >> @@ -210,6 +218,12 @@ static void via_ide_exitfn(PCIDevice *dev) >> } >> } >> +static Property via_ide_properties[] = { >> + DEFINE_PROP_BIT("legacy-mode", PCIIDEState, flags, >> PCI_IDE_LEGACY_MODE, >> + false), >> + DEFINE_PROP_END_OF_LIST(), >> +}; > > The other issue with the patch is that the legacy-mode property doesn't have > anything to do with legacy mode: once the legacy IDE ioports are always > enabled, the only thing this property controls is whether PCI BAR 4 is > enabled. It doesn't select legacy mode since this is already the default, and > neither does it force it by fixing the relevant bits in PCI_CLASS_PROG. So then just rename it to break-native-mode or whatever you want, this is not a problem with the patch itself, it's only broken after you remove the if. > PCI BAR 4 is for configuring BMDMA and Linux checks to see if BAR 4 is > non-zero: if it is, then it tries to use BMDMA which is the feature that > actually crashes the fuloong2e Linux kernel. Hence my suggestion to rename That probably means it's not expecting to use anything but legacy mode on fuloong2e but hard to tell without seeing it run on real machine. > the property to "x-disable-bdma": the x- prefix convention clearly marks this > out as an experimental property whilst also correctly describing what is is > used for, just in case it leaks into external qdev configuration. It's ok to change the property name, I think that can be done during merging without having to test everything again as it can't break it but for any other change please provide an alternative patch with your suggestion, but also test it with both fuloong2e and pegasos2, The MorphOS iso is freely downloadable and should work with -device ati-vga,romfile=VGABIOS-lgpl-latest.bin as described on my qmiga.osdn.net page. You can find a working version of pegasos2 emulation here: https://osdn.net/projects/qmiga/scm/git/qemu/tree/pegasos2/ (which is currently still an older version but I plan to update it as I'm splitting it up in smaller patches that I'll submit here later, but that version should work for testing via-ide as nothing has changed in that part). If a patch is posted here I may test it but I don't intend to change this patch any more because I think what you propose here would not make it any better and I don't know if Guenter wants to update it either. >> static void via_ide_class_init(ObjectClass *klass, void *data) >> { >> DeviceClass *dc = DEVICE_CLASS(klass); >> @@ -223,6 +237,7 @@ static void via_ide_class_init(ObjectClass *klass, void >> *data) >> k->device_id = PCI_DEVICE_ID_VIA_IDE; >> k->revision = 0x06; >> k->class_id = PCI_CLASS_STORAGE_IDE; >> + device_class_set_props(dc, via_ide_properties); >> set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); >> } >> diff --git a/hw/mips/fuloong2e.c b/hw/mips/fuloong2e.c >> index 45c596f4fe5..d334fde389f 100644 >> --- a/hw/mips/fuloong2e.c >> +++ b/hw/mips/fuloong2e.c >> @@ -253,7 +253,9 @@ static void vt82c686b_southbridge_init(PCIBus *pci_bus, >> int slot, qemu_irq intc, >> /* Super I/O */ >> isa_create_simple(isa_bus, TYPE_VT82C686B_SUPERIO); >> - dev = pci_create_simple(pci_bus, PCI_DEVFN(slot, 1), "via-ide"); >> + dev = pci_new(PCI_DEVFN(slot, 1), "via-ide"); >> + qdev_prop_set_bit(&dev->qdev, "legacy-mode", true); >> + pci_realize_and_unref(dev, pci_bus, &error_fatal); >> pci_ide_create_devs(dev); >> pci_create_simple(pci_bus, PCI_DEVFN(slot, 2), >> "vt82c686b-usb-uhci"); > > I hope this helps to summarise all my comments from the previous thread. > Given that it is not possible to set default PCI BAR addresses in QEMU due to > the post-qdev PCI bus reset, the ultimate aim should be to devise a couple of > routines pci_enable_bar() and pci_disable_bar() so that the new property can > be removed and controller mode set directly from configuration space writes > to PCI_CLASS_PROG. And as per my reply in the previous thread, I can't see > this happening in the near future. As I wrote in previous reply I think it would be better to solve the problem of removing or changing ISA devices instead which is more of a problem than PCI BARs here but that's something that can be considered later if we accept this as an interim solution now until a better emulation can be written after the necessary changes are made elsewhere in QEMU. > I would really like to see a version of this patchset merged, particularly > the integration test which will be of clear value moving forward. I am not > against hacks like this where they are necessary, but as part of the review > process they need to be understood with the aim being for QEMU to provide the > guest with the most coherent environment possible. I'm working on cleaning the pegasos2 patches so I can submit it here and get it merged. I've already done the vt8231 part (of which the first version of this via-ide patch I've posted in March was also part of but only had time to do the rest now). This vt8231 model is the 24 patch series I've posted yesterday (actually only 3 of those the rest is cleaning up vt82c686b model so we can add vt8231 relatively cleanly) and first half of that was alreay queued. Then there should be only two more patches needed: one adding Marvell system controller chip and finally the actual board code then we can make the acceptance test that would also test via-ide with half-native mode as used on pegasos2. I appreciate your review as long as it's about finding obviously wrong details or suggesting improvements that can be implemented in at most a few days (that's all what I can put in this now) without needing to change anything unrelated to the actual patch. But saying that it is not acceptable and all of this should be done in some completely different way after rewriting half of device emulation in QEMU just to get rid of an if or a flag is not a review that I consider helpful. It's OK to point out how it could be improved later but make it clear that it should not hold back progress and should not be something that prevents merging an otherwise acceptable patch that does not have obviously wrong code or any worse hacks than what we already have in QEMU now. Regards, BALATON Zoltan --3866299591-553687379-1609698669=:62321--