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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 2CCFDC433E0 for ; Mon, 22 Feb 2021 15:02:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2C4964EEF for ; Mon, 22 Feb 2021 15:02:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230141AbhBVPCM (ORCPT ); Mon, 22 Feb 2021 10:02:12 -0500 Received: from foss.arm.com ([217.140.110.172]:51614 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230113AbhBVPCL (ORCPT ); Mon, 22 Feb 2021 10:02:11 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E7C5A31B; Mon, 22 Feb 2021 07:01:21 -0800 (PST) Received: from [192.168.0.110] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E73633F73B; Mon, 22 Feb 2021 07:01:20 -0800 (PST) Subject: Re: [PATCH kvmtool 01/21] ioport: Remove ioport__setup_arch() To: Andre Przywara Cc: Will Deacon , Julien Thierry , kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, Marc Zyngier References: <20201210142908.169597-1-andre.przywara@arm.com> <20201210142908.169597-2-andre.przywara@arm.com> <814e0cd9-5e54-fade-f05c-80ea2b4a9039@arm.com> <20210211171648.36000cce@slackpad.fritz.box> <111b6cd6-ddf3-ec67-b782-67120be97943@arm.com> <20210217155459.3a4bc991@slackpad.fritz.box> <20210222102333.2f1cb9e2@slackpad.fritz.box> From: Alexandru Elisei Message-ID: <861fd8a5-240e-3439-877b-28ba3490ebb4@arm.com> Date: Mon, 22 Feb 2021 15:01:28 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210222102333.2f1cb9e2@slackpad.fritz.box> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi Andre, On 2/22/21 10:23 AM, Andre Przywara wrote: > On Wed, 17 Feb 2021 16:46:47 +0000 > Andre Przywara wrote: > >> On Thu, 11 Feb 2021 17:32:01 +0000 >> Alexandru Elisei wrote: >> >> Hi, >> >>> On 2/11/21 5:16 PM, Andre Przywara wrote: >>>> On Wed, 10 Feb 2021 17:44:59 +0000 >>>> Alexandru Elisei wrote: >>>> >>>> Hi Alex, >>>> >>>>> On 12/10/20 2:28 PM, Andre Przywara wrote: >>>>>> Since x86 had a special need for registering tons of special I/O ports, >>>>>> we had an ioport__setup_arch() callback, to allow each architecture >>>>>> to do the same. As it turns out no one uses it beside x86, so we remove >>>>>> that unnecessary abstraction. >>>>>> >>>>>> The generic function was registered via a device_base_init() call, so >>>>>> we just do the same for the x86 specific function only, and can remove >>>>>> the unneeded ioport__setup_arch(). >>>>>> >>>>>> Signed-off-by: Andre Przywara >>>>>> --- >>>>>> arm/ioport.c | 5 ----- >>>>>> include/kvm/ioport.h | 1 - >>>>>> ioport.c | 28 ---------------------------- >>>>>> mips/kvm.c | 5 ----- >>>>>> powerpc/ioport.c | 6 ------ >>>>>> x86/ioport.c | 25 ++++++++++++++++++++++++- >>>>>> 6 files changed, 24 insertions(+), 46 deletions(-) >>>>>> >>>>>> diff --git a/arm/ioport.c b/arm/ioport.c >>>>>> index 2f0feb9a..24092c9d 100644 >>>>>> --- a/arm/ioport.c >>>>>> +++ b/arm/ioport.c >>>>>> @@ -1,11 +1,6 @@ >>>>>> #include "kvm/ioport.h" >>>>>> #include "kvm/irq.h" >>>>>> >>>>>> -int ioport__setup_arch(struct kvm *kvm) >>>>>> -{ >>>>>> - return 0; >>>>>> -} >>>>>> - >>>>>> void ioport__map_irq(u8 *irq) >>>>>> { >>>>>> *irq = irq__alloc_line(); >>>>>> diff --git a/include/kvm/ioport.h b/include/kvm/ioport.h >>>>>> index 039633f7..d0213541 100644 >>>>>> --- a/include/kvm/ioport.h >>>>>> +++ b/include/kvm/ioport.h >>>>>> @@ -35,7 +35,6 @@ struct ioport_operations { >>>>>> enum irq_type)); >>>>>> }; >>>>>> >>>>>> -int ioport__setup_arch(struct kvm *kvm); >>>>>> void ioport__map_irq(u8 *irq); >>>>>> >>>>>> int __must_check ioport__register(struct kvm *kvm, u16 port, struct ioport_operations *ops, >>>>>> diff --git a/ioport.c b/ioport.c >>>>>> index 844a832d..667e8386 100644 >>>>>> --- a/ioport.c >>>>>> +++ b/ioport.c >>>>>> @@ -158,21 +158,6 @@ int ioport__unregister(struct kvm *kvm, u16 port) >>>>>> return 0; >>>>>> } >>>>>> >>>>>> -static void ioport__unregister_all(void) >>>>>> -{ >>>>>> - struct ioport *entry; >>>>>> - struct rb_node *rb; >>>>>> - struct rb_int_node *rb_node; >>>>>> - >>>>>> - rb = rb_first(&ioport_tree); >>>>>> - while (rb) { >>>>>> - rb_node = rb_int(rb); >>>>>> - entry = ioport_node(rb_node); >>>>>> - ioport_unregister(&ioport_tree, entry); >>>>>> - rb = rb_first(&ioport_tree); >>>>>> - } >>>>>> -} >>>>> I get the impression this is a rebasing artifact. The commit message doesn't >>>>> mention anything about removing ioport__exit() -> ioport__unregister_all(), and as >>>>> far as I can tell it's still needed because there are places other than >>>>> ioport__setup_arch() from where ioport__register() is called. >>>> I agree that the commit message is a bit thin on this fact, but the >>>> functionality of ioport__unregister_all() is now in >>>> x86/ioport.c:ioport__remove_arch(). I think removing ioport__init() >>>> without removing ioport__exit() as well would look very weird, if not >>>> hackish. >>> Not necessarily. ioport__unregister_all() removes the ioports added by >>> x86/ioport.c::ioport__setup_arch(), *plus* ioports added by different devices, >>> like serial, rtc, virtio-pci and vfio-pci (which are used by arm/arm64). >> Right, indeed. Not that it really matters, since we are about to exit >> anyway, but it looks indeed I need to move this to a generic teardown >> method, or actually just keep that part here in this file. >> >> Will give this a try. > Well, now having a closer look I needed to remove this from here, > because this whole file will go away. > To keep the current functionality, we would need to add it to mmio.c, > and interestingly we don't do any kind of similar cleanup there for the > MMIO regions (probably this is kvmtool exiting anyway, see above). This is a very good point. If the MMIO emulation doesn't unregister each MMIO region before exiting (and has never done that since it was implemented), then I don't think there's a reason that we should add it now. After all, kvmtool will terminate after calling dev_base_exit destructors, which will take care of deallocating the entire process memory. Thanks, Alex > > I will see if I can introduce it there, for good measure. > > Cheers, > Andre > > >> Thanks! >> Andre >> >>>> I can amend the commit message to mention this, or is there anything >>>> else I missed? >>>> >>>> Cheers, >>>> Andre >>>> >>>>>> - >>>>>> static const char *to_direction(int direction) >>>>>> { >>>>>> if (direction == KVM_EXIT_IO_IN) >>>>>> @@ -220,16 +205,3 @@ out: >>>>>> >>>>>> return !kvm->cfg.ioport_debug; >>>>>> } >>>>>> - >>>>>> -int ioport__init(struct kvm *kvm) >>>>>> -{ >>>>>> - return ioport__setup_arch(kvm); >>>>>> -} >>>>>> -dev_base_init(ioport__init); >>>>>> - >>>>>> -int ioport__exit(struct kvm *kvm) >>>>>> -{ >>>>>> - ioport__unregister_all(); >>>>>> - return 0; >>>>>> -} >>>>>> -dev_base_exit(ioport__exit); >>>>>> diff --git a/mips/kvm.c b/mips/kvm.c >>>>>> index 26355930..e110e5d5 100644 >>>>>> --- a/mips/kvm.c >>>>>> +++ b/mips/kvm.c >>>>>> @@ -100,11 +100,6 @@ void kvm__irq_trigger(struct kvm *kvm, int irq) >>>>>> die_perror("KVM_IRQ_LINE ioctl"); >>>>>> } >>>>>> >>>>>> -int ioport__setup_arch(struct kvm *kvm) >>>>>> -{ >>>>>> - return 0; >>>>>> -} >>>>>> - >>>>>> bool kvm__arch_cpu_supports_vm(void) >>>>>> { >>>>>> return true; >>>>>> diff --git a/powerpc/ioport.c b/powerpc/ioport.c >>>>>> index 0c188b61..a5cff4ee 100644 >>>>>> --- a/powerpc/ioport.c >>>>>> +++ b/powerpc/ioport.c >>>>>> @@ -12,12 +12,6 @@ >>>>>> >>>>>> #include >>>>>> >>>>>> -int ioport__setup_arch(struct kvm *kvm) >>>>>> -{ >>>>>> - /* PPC has no legacy ioports to set up */ >>>>>> - return 0; >>>>>> -} >>>>>> - >>>>>> void ioport__map_irq(u8 *irq) >>>>>> { >>>>>> } >>>>>> diff --git a/x86/ioport.c b/x86/ioport.c >>>>>> index 7ad7b8f3..8c5c7699 100644 >>>>>> --- a/x86/ioport.c >>>>>> +++ b/x86/ioport.c >>>>>> @@ -69,7 +69,7 @@ void ioport__map_irq(u8 *irq) >>>>>> { >>>>>> } >>>>>> >>>>>> -int ioport__setup_arch(struct kvm *kvm) >>>>>> +static int ioport__setup_arch(struct kvm *kvm) >>>>>> { >>>>>> int r; >>>>>> >>>>>> @@ -150,3 +150,26 @@ int ioport__setup_arch(struct kvm *kvm) >>>>>> >>>>>> return 0; >>>>>> } >>>>>> +dev_base_init(ioport__setup_arch); >>>>>> + >>>>>> +static int ioport__remove_arch(struct kvm *kvm) >>>>>> +{ >>>>>> + ioport__unregister(kvm, 0x510); >>>>>> + ioport__unregister(kvm, 0x402); >>>>>> + ioport__unregister(kvm, 0x03D5); >>>>>> + ioport__unregister(kvm, 0x03D4); >>>>>> + ioport__unregister(kvm, 0x0378); >>>>>> + ioport__unregister(kvm, 0x0278); >>>>>> + ioport__unregister(kvm, 0x00F0); >>>>>> + ioport__unregister(kvm, 0x00ED); >>>>>> + ioport__unregister(kvm, IOPORT_DBG); >>>>>> + ioport__unregister(kvm, 0x00C0); >>>>>> + ioport__unregister(kvm, 0x00A0); >>>>>> + ioport__unregister(kvm, 0x0092); >>>>>> + ioport__unregister(kvm, 0x0040); >>>>>> + ioport__unregister(kvm, 0x0020); >>>>>> + ioport__unregister(kvm, 0x0000); >>>>>> + >>>>>> + return 0; >>>>>> +} >>>>>> +dev_base_exit(ioport__remove_arch);