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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 9F248C282C8 for ; Mon, 28 Jan 2019 11:48:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 741322086C for ; Mon, 28 Jan 2019 11:48:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726669AbfA1Lsy (ORCPT ); Mon, 28 Jan 2019 06:48:54 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:44030 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726611AbfA1Lsx (ORCPT ); Mon, 28 Jan 2019 06:48:53 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5FB72EBD; Mon, 28 Jan 2019 03:48:53 -0800 (PST) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3B85C3F59C; Mon, 28 Jan 2019 03:48:51 -0800 (PST) Subject: Re: [PATCH v9 01/26] arm64: Fix HCR.TGE status for NMI contexts To: Julien Thierry , linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, daniel.thompson@linaro.org, joel@joelfernandes.org, marc.zyngier@arm.com, christoffer.dall@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, mark.rutland@arm.com, Arnd Bergmann , linux-arch@vger.kernel.org, stable@vger.kernel.org References: <1548084825-8803-1-git-send-email-julien.thierry@arm.com> <1548084825-8803-2-git-send-email-julien.thierry@arm.com> From: James Morse Message-ID: <8e8c4f5b-5b83-7bbc-1b84-36d68e210968@arm.com> Date: Mon, 28 Jan 2019 11:48:49 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <1548084825-8803-2-git-send-email-julien.thierry@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Hi Julien, On 21/01/2019 15:33, Julien Thierry wrote: > When using VHE, the host needs to clear HCR_EL2.TGE bit in order > to interract with guest TLBs, switching from EL2&0 translation regime (interact) > to EL1&0. > > However, some non-maskable asynchronous event could happen while TGE is > cleared like SDEI. Because of this address translation operations > relying on EL2&0 translation regime could fail (tlb invalidation, > userspace access, ...). > > Fix this by properly setting HCR_EL2.TGE when entering NMI context and > clear it if necessary when returning to the interrupted context. Yes please. This would not have been fun to debug! Reviewed-by: James Morse I was looking for why we need core code to do this, instead of updating the arch's call sites. Your 'irqdesc: Add domain handlers for NMIs' patch (pointed to from the cover letter) is the reason: core-code calls nmi_enter()/nmi_exit() itself. Thanks, James > diff --git a/arch/arm64/include/asm/hardirq.h b/arch/arm64/include/asm/hardirq.h > index 1473fc2..94b7481 100644 > --- a/arch/arm64/include/asm/hardirq.h > +++ b/arch/arm64/include/asm/hardirq.h > @@ -19,6 +19,7 @@ > #include > #include > #include > +#include percpu.h? sysreg.h? barrier.h? > @@ -37,6 +38,33 @@ > > #define __ARCH_IRQ_EXIT_IRQS_DISABLED 1 > > +struct nmi_ctx { > + u64 hcr; > +}; > + > +DECLARE_PER_CPU(struct nmi_ctx, nmi_contexts); > + > +#define arch_nmi_enter() \ > + do { \ > + if (is_kernel_in_hyp_mode()) { \ > + struct nmi_ctx *nmi_ctx = this_cpu_ptr(&nmi_contexts); \ > + nmi_ctx->hcr = read_sysreg(hcr_el2); \ > + if (!(nmi_ctx->hcr & HCR_TGE)) { \ > + write_sysreg(nmi_ctx->hcr | HCR_TGE, hcr_el2); \ > + isb(); \ > + } \ > + } \ > + } while (0) > + > +#define arch_nmi_exit() \ > + do { \ > + if (is_kernel_in_hyp_mode()) { \ > + struct nmi_ctx *nmi_ctx = this_cpu_ptr(&nmi_contexts); \ > + if (!(nmi_ctx->hcr & HCR_TGE)) \ > + write_sysreg(nmi_ctx->hcr, hcr_el2); \ > + } \ > + } while (0) > + > static inline void ack_bad_irq(unsigned int irq) > { > extern unsigned long irq_err_count; > diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h > index 0fbbcdf..da0af63 100644 > --- a/include/linux/hardirq.h > +++ b/include/linux/hardirq.h > @@ -60,8 +60,14 @@ static inline void rcu_nmi_exit(void) > */ > extern void irq_exit(void); > > +#ifndef arch_nmi_enter > +#define arch_nmi_enter() do { } while (0) > +#define arch_nmi_exit() do { } while (0) > +#endif > + > #define nmi_enter() \ > do { \ > + arch_nmi_enter(); \ > printk_nmi_enter(); \ > lockdep_off(); \ > ftrace_nmi_enter(); \ > @@ -80,6 +86,7 @@ static inline void rcu_nmi_exit(void) > ftrace_nmi_exit(); \ > lockdep_on(); \ > printk_nmi_exit(); \ > + arch_nmi_exit(); \ > } while (0) > > #endif /* LINUX_HARDIRQ_H */ >