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 5773FC433F5 for ; Wed, 29 Sep 2021 12:35:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F325761406 for ; Wed, 29 Sep 2021 12:35:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F325761406 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 7CB0A940022; Wed, 29 Sep 2021 08:35:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 77A7F940020; Wed, 29 Sep 2021 08:35:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 64273940022; Wed, 29 Sep 2021 08:35:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0151.hostedemail.com [216.40.44.151]) by kanga.kvack.org (Postfix) with ESMTP id 565CE940020 for ; Wed, 29 Sep 2021 08:35:22 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 08CA439B1A for ; Wed, 29 Sep 2021 12:35:22 +0000 (UTC) X-FDA: 78640556484.23.CE7FAB4 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf22.hostedemail.com (Postfix) with ESMTP id 91214190D for ; Wed, 29 Sep 2021 12:35:21 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 43D7B613A0; Wed, 29 Sep 2021 12:35:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632918920; bh=Hu/yKy3l7uo79+zSzWlyiDToH/uMoO95d8UxPVr/d/o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=e9vbIvX6E9RClEiNdzxtftrYOJcEyZMx6jMKfHWdFwCQhFgx0kCFN4oGOCagdnzL2 4oYFs1pBNVH8O6LfR38zGFX1bpF9quWSn9pnnkJKw+Ix2ynGt68d99PJwBm1yMP7HC 25Y+kExEggSfnsq3MIv93/TvQCceT0xr8da/W4KjRRQkxGx32ACJB/MH8Mi8qT90Lk aROC9lx9p18/2rN7NmvJHDYlVeCu4dT35vFBDamYv28FnX4cZEuIl+Cl9nkm7m1tes WWVOlRO4C660OGaZyhDOhzpMgMYpIUCX1l2WIzVd2CzqRD92w44Mu3HNfbGO9G81PG h3ArF1z58qEaA== Date: Wed, 29 Sep 2021 13:35:13 +0100 From: Will Deacon To: Pasha Tatashin Cc: jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, corbet@lwn.net, catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, maz@kernel.org, james.morse@arm.com, vladimir.murzin@arm.com, matthias.bgg@gmail.com, linux-mm@kvack.org, mark.rutland@arm.com, steve.capper@arm.com, rfontana@redhat.com, tglx@linutronix.de, selindag@gmail.com, tyhicks@linux.microsoft.com, kernelfans@gmail.com, akpm@linux-foundation.org, madvenka@linux.microsoft.com Subject: Re: [PATCH v17 08/15] arm64: kexec: configure EL2 vectors for kexec Message-ID: <20210929123513.GC21631@willie-the-truck> References: <20210916231325.125533-1-pasha.tatashin@soleen.com> <20210916231325.125533-9-pasha.tatashin@soleen.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210916231325.125533-9-pasha.tatashin@soleen.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 91214190D X-Stat-Signature: ty8qdjbpk538tcgdwqbfj7p4y5ehrb4j Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=e9vbIvX6; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf22.hostedemail.com: domain of will@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=will@kernel.org X-HE-Tag: 1632918921-300089 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Sep 16, 2021 at 07:13:18PM -0400, Pasha Tatashin wrote: > If we have a EL2 mode without VHE, the EL2 vectors are needed in order > to switch to EL2 and jump to new world with hypervisor privileges. > > In preparation to MMU enabled relocation, configure our EL2 table now. > > Kexec uses #HVC_SOFT_RESTART to branch to the new world, so extend > el1_sync vector that is provided by trans_pgd_copy_el2_vectors() to > support this case. > > Signed-off-by: Pasha Tatashin > --- > arch/arm64/Kconfig | 2 +- > arch/arm64/include/asm/kexec.h | 1 + > arch/arm64/kernel/asm-offsets.c | 1 + > arch/arm64/kernel/machine_kexec.c | 31 +++++++++++++++++++++++++++++++ > arch/arm64/mm/trans_pgd-asm.S | 9 ++++++++- > 5 files changed, 42 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 5c7ae4c3954b..552a057b40af 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1135,7 +1135,7 @@ config CRASH_DUMP > > config TRANS_TABLE > def_bool y > - depends on HIBERNATION > + depends on HIBERNATION || KEXEC_CORE > > config XEN_DOM0 > def_bool y > diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h > index 00dbcc71aeb2..753a1c398898 100644 > --- a/arch/arm64/include/asm/kexec.h > +++ b/arch/arm64/include/asm/kexec.h > @@ -96,6 +96,7 @@ struct kimage_arch { > void *dtb; > phys_addr_t dtb_mem; > phys_addr_t kern_reloc; > + phys_addr_t el2_vectors; > }; > > #ifdef CONFIG_KEXEC_FILE > diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c > index 1d3319c7518e..6a2b8b1a4872 100644 > --- a/arch/arm64/kernel/asm-offsets.c > +++ b/arch/arm64/kernel/asm-offsets.c > @@ -174,6 +174,7 @@ int main(void) > #endif > #ifdef CONFIG_KEXEC_CORE > DEFINE(KIMAGE_ARCH_DTB_MEM, offsetof(struct kimage, arch.dtb_mem)); > + DEFINE(KIMAGE_ARCH_EL2_VECTORS, offsetof(struct kimage, arch.el2_vectors)); > DEFINE(KIMAGE_HEAD, offsetof(struct kimage, head)); > DEFINE(KIMAGE_START, offsetof(struct kimage, start)); > BLANK(); > diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c > index e210b19592c6..59a4b4172b68 100644 > --- a/arch/arm64/kernel/machine_kexec.c > +++ b/arch/arm64/kernel/machine_kexec.c > @@ -21,6 +21,7 @@ > #include > #include > #include > +#include > > #include "cpu-reset.h" > > @@ -43,7 +44,9 @@ static void _kexec_image_info(const char *func, int line, > pr_debug(" start: %lx\n", kimage->start); > pr_debug(" head: %lx\n", kimage->head); > pr_debug(" nr_segments: %lu\n", kimage->nr_segments); > + pr_debug(" dtb_mem: %pa\n", &kimage->arch.dtb_mem); > pr_debug(" kern_reloc: %pa\n", &kimage->arch.kern_reloc); > + pr_debug(" el2_vectors: %pa\n", &kimage->arch.el2_vectors); > > for (i = 0; i < kimage->nr_segments; i++) { > pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n", > @@ -143,9 +146,27 @@ static void kexec_segment_flush(const struct kimage *kimage) > } > } > > +/* Allocates pages for kexec page table */ > +static void *kexec_page_alloc(void *arg) > +{ > + struct kimage *kimage = (struct kimage *)arg; > + struct page *page = kimage_alloc_control_pages(kimage, 0); > + > + if (!page) > + return NULL; > + > + memset(page_address(page), 0, PAGE_SIZE); Hmm, I think we might be missing barriers here to ensure that the zeroes are visible to the page-table walker before we plumb the page into the page-table. Usually, that's taken care of by the smp_wmb() in __pXX_alloc() but I can't see that here. Is it hiding? Will