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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 65452CA5FB3 for ; Thu, 1 Oct 2026 08:47:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=q9AphvVzQ6TwHNtQrEC6gsLJYjt0J8t1eyMGTtUQ2CE=; b=iT//Ks9artdZr9s7jp9XpsjhgZ oj4oW9zyz6ncCEqvpJUduIV+sGBmE2DR4gBirmDpC930IrW444pv3RiEFjs5Dm2IOm9pyiKzybbs9 tQaaUoF5YmPU2o2RyW1rEVgcps4EpviB+++zxTqKOr8Fom0P/wK4i8FHsvnraGaQv+28dqE7a1Km5 McTBP4PVbLd580My5PAKOPddqHx2go+0lKpXXckInRSyoHFZVtGpAvcr7PjiKiFDfBk3fz92T9kIb POgo0UuBLsf/8FuBTB2fdT/DeMwLpblpD4dafIT8zb/pLckpVpfqDejbz9vmRfrFTLK24wNw+rgqh PXC1Uf1w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCCRK-00000008Fe7-0tA4; Thu, 01 Oct 2026 08:46:54 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCCRG-00000008FaE-1AiD for linux-arm-kernel@lists.infradead.org; Thu, 01 Oct 2026 08:46:52 +0000 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 5E7E4143D; Thu, 1 Oct 2026 01:46:46 -0700 (PDT) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.2.197.99]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 542C83F85F; Thu, 1 Oct 2026 01:46:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790844409; bh=2wRHvrkIbSPvvWwzfecNB7c/ZEPCG3huYLztmO2+diA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ub5sOlQEJnO0O7t4RnjDvWTPHzWqxO48fqJInAiOEbflV171Jh+yA6KGQ8vX+mYtQ Zb7BzEE2JVn9bZrJIB3DllgEewVHDsU+gOf5b2HFnjE5aq31PoAvEZAvuowmoL83Jn R4xiw2kRQQJCOEFj8MGCzifsnksI+galZiaGrRpI= From: Suzuki K Poulose To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: maz@kernel.org, will@kernel.org, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, steven.price@arm.com, aneesh.kumar@kernel.org, oupton@kernel.org, gshan@redhat.com, joey.gouly@arm.com, tabba@google.com, yuzenghui@huawei.com, linux-coco@lists.linux.dev, gankulkarni@os.amperecomputing.com, sdonthineni@nvidia.com, alpergun@google.com, fj0570is@fujitsu.com, WeiLin.Chang@arm.com, lpieralisi@kernel.org, enju.kohei@fujitsu.com, sudeep.holla@arm.com, jonathan.cameron@oss.qualcomm.com, Suzuki K Poulose , "Rafael J. Wysocki" , Len Brown , Pavel Machek , linux-pm@vger.kernel.org Subject: [PATCH v21 7/9] arm64: Block hibernate and kexec while RMM is active Date: Thu, 1 Oct 2026 09:45:53 +0100 Message-ID: <20261001084555.1456543-8-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261001084555.1456543-1-suzuki.poulose@arm.com> References: <20261001084555.1456543-1-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261001_014650_390920_DFAE1589 X-CRM114-Status: GOOD ( 21.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org RMM can be deactivated only after all delegated granules have been reclaimed. If a new kernel is entered while any granules remain in the Realm PAS, accesses to that memory can raise a Granule Protection Fault and be fatal to the new kernel. Crash kexec/kdump needs separate handling. It can be supported only once the crash kernel can tolerate delegated memory inherited from the primary kernel. i.e., be able to read the pages safely and fixup the GPF. Until then disable the kexec completely. Hibernate has a similar problem. The image cannot be safely saved for delegated pages, as the RMM doesn't support exporting the pages. Disable both kexec and hiberation while the RMM is active. Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Pavel Machek Cc: linux-pm@vger.kernel.org Signed-off-by: Suzuki K Poulose --- Changes since v20: - Add arch_hibernation_available() hook for archs to have a say and drop the other checks. Changes since v19: - New patch to disable kexec and hibernation with RMM --- arch/arm64/kernel/hibernate.c | 14 ++++++++++++++ arch/arm64/kernel/machine_kexec.c | 11 +++++++++++ include/linux/suspend.h | 1 + kernel/power/hibernate.c | 8 +++++++- 4 files changed, 33 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c index 7bf1174277772..08e03d24b93a8 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -10,6 +10,8 @@ * Copyright (C) 2006 Rafael J. Wysocki */ #define pr_fmt(x) "hibernate: " x + +#include #include #include #include @@ -105,6 +107,18 @@ void notrace restore_processor_state(void) { } +bool arch_hibernation_available(void) +{ + /* + * If we have activated the RMM, there could be pages that are + * delegated to the RMM. Trying to save them to the image will be fatal. + * Also, we donate pages to the RMM at activation and restoring data + * to those pages are going to be fatal. + * Hence, disable the hibernation when the RMM is active + */ + return !cpus_are_stuck_in_kernel() && !is_rmm_active(); +} + int arch_hibernation_header_save(void *addr, unsigned int max_size) { struct arch_hibernate_hdr *hdr = addr; diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index 8f9bc2327dc85..48f343704cb54 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -6,6 +6,7 @@ * Copyright (C) Huawei Futurewei Technologies. */ +#include #include #include #include @@ -59,6 +60,16 @@ int machine_kexec_prepare(struct kimage *kimage) return -EBUSY; } + /* + * We will be able to allow kdump to proceed, once we have the support + * for handling GPF from vmcore accesses to delegated pages. Until then + * block kexec completely. + */ + if (is_rmm_active()) { + pr_err("Can't kexec: RMM is active.\n"); + return -EBUSY; + } + return 0; } diff --git a/include/linux/suspend.h b/include/linux/suspend.h index b02876f1ae38a..a3815027773c5 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -401,6 +401,7 @@ int hibernate_quiet_exec(int (*func)(void *data), void *data); int hibernate_resume_nonboot_cpu_disable(void); int arch_hibernation_header_save(void *addr, unsigned int max_size); int arch_hibernation_header_restore(void *addr); +bool arch_hibernation_available(void); #else /* CONFIG_HIBERNATION */ static inline void register_nosave_region(unsigned long b, unsigned long e) {} diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index d2479c69d71a4..9d9d53828542f 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -106,11 +106,17 @@ bool hibernation_in_progress(void) return !atomic_read(&hibernate_atomic); } +__weak bool arch_hibernation_available(void) +{ + return true; +} + bool hibernation_available(void) { return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION) && - !secretmem_active() && !cxl_mem_active(); + !secretmem_active() && !cxl_mem_active() && + arch_hibernation_available(); } /** -- 2.43.0