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=-11.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,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 B5E7EC3F68F for ; Sat, 1 Feb 2020 08:48:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 970DB2070C for ; Sat, 1 Feb 2020 08:48:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726484AbgBAIsT (ORCPT ); Sat, 1 Feb 2020 03:48:19 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:56920 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726133AbgBAIsT (ORCPT ); Sat, 1 Feb 2020 03:48:19 -0500 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1ixoRr-0003ea-93; Sat, 01 Feb 2020 09:48:15 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id E2ADC1C1DF9; Sat, 1 Feb 2020 09:48:14 +0100 (CET) Date: Sat, 01 Feb 2020 08:48:14 -0000 From: "tip-bot2 for Dexuan Cui" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/urgent] x86/hyperv: Suspend/resume the hypercall page for hibernation Cc: Dexuan Cui , Thomas Gleixner , Michael Kelley , x86 , LKML In-Reply-To: <1578350559-130275-1-git-send-email-decui@microsoft.com> References: <1578350559-130275-1-git-send-email-decui@microsoft.com> MIME-Version: 1.0 Message-ID: <158054689467.396.9318913619625622500.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/urgent branch of tip: Commit-ID: 05bd330a7fd8875c423fc07d8ddcad73c10e556e Gitweb: https://git.kernel.org/tip/05bd330a7fd8875c423fc07d8ddcad73c10e556e Author: Dexuan Cui AuthorDate: Mon, 06 Jan 2020 14:42:39 -08:00 Committer: Thomas Gleixner CommitterDate: Sat, 01 Feb 2020 09:41:16 +01:00 x86/hyperv: Suspend/resume the hypercall page for hibernation For hibernation the hypercall page must be disabled before the hibernation image is created so that subsequent hypercall operations fail safely. On resume the hypercall page has to be restored and reenabled to ensure proper operation of the resumed kernel. Implement the necessary suspend/resume callbacks. [ tglx: Decrypted changelog ] Signed-off-by: Dexuan Cui Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/1578350559-130275-1-git-send-email-decui@microsoft.com --- arch/x86/hyperv/hv_init.c | 50 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 50 insertions(+) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index caaf4dc..b0da532 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -21,11 +21,15 @@ #include #include #include +#include #include void *hv_hypercall_pg; EXPORT_SYMBOL_GPL(hv_hypercall_pg); +/* Storage to save the hypercall page temporarily for hibernation */ +static void *hv_hypercall_pg_saved; + u32 *hv_vp_index; EXPORT_SYMBOL_GPL(hv_vp_index); @@ -246,6 +250,48 @@ static int __init hv_pci_init(void) return 1; } +static int hv_suspend(void) +{ + union hv_x64_msr_hypercall_contents hypercall_msr; + + /* + * Reset the hypercall page as it is going to be invalidated + * accross hibernation. Setting hv_hypercall_pg to NULL ensures + * that any subsequent hypercall operation fails safely instead of + * crashing due to an access of an invalid page. The hypercall page + * pointer is restored on resume. + */ + hv_hypercall_pg_saved = hv_hypercall_pg; + hv_hypercall_pg = NULL; + + /* Disable the hypercall page in the hypervisor */ + rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); + hypercall_msr.enable = 0; + wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); + + return 0; +} + +static void hv_resume(void) +{ + union hv_x64_msr_hypercall_contents hypercall_msr; + + /* Re-enable the hypercall page */ + rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); + hypercall_msr.enable = 1; + hypercall_msr.guest_physical_address = + vmalloc_to_pfn(hv_hypercall_pg_saved); + wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); + + hv_hypercall_pg = hv_hypercall_pg_saved; + hv_hypercall_pg_saved = NULL; +} + +static struct syscore_ops hv_syscore_ops = { + .suspend = hv_suspend, + .resume = hv_resume, +}; + /* * This function is to be invoked early in the boot sequence after the * hypervisor has been detected. @@ -330,6 +376,8 @@ void __init hyperv_init(void) x86_init.pci.arch_init = hv_pci_init; + register_syscore_ops(&hv_syscore_ops); + return; remove_cpuhp_state: @@ -349,6 +397,8 @@ void hyperv_cleanup(void) { union hv_x64_msr_hypercall_contents hypercall_msr; + unregister_syscore_ops(&hv_syscore_ops); + /* Reset our OS id */ wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);