From patchwork Mon Mar 15 14:22:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 401116 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 0A2C4C2BB1F for ; Mon, 15 Mar 2021 14:25:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D02D36509B for ; Mon, 15 Mar 2021 14:25:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232362AbhCOOYZ (ORCPT ); Mon, 15 Mar 2021 10:24:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:45460 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238121AbhCOOWp (ORCPT ); Mon, 15 Mar 2021 10:22:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0056864F2C; Mon, 15 Mar 2021 14:22:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615818165; bh=KUA8aZbA0k8mleu6Koucf+BTSvcqRTKBhGS9Iskz/AM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xMOmWHzQ+uXKdLRd5qA7Jq7hghlOD4z2Eep7TpYcZZaD2weilDmjgo8bs7Ul0SIad EXq9wCCoOK2+KhJP7KDQjt+MTas8DHCWZk2qyhzPd2zin48qNA8yW5lFAy1ZhnDh1u 3G6Xhweda/ZBTcnm/ZJSyTfoBmKvrMYN9GdofH1w= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zelin Deng , Brijesh Singh , Wanpeng Li , Paolo Bonzini Subject: [PATCH 5.10 277/290] KVM: kvmclock: Fix vCPUs > 64 cant be online/hotpluged Date: Mon, 15 Mar 2021 15:22:27 +0100 Message-Id: <20210315135551.391322899@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135541.921894249@linuxfoundation.org> References: <20210315135541.921894249@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Greg Kroah-Hartman From: Wanpeng Li commit d7eb79c6290c7ae4561418544072e0a3266e7384 upstream. # lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 88 On-line CPU(s) list: 0-63 Off-line CPU(s) list: 64-87 # cat /proc/cmdline BOOT_IMAGE=/vmlinuz-5.10.0-rc3-tlinux2-0050+ root=/dev/mapper/cl-root ro rd.lvm.lv=cl/root rhgb quiet console=ttyS0 LANG=en_US .UTF-8 no-kvmclock-vsyscall # echo 1 > /sys/devices/system/cpu/cpu76/online -bash: echo: write error: Cannot allocate memory The per-cpu vsyscall pvclock data pointer assigns either an element of the static array hv_clock_boot (#vCPU <= 64) or dynamically allocated memory hvclock_mem (vCPU > 64), the dynamically memory will not be allocated if kvmclock vsyscall is disabled, this can result in cpu hotpluged fails in kvmclock_setup_percpu() which returns -ENOMEM. It's broken for no-vsyscall and sometimes you end up with vsyscall disabled if the host does something strange. This patch fixes it by allocating this dynamically memory unconditionally even if vsyscall is disabled. Fixes: 6a1cac56f4 ("x86/kvm: Use __bss_decrypted attribute in shared variables") Reported-by: Zelin Deng Cc: Brijesh Singh Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li Message-Id: <1614130683-24137-1-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/kvmclock.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -269,21 +269,20 @@ static void __init kvmclock_init_mem(voi static int __init kvm_setup_vsyscall_timeinfo(void) { -#ifdef CONFIG_X86_64 - u8 flags; + kvmclock_init_mem(); - if (!per_cpu(hv_clock_per_cpu, 0) || !kvmclock_vsyscall) - return 0; +#ifdef CONFIG_X86_64 + if (per_cpu(hv_clock_per_cpu, 0) && kvmclock_vsyscall) { + u8 flags; - flags = pvclock_read_flags(&hv_clock_boot[0].pvti); - if (!(flags & PVCLOCK_TSC_STABLE_BIT)) - return 0; + flags = pvclock_read_flags(&hv_clock_boot[0].pvti); + if (!(flags & PVCLOCK_TSC_STABLE_BIT)) + return 0; - kvm_clock.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK; + kvm_clock.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK; + } #endif - kvmclock_init_mem(); - return 0; } early_initcall(kvm_setup_vsyscall_timeinfo);