From patchwork Mon Jul 31 06:32:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13333731 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 670E8C001DF for ; Mon, 31 Jul 2023 07:02:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230479AbjGaHCb (ORCPT ); Mon, 31 Jul 2023 03:02:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230470AbjGaHCO (ORCPT ); Mon, 31 Jul 2023 03:02:14 -0400 Received: from mgamail.intel.com (unknown [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43F11E7B; Mon, 31 Jul 2023 00:02:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1690786932; x=1722322932; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=lZsnH9xZ+sSI0HJfWdXFi2jVveN7fME2POBe5mQbKKE=; b=J0LdpU5rSmCuBwzkdRgVcfNkCXN4YDZW9i6UpATzZXkMhv3H3dFMbCdL u+CgWOHx4YPkeXuXx6fqMo9KGymbbBnaY6mut4yWQWO/B40B+qroLttVa ShuknVTU1EOwSB0+ih+HfernHtcZhNmBbB27+FxFeoEz0Ge0wGV76Tz3R BmJONRngwVM15yn6k9QjIc/42TGDnty9o1DnAnM9V0B5NzNbUQWxvmDsu JMA5/10NjT5i4UMF6NO4TvZdeWkc3mbYcuuy0Grcs3yIBQNkqTf8gPZLh fZZwOzrJFPuK4aeuajYFSiK7W+1PdMiFwJ+yE1HY3XNplW9ecEwOVqU5a w==; X-IronPort-AV: E=McAfee;i="6600,9927,10787"; a="371648999" X-IronPort-AV: E=Sophos;i="6.01,244,1684825200"; d="scan'208";a="371648999" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jul 2023 00:02:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.01,202,1684825200"; d="scan'208";a="871543400" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 31 Jul 2023 00:02:02 -0700 From: Xin Li To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org Cc: Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Andy Lutomirski , Oleg Nesterov , Tony Luck , "K . Y . Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , Sean Christopherson , Peter Zijlstra , Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , Josh Poimboeuf , "Paul E . McKenney" , Catalin Marinas , Randy Dunlap , Steven Rostedt , Kim Phillips , Xin Li , Hyeonggon Yoo <42.hyeyoo@gmail.com>, "Liam R . Howlett" , Sebastian Reichel , "Kirill A . Shutemov" , Suren Baghdasaryan , Pawan Gupta , Jiaxi Chen , Babu Moger , Jim Mattson , Sandipan Das , Lai Jiangshan , Hans de Goede , Reinette Chatre , Daniel Sneddon , Breno Leitao , Nikunj A Dadhania , Brian Gerst , Sami Tolvanen , Alexander Potapenko , Andrew Morton , Arnd Bergmann , "Eric W . Biederman" , Kees Cook , Masami Hiramatsu , Masahiro Yamada , Ze Gao , Fei Li , Conghui , Ashok Raj , "Jason A . Donenfeld" , Mark Rutland , Jacob Pan , Jiapeng Chong , Jane Malalane , David Woodhouse , Boris Ostrovsky , Arnaldo Carvalho de Melo , Yantengsi , Christophe Leroy , Sathvika Vasireddy Subject: [PATCH v9 12/36] x86/fred: Update MSR_IA32_FRED_RSP0 during task switch Date: Sun, 30 Jul 2023 23:32:53 -0700 Message-Id: <20230731063317.3720-13-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230731063317.3720-1-xin3.li@intel.com> References: <20230731063317.3720-1-xin3.li@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: "H. Peter Anvin (Intel)" MSR_IA32_FRED_RSP0 is used during ring 3 event delivery, and needs to be updated to point to the top of next task stack during task switch. Update MSR_IA32_FRED_RSP0 with WRMSR instruction for now, and will use WRMSRNS/WRMSRLIST for performance once it gets upstreamed. Signed-off-by: H. Peter Anvin (Intel) Tested-by: Shan Kang Signed-off-by: Xin Li --- arch/x86/include/asm/switch_to.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index f42dbf17f52b..6c911fd400b2 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -70,9 +70,16 @@ static inline void update_task_stack(struct task_struct *task) #ifdef CONFIG_X86_32 this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0); #else - /* Xen PV enters the kernel on the thread stack. */ - if (cpu_feature_enabled(X86_FEATURE_XENPV)) + if (cpu_feature_enabled(X86_FEATURE_FRED)) { + /* + * Will use WRMSRNS/WRMSRLIST for performance once it's upstreamed. + */ + wrmsrl(MSR_IA32_FRED_RSP0, + (unsigned long)task_stack_page(task) + THREAD_SIZE); + } else if (cpu_feature_enabled(X86_FEATURE_XENPV)) { + /* Xen PV enters the kernel on the thread stack. */ load_sp0(task_top_of_stack(task)); + } #endif }