From patchwork Tue Dec 20 06:36:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13077546 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 789F7C4332F for ; Tue, 20 Dec 2022 07:02:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233430AbiLTHCu (ORCPT ); Tue, 20 Dec 2022 02:02:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233284AbiLTHBn (ORCPT ); Tue, 20 Dec 2022 02:01:43 -0500 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BED616486; Mon, 19 Dec 2022 23:01:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1671519699; x=1703055699; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TP8n9pSqR9d/xRUDBC0wSmLuk1j6QLJ8duTmvudCB0o=; b=a6fcbdcH8dy0QBrarpcl7TcMNcyf3uvfacmtICPy340s8gAWo+0Zpl75 ECNaPzGkh7O5TMF/e0KEvcYHzBiunO8Tp1Z1oLsHvZh/oZH5/5chnzgi9 bJ9xtCx+j+qEHaxuizUj1XD8BxBXWL/3/5rFMVK+R/ybDe8065Fj+/mRF uFw17yu3wkyZGt01HhXDUYS7TTWeY3PVbRN8/CFIJzt2WUvYSfyRbxzo2 c5PnMzT+X9AJsBFpziEPwTBftCI1gXW5xcsUzEwN7HyKOXIptwv3hGdny ug/67oIGW4/edNN1fg+h4dxGAYDYmIYCpPbYKmFj0bjsOxKCRItAJQFjL g==; X-IronPort-AV: E=McAfee;i="6500,9779,10566"; a="302972109" X-IronPort-AV: E=Sophos;i="5.96,258,1665471600"; d="scan'208";a="302972109" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Dec 2022 23:01:17 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10566"; a="644326522" X-IronPort-AV: E=Sophos;i="5.96,258,1665471600"; d="scan'208";a="644326522" Received: from unknown (HELO fred..) ([172.25.112.68]) by orsmga007.jf.intel.com with ESMTP; 19 Dec 2022 23:01:17 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH 23/32] x86/fred: update MSR_IA32_FRED_RSP0 during task switch Date: Mon, 19 Dec 2022 22:36:49 -0800 Message-Id: <20221220063658.19271-24-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221220063658.19271-1-xin3.li@intel.com> References: <20221220063658.19271-1-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. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/switch_to.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index c08eb0fdd11f..c28170d4fbba 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -71,9 +71,13 @@ static inline void update_task_stack(struct task_struct *task) else this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0); #else - /* Xen PV enters the kernel on the thread stack. */ - if (static_cpu_has(X86_FEATURE_XENPV)) + if (cpu_feature_enabled(X86_FEATURE_FRED)) { + wrmsrl(MSR_IA32_FRED_RSP0, + task_top_of_stack(task) + TOP_OF_KERNEL_STACK_PADDING); + } else if (static_cpu_has(X86_FEATURE_XENPV)) { + /* Xen PV enters the kernel on the thread stack. */ load_sp0(task_top_of_stack(task)); + } #endif }