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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36945C433EF for ; Wed, 10 Nov 2021 11:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B8DD6115B for ; Wed, 10 Nov 2021 11:59:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231789AbhKJMCg (ORCPT ); Wed, 10 Nov 2021 07:02:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231760AbhKJMCd (ORCPT ); Wed, 10 Nov 2021 07:02:33 -0500 Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80A29C061764 for ; Wed, 10 Nov 2021 03:59:46 -0800 (PST) Received: by mail-pf1-x42e.google.com with SMTP id b68so2430234pfg.11 for ; Wed, 10 Nov 2021 03:59:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=z9SEfT4DE6G7poVIoOZ/2F9cmvyRyv0Yaov7+rhnIBU=; b=FvzZqtoRPuJ96HdFxbZ070TPkPA+N1wyesrajcAp0bpBz3qAo1/NW0LsvlFj/Foeda yKrtnY81VzdKwMapF+7CmSlCMuy4+wNSqLwVcE9G0A/8Umq6IpNF6jblYJWjYH+hiHWo /RCktA1dtQsRH5y7HXPI/dro6xp5qW6NUg2Xq0RKSp4ND0XIvixzq4kdL0CGD9hQURRW b9DcEDN9jspMVkU1Jymg2JTv+qs1UgClt7TvWUXtjNzdIkECry4Nff0/oJzhloXqhCAO 3/a0UZuDWlSGdHoQEBcDB0vlAJ93vYZQ3aJidmoUe8h7r8h/zX90TwXSunryDuJSxvty lGVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=z9SEfT4DE6G7poVIoOZ/2F9cmvyRyv0Yaov7+rhnIBU=; b=ymATt/cGOwupfZiqT/jM3Kerdmdg4N0t4RZ4MKUe5PJ5cRP+PZDR6Et0Y1eYCvvS+R 0erJkTLRFaz5fr7Dm3FX7IV8WQVKDNGX9H4rYGtToswZKSHdwLDYR/dC87zhf2qkKBqW RZvrma/Pfhfuw3F+rxGpqxm9bw5HJyu52K5h/Vkzim+ZePVSJ9UkTEOssbS5HTXugfQe DAWdpsPG3B2gSkGJgfek/EnnvPbU+VgZeep/w7K5edSX4kXpAU/nqtUdl+T81vTfKKGI WkVRDWl/Xd5RYeT7IiCSihI61yP4G23wHyRJJJYaUPAG6nr5notvtGTDvhkUvk/Ss2Ke dBEg== X-Gm-Message-State: AOAM530/0QqtxIWB9PYZ6StOeoq5MNuhdDQQogvl6r9TNSE5BKQAl3pu JPGgyxp9cILmBDp7Qwg2weiKzU6uaMI= X-Google-Smtp-Source: ABdhPJzKjAa9q/y1ix1CgtDel8UNShHIygeqPwUrb2lFZocBDmhzy7lE2r0hp04rUGUQB9+wXg4nxA== X-Received: by 2002:a63:ff04:: with SMTP id k4mr11188732pgi.309.1636545585915; Wed, 10 Nov 2021 03:59:45 -0800 (PST) Received: from localhost ([198.11.178.15]) by smtp.gmail.com with ESMTPSA id lw1sm6007564pjb.38.2021.11.10.03.59.45 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 10 Nov 2021 03:59:45 -0800 (PST) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, Lai Jiangshan , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Subject: [PATCH V5 22/50] x86/entry: Don't call error_entry for XENPV Date: Wed, 10 Nov 2021 19:57:08 +0800 Message-Id: <20211110115736.3776-23-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20211110115736.3776-1-jiangshanlai@gmail.com> References: <20211110115736.3776-1-jiangshanlai@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lai Jiangshan When in XENPV, it is already in the task stack, and it can't fault at native_irq_return_iret nor asm_load_gs_index_gs_change since XENPV uses its own pvops for iret and load_gs_index(). And it doesn't need to switch CR3. So it can skip invoking error_entry(). Signed-off-by: Lai Jiangshan --- arch/x86/entry/entry_64.S | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 74c82fb01d36..2f3883d92536 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -325,8 +325,17 @@ SYM_CODE_END(ret_from_fork) PUSH_AND_CLEAR_REGS ENCODE_FRAME_POINTER - call error_entry - movq %rax, %rsp /* switch stack settled by sync_regs() */ + /* + * Call error_entry and switch stack settled by sync_regs(). + * + * When in XENPV, it is already in the task stack, and it can't fault + * at native_irq_return_iret nor asm_load_gs_index_gs_change since + * XENPV uses its own pvops for iret and load_gs_index(). And it + * doesn't need to switch CR3. So it can skip invoking error_entry(). + */ + ALTERNATIVE "call error_entry; movq %rax, %rsp", \ + "", X86_FEATURE_XENPV + ENCODE_FRAME_POINTER UNWIND_HINT_REGS -- 2.19.1.6.gb485710b