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 6335EC433EF for ; Tue, 26 Oct 2021 14:30:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4283961152 for ; Tue, 26 Oct 2021 14:30:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236680AbhJZOdI (ORCPT ); Tue, 26 Oct 2021 10:33:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236655AbhJZOdH (ORCPT ); Tue, 26 Oct 2021 10:33:07 -0400 Received: from mail-pf1-x433.google.com (mail-pf1-x433.google.com [IPv6:2607:f8b0:4864:20::433]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A760C061767 for ; Tue, 26 Oct 2021 07:30:44 -0700 (PDT) Received: by mail-pf1-x433.google.com with SMTP id t184so14549370pfd.0 for ; Tue, 26 Oct 2021 07:30:44 -0700 (PDT) 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=NquEC0oc8qAgKVZRz/dm1+f35RYA3XM4ByaTUaAorok=; b=Kg1ymFDRZxwrj2Xbp+PfPILSwFO0XLIH656yvwz2AgqQjsMuzGFZsZ83ttpWFfJ0R+ nxcaUuUiaQAZtbIhuWF5oxZok1vJtb9TbhXtir38Y/jXAebB88GiMB8olfu0OOMp5W7O ug9DIHntq876f/DFwiSyWoGmNteLqzihNOJtaHMigaKEVmPUYjRHj2VzCei+459jnp2z vwIQt+oyzdqXGb8ZQ079+3xwcFfw6HlLO9eEk4ACyuFTKk8hHwSsCbt3fF3khFBdwk5G +XFz2FotpT6wq8KyWuFktDn5eC8yI22FhpiCC/0LdRo7uM88bvptvlzj/8pYKoZn8whu tDpA== 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=NquEC0oc8qAgKVZRz/dm1+f35RYA3XM4ByaTUaAorok=; b=wjsH4xjFfXm33eA/PuLIPmEijydYoGFp0c12VLLdpGWfkpDbpeOVWMH75FAjvQhrVk rOlN/bM8ztm4TtvnmMKgfvX307BCpZzElOY2gANNgHmBqDh/+nOTqtowYcQvtosjSTrb 0aXr+2coZFImL8CcXXMHS+8qhaCg/eHniv0feI1j9kvS8SCtgcwxp1Glod0fQtsJBVow obfYYgmZrxv94N0vtmQ9I0xZq2XqaIsHjcBAXZ280Yo1Nd6JwhhN8TiFJfxdc9lQqajR ZKNA1vL6peQ4abz9W3vtzYIISvTb4zx780tm+hqXlCXOpN52gsOR6tLK/Lddxdsl1EvU q6gg== X-Gm-Message-State: AOAM5336yHwOd4dkSuNIeGoCV8yu+B0zF2vCKPi1+CffGBg3vhrhKQ8k HoM5ckwhMNhgh4j7nQrfPKerBSRGVus= X-Google-Smtp-Source: ABdhPJxMki/vC5GM4sUYaoso1OQo3LdcNm7B+9xOTw8IPIyBZWfpNCmpwTKeJYT0rgzcGU15WAccZA== X-Received: by 2002:a63:8ac7:: with SMTP id y190mr11124582pgd.55.1635258643611; Tue, 26 Oct 2021 07:30:43 -0700 (PDT) Received: from localhost ([47.88.5.130]) by smtp.gmail.com with ESMTPSA id il17sm1085323pjb.52.2021.10.26.07.30.41 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Oct 2021 07:30:42 -0700 (PDT) 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 V4 22/50] x86/entry: Don't call error_entry for XENPV Date: Tue, 26 Oct 2021 22:30:04 +0800 Message-Id: <20211026143032.18624-4-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20211026141420.17138-1-jiangshanlai@gmail.com> References: <20211026141420.17138-1-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 52a08c4a0171..9bad620553c8 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -326,8 +326,17 @@ 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