From patchwork Wed Aug 17 14:40:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Uros Bizjak X-Patchwork-Id: 12945996 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 0B18FC25B08 for ; Wed, 17 Aug 2022 14:41:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240246AbiHQOlY (ORCPT ); Wed, 17 Aug 2022 10:41:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239736AbiHQOk7 (ORCPT ); Wed, 17 Aug 2022 10:40:59 -0400 Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A44139AF93; Wed, 17 Aug 2022 07:40:58 -0700 (PDT) Received: by mail-ej1-x62c.google.com with SMTP id i14so24879770ejg.6; Wed, 17 Aug 2022 07:40:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc; bh=OYkBi6IJIzT1jwPLplqfUttZv3Vgq/u2jaSOjLFpJqA=; b=fwDyeTpkUcetEWKRjH4bzYDwOaTQUwQp3IKoqtDHu9n1ny1MRYQ74w/yg+sIyc4FGA aTjJX+U6lQsZQD0qLsMnbvQzn1lbTYAhKT1fGdR4CViBfodvfer1yIUmMW/yBZg0AyJi R4UyIHsOqjrNUAHWjdQvdhoEOCEWDMaP4kDX7dVGDyI3pPOf2FlBE9AA5rPFEaAtmxLg b4EEQqgdmQwAio8RJntfcOJ2SD9E32KDuriwmPpogKqTgEKY1a12pXtzuRwbXsDVRkJF 5HGUxLiAW7biRK/8fx9vlf+C2F8ZSH9k6b/iZEuKhGbf8hzV0i3l3uwHBauELv/IvU6Y wDCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc; bh=OYkBi6IJIzT1jwPLplqfUttZv3Vgq/u2jaSOjLFpJqA=; b=qrw4HcnDWmAT/QxHIfFzXagTyUSg8C77hCaMUKv60UcksYtu4flFL3qk/e4hcTWlNi Jle1xh3UdgPGmVCZq+O0mrj4SGxDTXSVUWWu6A4CZ0PmQlJMDAh3GaUYMeXSHDL7iDCx 4HAd7896xucaix/BsZfvrOjffxIP+WXaaRsAuqADQaBPlg9+66MSz2ovXmOIzqLLXhMj /x1I5jVdKrioPu0reqfqKjJ8DsL1Oc+LJY8xQGzAbDPY6fj2dJfs2HRlN4QmFrupi1rQ nTXUFN/2dXhjGlVYc1eJnfp1OoMqN/hmd2nIAVVNR3WHcQVL5pNgN6VCBhhmjRffT3jb /WyQ== X-Gm-Message-State: ACgBeo0D9Ovqj3xa2ee2ODcYGY4f1CAm3nhXmvCNGqibasTv3PSMEGH6 MveBrjgbhJEzO9LO5KKgjb5Pfd1GxJME5A== X-Google-Smtp-Source: AA6agR6efll/+5JYLS49lp5cCBPRwxMOs5NUeZQlmZF9pliBgu0d7BNxwtlXbM4emxEL8TSresvj9A== X-Received: by 2002:a17:907:2da6:b0:730:8b30:e517 with SMTP id gt38-20020a1709072da600b007308b30e517mr17074250ejc.291.1660747256817; Wed, 17 Aug 2022 07:40:56 -0700 (PDT) Received: from localhost.localdomain ([46.248.82.114]) by smtp.gmail.com with ESMTPSA id hr16-20020a1709073f9000b007317ad372c0sm6800199ejc.20.2022.08.17.07.40.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Aug 2022 07:40:56 -0700 (PDT) From: Uros Bizjak To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Uros Bizjak , Paolo Bonzini , Sean Christopherson Subject: [PATCH] KVM/VMX: Do not declare vmread_error asmlinkage Date: Wed, 17 Aug 2022 16:40:45 +0200 Message-Id: <20220817144045.3206-1-ubizjak@gmail.com> X-Mailer: git-send-email 2.37.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org There is no need to declare vmread_error asmlinkage, its arguments can be passed via registers for both, 32-bit and 64-bit targets. Function argument registers are considered call-clobbered registers, they are saved in the trampoline just before the function call and restored afterwards. Note that asmlinkage and __attribute__((regparm(0))) have no effect on 64-bit targets. The trampoline is called from the assembler glue code that implements its own stack-passing function calling convention, so the attribute on the trampoline declaration does not change anything for 64-bit as well as 32-bit targets. We can declare it asmlinkage for documentation purposes. The patch unifies trampoline function argument handling between 32-bit and 64-bit targets and improves generated code for 32-bit targets. Cc: Paolo Bonzini Cc: Sean Christopherson Signed-off-by: Uros Bizjak Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmenter.S | 15 +++------------ arch/x86/kvm/vmx/vmx.c | 2 +- arch/x86/kvm/vmx/vmx_ops.h | 6 +++--- 3 files changed, 7 insertions(+), 16 deletions(-) diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S index 6de96b943804..2b83bab6e371 100644 --- a/arch/x86/kvm/vmx/vmenter.S +++ b/arch/x86/kvm/vmx/vmenter.S @@ -293,22 +293,13 @@ SYM_FUNC_START(vmread_error_trampoline) push %r10 push %r11 #endif -#ifdef CONFIG_X86_64 + /* Load @field and @fault to arg1 and arg2 respectively. */ - mov 3*WORD_SIZE(%rbp), %_ASM_ARG2 - mov 2*WORD_SIZE(%rbp), %_ASM_ARG1 -#else - /* Parameters are passed on the stack for 32-bit (see asmlinkage). */ - push 3*WORD_SIZE(%ebp) - push 2*WORD_SIZE(%ebp) -#endif + mov 3*WORD_SIZE(%_ASM_BP), %_ASM_ARG2 + mov 2*WORD_SIZE(%_ASM_BP), %_ASM_ARG1 call vmread_error -#ifndef CONFIG_X86_64 - add $8, %esp -#endif - /* Zero out @fault, which will be popped into the result register. */ _ASM_MOV $0, 3*WORD_SIZE(%_ASM_BP) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index d7f8331d6f7e..c940688ceaa4 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -439,7 +439,7 @@ do { \ pr_warn_ratelimited(fmt); \ } while (0) -asmlinkage void vmread_error(unsigned long field, bool fault) +void vmread_error(unsigned long field, bool fault) { if (fault) kvm_spurious_fault(); diff --git a/arch/x86/kvm/vmx/vmx_ops.h b/arch/x86/kvm/vmx/vmx_ops.h index 5cfc49ddb1b4..550a89394d9f 100644 --- a/arch/x86/kvm/vmx/vmx_ops.h +++ b/arch/x86/kvm/vmx/vmx_ops.h @@ -10,9 +10,9 @@ #include "vmcs.h" #include "../x86.h" -asmlinkage void vmread_error(unsigned long field, bool fault); -__attribute__((regparm(0))) void vmread_error_trampoline(unsigned long field, - bool fault); +void vmread_error(unsigned long field, bool fault); +asmlinkage void vmread_error_trampoline(unsigned long field, + bool fault); void vmwrite_error(unsigned long field, unsigned long value); void vmclear_error(struct vmcs *vmcs, u64 phys_addr); void vmptrld_error(struct vmcs *vmcs, u64 phys_addr);