Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755695Ab2HSDAu (ORCPT ); Sat, 18 Aug 2012 23:00:50 -0400 Received: from mga11.intel.com ([192.55.52.93]:60723 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753521Ab2HSC5i (ORCPT ); Sat, 18 Aug 2012 22:57:38 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.77,792,1336374000"; d="scan'208";a="210415451" From: Andi Kleen To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, mmarek@suse.cz, linux-kbuild@vger.kernel.org, JBeulich@suse.com, akpm@linux-foundation.org, Andi Kleen , avi@redhat.com Subject: [PATCH 37/74] lto, KVM: Don't assume asm statements end up in the same assembler file Date: Sat, 18 Aug 2012 19:56:33 -0700 Message-Id: <1345345030-22211-38-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1345345030-22211-1-git-send-email-andi@firstfloor.org> References: <1345345030-22211-1-git-send-email-andi@firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2306 Lines: 65 From: Andi Kleen The VMX code references a local assembler label between two inline assembler statements. This assumes they both end up in the same assembler files. In some experimental builds of gcc this is not necessarily true, causing linker failures. Replace the local label reference with a more traditional asmlinkage extern. This also eliminates one assembler statement and generates a bit better code on 64bit: the compiler can use a RIP relative LEA instead of a movabs, saving a few bytes. Cc: avi@redhat.com Signed-off-by: Andi Kleen --- arch/x86/kvm/vmx.c | 10 ++++++---- 1 files changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c00f03d..2fe1de3 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3718,6 +3718,8 @@ static void vmx_disable_intercept_for_msr(u32 msr, bool longmode_only) __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode, msr); } +extern __visible unsigned long kvm_vmx_return; + /* * Set up the vmcs's constant host-state fields, i.e., host-state fields that * will not change in the lifetime of the guest. @@ -3753,8 +3755,7 @@ static void vmx_set_constant_host_state(void) native_store_idt(&dt); vmcs_writel(HOST_IDTR_BASE, dt.address); /* 22.2.4 */ - asm("mov $.Lkvm_vmx_return, %0" : "=r"(tmpl)); - vmcs_writel(HOST_RIP, tmpl); /* 22.2.5 */ + vmcs_writel(HOST_RIP, (unsigned long)&kvm_vmx_return); /* 22.2.5 */ rdmsr(MSR_IA32_SYSENTER_CS, low32, high32); vmcs_write32(HOST_IA32_SYSENTER_CS, low32); @@ -6305,9 +6306,10 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) /* Enter guest mode */ "jne .Llaunched \n\t" __ex(ASM_VMX_VMLAUNCH) "\n\t" - "jmp .Lkvm_vmx_return \n\t" + "jmp kvm_vmx_return \n\t" ".Llaunched: " __ex(ASM_VMX_VMRESUME) "\n\t" - ".Lkvm_vmx_return: " + ".globl kvm_vmx_return\n" + "kvm_vmx_return: " /* Save guest registers, load host registers, keep flags */ "mov %0, %c[wordsize](%%"R"sp) \n\t" "pop %0 \n\t" -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/