From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754038AbXLZLMz (ORCPT ); Wed, 26 Dec 2007 06:12:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751863AbXLZLGg (ORCPT ); Wed, 26 Dec 2007 06:06:36 -0500 Received: from il.qumranet.com ([82.166.9.18]:50479 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751704AbXLZLGF (ORCPT ); Wed, 26 Dec 2007 06:06:05 -0500 From: Avi Kivity To: linux-kernel@vger.kernel.org, kvm-devel@lists.sourceforge.net Cc: Laurent Vivier Subject: [PATCH 14/55] KVM: SVM: Let gcc to choose which registers to save (i386) Date: Wed, 26 Dec 2007 13:05:19 +0200 Message-Id: <1198667160-22953-15-git-send-email-avi@qumranet.com> X-Mailer: git-send-email 1.5.3.7 In-Reply-To: <1198667160-22953-1-git-send-email-avi@qumranet.com> References: <1198667160-22953-1-git-send-email-avi@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Laurent Vivier This patch lets GCC to determine which registers to save when we switch to/from a VCPU in the case of AMD i386 * Original code saves following registers: ebx, ecx, edx, esi, edi, ebp * Patched code: - informs GCC that we modify following registers using the clobber description: ebx, ecx, edx, esi, edi - rbp is saved (pop/push) because GCC seems to ignore its use in the clobber description. Signed-off-by: Laurent Vivier Signed-off-by: Avi Kivity --- drivers/kvm/svm.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c index 1298bde..cdd4fd2 100644 --- a/drivers/kvm/svm.c +++ b/drivers/kvm/svm.c @@ -1501,8 +1501,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) #ifdef CONFIG_X86_64 "push %%rbp; \n\t" #else - "push %%ebx; push %%ecx; push %%edx;" - "push %%esi; push %%edi; push %%ebp;" + "push %%ebp; \n\t" #endif #ifdef CONFIG_X86_64 @@ -1573,8 +1572,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) "mov %%edi, %c[rdi](%[svm]) \n\t" "mov %%ebp, %c[rbp](%[svm]) \n\t" - "pop %%ebp; pop %%edi; pop %%esi;" - "pop %%edx; pop %%ecx; pop %%ebx; \n\t" + "pop %%ebp; \n\t" #endif : : [svm]"a"(svm), @@ -1599,6 +1597,8 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) #ifdef CONFIG_X86_64 , "rbx", "rcx", "rdx", "rsi", "rdi" , "r8", "r9", "r10", "r11" , "r12", "r13", "r14", "r15" +#else + , "ebx", "ecx", "edx" , "esi", "edi" #endif ); -- 1.5.3.7