From patchwork Thu Jan 24 17:58:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 10779731 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0A9C9139A for ; Thu, 24 Jan 2019 17:59:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F1F5331B9D for ; Thu, 24 Jan 2019 17:59:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E446B31BBB; Thu, 24 Jan 2019 17:59:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE28131B9D for ; Thu, 24 Jan 2019 17:59:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729256AbfAXR7I (ORCPT ); Thu, 24 Jan 2019 12:59:08 -0500 Received: from mga02.intel.com ([134.134.136.20]:19131 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729223AbfAXR7G (ORCPT ); Thu, 24 Jan 2019 12:59:06 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Jan 2019 09:59:02 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,517,1539673200"; d="scan'208";a="110775889" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.14]) by orsmga006.jf.intel.com with ESMTP; 24 Jan 2019 09:59:01 -0800 From: Sean Christopherson To: Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= Cc: kvm@vger.kernel.org, Jim Mattson , Konrad Rzeszutek Wilk Subject: [PATCH v2 13/29] KVM: nVMX: Let the compiler select the reg for holding HOST_RSP Date: Thu, 24 Jan 2019 09:58:30 -0800 Message-Id: <20190124175845.15926-14-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124175845.15926-1-sean.j.christopherson@intel.com> References: <20190124175845.15926-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP ...and provide an explicit name for the constraint. Naming the input constraint makes the code self-documenting and also avoids the fragility of numerically referring to constraints, e.g. %4 breaks badly whenever the constraints are modified. Explicitly using RDX was inherited from vCPU-run, i.e. completely arbitrary. Even vCPU-run doesn't truly need to explicitly use RDX, but doing so is more robust as vCPU-run needs tight control over its register usage. Note that while the naming "conflict" between host_rsp and HOST_RSP is slightly confusing, the former will be renamed slightly in a future patch, at which point HOST_RSP is absolutely what is desired. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/nested.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index d42134f836a6..48281b0684ca 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2752,9 +2752,8 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) } asm( - /* Set HOST_RSP */ "sub $%c[wordsize], %%" _ASM_SP "\n\t" /* temporarily adjust RSP for CALL */ - __ex("vmwrite %%" _ASM_SP ", %%" _ASM_DX) "\n\t" + __ex("vmwrite %%" _ASM_SP ", %[HOST_RSP]") "\n\t" "mov %%" _ASM_SP ", %c[host_rsp](%% " _ASM_CX ")\n\t" "add $%c[wordsize], %%" _ASM_SP "\n\t" /* un-adjust RSP */ @@ -2771,7 +2770,8 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) CC_SET(be) : ASM_CALL_CONSTRAINT, CC_OUT(be) (vm_fail) - : "c"(vmx), "d"((unsigned long)HOST_RSP), + : "c"(vmx), + [HOST_RSP]"r"((unsigned long)HOST_RSP), [loaded_vmcs]"r"(vmx->loaded_vmcs), [launched]"i"(offsetof(struct loaded_vmcs, launched)), [host_rsp]"i"(offsetof(struct vcpu_vmx, host_rsp)),