From patchwork Fri Jan 25 15:40:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 10781609 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 3ACE41515 for ; Fri, 25 Jan 2019 15:42:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2A04E2F750 for ; Fri, 25 Jan 2019 15:42:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1E9102F7C2; Fri, 25 Jan 2019 15:42:29 +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 B5EC32F750 for ; Fri, 25 Jan 2019 15:42:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729136AbfAYPm0 (ORCPT ); Fri, 25 Jan 2019 10:42:26 -0500 Received: from mga09.intel.com ([134.134.136.24]:54653 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727826AbfAYPlt (ORCPT ); Fri, 25 Jan 2019 10:41:49 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jan 2019 07:41:46 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,521,1539673200"; d="scan'208";a="128877873" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.14]) by orsmga002.jf.intel.com with ESMTP; 25 Jan 2019 07:41:46 -0800 From: Sean Christopherson To: Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= Cc: kvm@vger.kernel.org, Jim Mattson , Konrad Rzeszutek Wilk Subject: [PATCH v3 06/33] KVM: VMX: Manually load RDX in vCPU-run asm blob Date: Fri, 25 Jan 2019 07:40:53 -0800 Message-Id: <20190125154120.19385-7-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190125154120.19385-1-sean.j.christopherson@intel.com> References: <20190125154120.19385-1-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 Load RDX with the VMCS.HOST_RSP field encoding on-demand instead of delegating to the compiler via an input constraint. In addition to saving one whole MOV instruction, this allows RDX to be properly clobbered (in a future patch) instead of being saved/loaded to/from the stack. Despite nested_vmx_check_vmentry_hw() having similar code, leave it alone, for now. In that case, RDX is unconditionally used and isn't clobbered, i.e. sending in HOST_RSP as an input is simpler. Note that because HOST_RSP is an enum and not a define, it must be redefined as an immediate instead of using __stringify(HOST_RSP). The naming "conflict" between host_rsp and HOST_RSP is slightly confusing, but the former will be removed in a future patch, at which point HOST_RSP is absolutely what is desired. Reviewed-by: Jim Mattson Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 6f3cd19cbe3a..5dcd38a74ef4 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6389,6 +6389,7 @@ static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx) "mov %%" _ASM_SP ", (%%" _ASM_SI ") \n\t" "jmp 1f \n\t" "2: \n\t" + "mov $%c[HOST_RSP], %%" _ASM_DX " \n\t" __ex("vmwrite %%" _ASM_SP ", %%" _ASM_DX) "\n\t" "1: \n\t" "add $%c[wordsize], %%" _ASM_SP "\n\t" /* un-adjust RSP */ @@ -6481,10 +6482,11 @@ static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx) "xor %%ebp, %%ebp \n\t" "pop %%" _ASM_BP "; pop %%" _ASM_DX " \n\t" : ASM_CALL_CONSTRAINT, "=S"((int){0}) - : "c"(vmx), "d"((unsigned long)HOST_RSP), "S"(evmcs_rsp), + : "c"(vmx), "S"(evmcs_rsp), [launched]"i"(offsetof(struct vcpu_vmx, __launched)), [fail]"i"(offsetof(struct vcpu_vmx, fail)), [host_rsp]"i"(offsetof(struct vcpu_vmx, host_rsp)), + [HOST_RSP]"i"(HOST_RSP), [rax]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RAX])), [rbx]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RBX])), [rcx]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RCX])),