From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F2BDC43141 for ; Thu, 21 Jun 2018 12:31:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 293A020837 for ; Thu, 21 Jun 2018 12:31:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 293A020837 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933713AbeFUMbL (ORCPT ); Thu, 21 Jun 2018 08:31:11 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:35722 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933630AbeFUMbE (ORCPT ); Thu, 21 Jun 2018 08:31:04 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 553ED8A3AE; Thu, 21 Jun 2018 12:31:03 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.43.2.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id 606022026D6B; Thu, 21 Jun 2018 12:31:01 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Roman Kagan , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , "Michael Kelley (EOSG)" , Mohammed Gamal , Cathy Avery , linux-kernel@vger.kernel.org, Jim Mattson , Liran Alon Subject: [PATCH v2 6/6] KVM: nVMX: optimize prepare_vmcs02{,_full} for Enlightened VMCS case Date: Thu, 21 Jun 2018 14:30:46 +0200 Message-Id: <20180621123046.29606-7-vkuznets@redhat.com> In-Reply-To: <20180621123046.29606-1-vkuznets@redhat.com> References: <20180621123046.29606-1-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Thu, 21 Jun 2018 12:31:03 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Thu, 21 Jun 2018 12:31:03 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'vkuznets@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When Enlightened VMCS is in use by L1 hypervisor we can avoid vmwriting VMCS fields which did not change. Our first goal is to achieve minimal impact on traditional VMCS case so we're not wrapping each vmwrite() with an if-changed checker. We also can't utilize static keys as Enlightened VMCS usage is per-guest. This patch implements the simpliest solution: checking fields in groups. We skip single vmwrite() statements as doing the check will cost us something even in non-evmcs case and the win is tiny. Unfortunately, this makes prepare_vmcs02_full{,_full}() code Enlightened VMCS-dependent (and a bit ugly). Signed-off-by: Vitaly Kuznetsov --- Changes since v1: - Convert evmcs_needs_write() to inline function [Liran Alon] --- arch/x86/kvm/vmx.c | 158 +++++++++++++++++++++++++++++++---------------------- 1 file changed, 94 insertions(+), 64 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index ea6c651ed477..857fa86c6918 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -11634,47 +11634,82 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne return 0; } +/* + * Check if L1 hypervisor changed the particular field in Enlightened + * VMCS and avoid redundant vmwrite if it didn't. Can only be used when + * the value we're about to write is unchanged vmcs12->field. + */ +static __always_inline bool evmcs_needs_write(struct vcpu_vmx *vmx, + u16 clean_field) +{ + if (vmx->nested.dirty_vmcs12) + return true; + + return !(vmx->nested.hv_evmcs->hv_clean_fields & clean_field); +} + static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) { struct vcpu_vmx *vmx = to_vmx(vcpu); + struct hv_enlightened_vmcs *hv_evmcs = vmx->nested.hv_evmcs; + + if (!hv_evmcs || + evmcs_needs_write(vmx, HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2)) { + vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector); + vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector); + vmcs_write16(GUEST_DS_SELECTOR, vmcs12->guest_ds_selector); + vmcs_write16(GUEST_FS_SELECTOR, vmcs12->guest_fs_selector); + vmcs_write16(GUEST_GS_SELECTOR, vmcs12->guest_gs_selector); + vmcs_write16(GUEST_LDTR_SELECTOR, vmcs12->guest_ldtr_selector); + vmcs_write16(GUEST_TR_SELECTOR, vmcs12->guest_tr_selector); + vmcs_write32(GUEST_ES_LIMIT, vmcs12->guest_es_limit); + vmcs_write32(GUEST_SS_LIMIT, vmcs12->guest_ss_limit); + vmcs_write32(GUEST_DS_LIMIT, vmcs12->guest_ds_limit); + vmcs_write32(GUEST_FS_LIMIT, vmcs12->guest_fs_limit); + vmcs_write32(GUEST_GS_LIMIT, vmcs12->guest_gs_limit); + vmcs_write32(GUEST_LDTR_LIMIT, vmcs12->guest_ldtr_limit); + vmcs_write32(GUEST_TR_LIMIT, vmcs12->guest_tr_limit); + vmcs_write32(GUEST_GDTR_LIMIT, vmcs12->guest_gdtr_limit); + vmcs_write32(GUEST_IDTR_LIMIT, vmcs12->guest_idtr_limit); + vmcs_write32(GUEST_ES_AR_BYTES, vmcs12->guest_es_ar_bytes); + vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes); + vmcs_write32(GUEST_DS_AR_BYTES, vmcs12->guest_ds_ar_bytes); + vmcs_write32(GUEST_FS_AR_BYTES, vmcs12->guest_fs_ar_bytes); + vmcs_write32(GUEST_GS_AR_BYTES, vmcs12->guest_gs_ar_bytes); + vmcs_write32(GUEST_LDTR_AR_BYTES, vmcs12->guest_ldtr_ar_bytes); + vmcs_write32(GUEST_TR_AR_BYTES, vmcs12->guest_tr_ar_bytes); + vmcs_writel(GUEST_SS_BASE, vmcs12->guest_ss_base); + vmcs_writel(GUEST_DS_BASE, vmcs12->guest_ds_base); + vmcs_writel(GUEST_FS_BASE, vmcs12->guest_fs_base); + vmcs_writel(GUEST_GS_BASE, vmcs12->guest_gs_base); + vmcs_writel(GUEST_LDTR_BASE, vmcs12->guest_ldtr_base); + vmcs_writel(GUEST_TR_BASE, vmcs12->guest_tr_base); + vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base); + vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base); + } + + if (!hv_evmcs || + evmcs_needs_write(vmx, HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1)) { + vmcs_write32(GUEST_SYSENTER_CS, vmcs12->guest_sysenter_cs); + vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS, + vmcs12->guest_pending_dbg_exceptions); + vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->guest_sysenter_esp); + vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->guest_sysenter_eip); + + if (vmx_mpx_supported()) + vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs); - vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector); - vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector); - vmcs_write16(GUEST_DS_SELECTOR, vmcs12->guest_ds_selector); - vmcs_write16(GUEST_FS_SELECTOR, vmcs12->guest_fs_selector); - vmcs_write16(GUEST_GS_SELECTOR, vmcs12->guest_gs_selector); - vmcs_write16(GUEST_LDTR_SELECTOR, vmcs12->guest_ldtr_selector); - vmcs_write16(GUEST_TR_SELECTOR, vmcs12->guest_tr_selector); - vmcs_write32(GUEST_ES_LIMIT, vmcs12->guest_es_limit); - vmcs_write32(GUEST_SS_LIMIT, vmcs12->guest_ss_limit); - vmcs_write32(GUEST_DS_LIMIT, vmcs12->guest_ds_limit); - vmcs_write32(GUEST_FS_LIMIT, vmcs12->guest_fs_limit); - vmcs_write32(GUEST_GS_LIMIT, vmcs12->guest_gs_limit); - vmcs_write32(GUEST_LDTR_LIMIT, vmcs12->guest_ldtr_limit); - vmcs_write32(GUEST_TR_LIMIT, vmcs12->guest_tr_limit); - vmcs_write32(GUEST_GDTR_LIMIT, vmcs12->guest_gdtr_limit); - vmcs_write32(GUEST_IDTR_LIMIT, vmcs12->guest_idtr_limit); - vmcs_write32(GUEST_ES_AR_BYTES, vmcs12->guest_es_ar_bytes); - vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes); - vmcs_write32(GUEST_DS_AR_BYTES, vmcs12->guest_ds_ar_bytes); - vmcs_write32(GUEST_FS_AR_BYTES, vmcs12->guest_fs_ar_bytes); - vmcs_write32(GUEST_GS_AR_BYTES, vmcs12->guest_gs_ar_bytes); - vmcs_write32(GUEST_LDTR_AR_BYTES, vmcs12->guest_ldtr_ar_bytes); - vmcs_write32(GUEST_TR_AR_BYTES, vmcs12->guest_tr_ar_bytes); - vmcs_writel(GUEST_SS_BASE, vmcs12->guest_ss_base); - vmcs_writel(GUEST_DS_BASE, vmcs12->guest_ds_base); - vmcs_writel(GUEST_FS_BASE, vmcs12->guest_fs_base); - vmcs_writel(GUEST_GS_BASE, vmcs12->guest_gs_base); - vmcs_writel(GUEST_LDTR_BASE, vmcs12->guest_ldtr_base); - vmcs_writel(GUEST_TR_BASE, vmcs12->guest_tr_base); - vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base); - vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base); - - vmcs_write32(GUEST_SYSENTER_CS, vmcs12->guest_sysenter_cs); - vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS, - vmcs12->guest_pending_dbg_exceptions); - vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->guest_sysenter_esp); - vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->guest_sysenter_eip); + /* + * L1 may access the L2's PDPTR, so save them to construct + * vmcs12 + */ + if (enable_ept) { + vmcs_write64(GUEST_PDPTR0, vmcs12->guest_pdptr0); + vmcs_write64(GUEST_PDPTR1, vmcs12->guest_pdptr1); + vmcs_write64(GUEST_PDPTR2, vmcs12->guest_pdptr2); + vmcs_write64(GUEST_PDPTR3, vmcs12->guest_pdptr3); + } + } if (nested_cpu_has_xsaves(vmcs12)) vmcs_write64(XSS_EXIT_BITMAP, vmcs12->xss_exit_bitmap); @@ -11732,9 +11767,6 @@ static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) set_cr4_guest_host_mask(vmx); - if (vmx_mpx_supported()) - vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs); - if (enable_vpid) { if (nested_cpu_has_vpid(vmcs12) && vmx->nested.vpid02) vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->nested.vpid02); @@ -11742,16 +11774,6 @@ static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->vpid); } - /* - * L1 may access the L2's PDPTR, so save them to construct vmcs12 - */ - if (enable_ept) { - vmcs_write64(GUEST_PDPTR0, vmcs12->guest_pdptr0); - vmcs_write64(GUEST_PDPTR1, vmcs12->guest_pdptr1); - vmcs_write64(GUEST_PDPTR2, vmcs12->guest_pdptr2); - vmcs_write64(GUEST_PDPTR3, vmcs12->guest_pdptr3); - } - if (cpu_has_vmx_msr_bitmap()) vmcs_write64(MSR_BITMAP, __pa(vmx->nested.vmcs02.msr_bitmap)); } @@ -11772,22 +11794,24 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, { struct vcpu_vmx *vmx = to_vmx(vcpu); u32 exec_control, vmcs12_exec_ctrl; + struct hv_enlightened_vmcs *hv_evmcs = vmx->nested.hv_evmcs; - if (vmx->nested.dirty_vmcs12 || vmx->nested.hv_evmcs) { + if (vmx->nested.dirty_vmcs12 || vmx->nested.hv_evmcs) prepare_vmcs02_full(vcpu, vmcs12); - vmx->nested.dirty_vmcs12 = false; - } /* * First, the fields that are shadowed. This must be kept in sync * with vmx_shadow_fields.h. */ - vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector); - vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit); - vmcs_write32(GUEST_CS_AR_BYTES, vmcs12->guest_cs_ar_bytes); - vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base); - vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base); + if (!hv_evmcs || + evmcs_needs_write(vmx, HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2)) { + vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector); + vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit); + vmcs_write32(GUEST_CS_AR_BYTES, vmcs12->guest_cs_ar_bytes); + vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base); + vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base); + } /* * Not in vmcs02: GUEST_PML_INDEX, HOST_FS_SELECTOR, HOST_GS_SELECTOR, @@ -11803,12 +11827,15 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, vmcs_write64(GUEST_IA32_DEBUGCTL, vmx->nested.vmcs01_debugctl); } if (vmx->nested.nested_run_pending) { - vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, - vmcs12->vm_entry_intr_info_field); - vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, - vmcs12->vm_entry_exception_error_code); - vmcs_write32(VM_ENTRY_INSTRUCTION_LEN, - vmcs12->vm_entry_instruction_len); + if (!hv_evmcs || evmcs_needs_write(vmx, + HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_EVENT)) { + vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, + vmcs12->vm_entry_intr_info_field); + vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, + vmcs12->vm_entry_exception_error_code); + vmcs_write32(VM_ENTRY_INSTRUCTION_LEN, + vmcs12->vm_entry_instruction_len); + } vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, vmcs12->guest_interruptibility_info); vmx->loaded_vmcs->nmi_known_unmasked = @@ -12032,6 +12059,9 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, kvm_register_write(vcpu, VCPU_REGS_RSP, vmcs12->guest_rsp); kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->guest_rip); + + vmx->nested.dirty_vmcs12 = false; + return 0; } -- 2.14.4