From patchwork Wed Aug 8 15:55:45 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 10560301 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 41CE514E5 for ; Wed, 8 Aug 2018 15:56:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 301E12B1A9 for ; Wed, 8 Aug 2018 15:56:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 23BCD2B1B0; Wed, 8 Aug 2018 15:56:16 +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 80A702B1A9 for ; Wed, 8 Aug 2018 15:56:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728811AbeHHSQ1 (ORCPT ); Wed, 8 Aug 2018 14:16:27 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42418 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727108AbeHHSQ0 (ORCPT ); Wed, 8 Aug 2018 14:16:26 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2EC517A7E9; Wed, 8 Aug 2018 15:56:09 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.43.2.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id AB57421568A5; Wed, 8 Aug 2018 15:56:06 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org Cc: Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , 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 v4 05/12] KVM: nVMX: implement enlightened VMPTRLD and VMCLEAR Date: Wed, 8 Aug 2018 17:55:45 +0200 Message-Id: <20180808155552.4836-6-vkuznets@redhat.com> In-Reply-To: <20180808155552.4836-1-vkuznets@redhat.com> References: <20180808155552.4836-1-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 08 Aug 2018 15:56:09 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 08 Aug 2018 15:56:09 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'vkuznets@redhat.com' RCPT:'' Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Per Hyper-V TLFS 5.0b: "The L1 hypervisor may choose to use enlightened VMCSs by writing 1 to the corresponding field in the VP assist page (see section 7.8.7). Another field in the VP assist page controls the currently active enlightened VMCS. Each enlightened VMCS is exactly one page (4 KB) in size and must be initially zeroed. No VMPTRLD instruction must be executed to make an enlightened VMCS active or current. After the L1 hypervisor performs a VM entry with an enlightened VMCS, the VMCS is considered active on the processor. An enlightened VMCS can only be active on a single processor at the same time. The L1 hypervisor can execute a VMCLEAR instruction to transition an enlightened VMCS from the active to the non-active state. Any VMREAD or VMWRITE instructions while an enlightened VMCS is active is unsupported and can result in unexpected behavior." Keep Enlightened VMCS structure for the current L2 guest permanently mapped from struct nested_vmx instead of mapping it every time. Suggested-by: Ladi Prosek Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/vmx.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 106 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 50fec04a7d56..47f082db5049 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -20,6 +20,7 @@ #include "mmu.h" #include "cpuid.h" #include "lapic.h" +#include "hyperv.h" #include #include @@ -726,6 +727,8 @@ struct nested_vmx { bool guest_mode; } smm; + gpa_t hv_evmcs_vmptr; + struct page *hv_evmcs_page; struct hv_enlightened_vmcs *hv_evmcs; }; @@ -7890,7 +7893,9 @@ static void nested_vmx_failInvalid(struct kvm_vcpu *vcpu) static void nested_vmx_failValid(struct kvm_vcpu *vcpu, u32 vm_instruction_error) { - if (to_vmx(vcpu)->nested.current_vmptr == -1ull) { + struct vcpu_vmx *vmx = to_vmx(vcpu); + + if (vmx->nested.current_vmptr == -1ull && !vmx->nested.hv_evmcs) { /* * failValid writes the error number to the current VMCS, which * can't be done there isn't a current VMCS. @@ -8223,6 +8228,18 @@ static void vmx_disable_shadow_vmcs(struct vcpu_vmx *vmx) vmcs_write64(VMCS_LINK_POINTER, -1ull); } +static inline void nested_release_evmcs(struct vcpu_vmx *vmx) +{ + if (!vmx->nested.hv_evmcs) + return; + + kunmap(vmx->nested.hv_evmcs_page); + kvm_release_page_dirty(vmx->nested.hv_evmcs_page); + vmx->nested.hv_evmcs_vmptr = -1ull; + vmx->nested.hv_evmcs_page = NULL; + vmx->nested.hv_evmcs = NULL; +} + static inline void nested_release_vmcs12(struct vcpu_vmx *vmx) { if (vmx->nested.current_vmptr == -1ull) @@ -8283,6 +8300,8 @@ static void free_nested(struct vcpu_vmx *vmx) vmx->nested.pi_desc = NULL; } + nested_release_evmcs(vmx); + free_loaded_vmcs(&vmx->nested.vmcs02); } @@ -8319,12 +8338,18 @@ static int handle_vmclear(struct kvm_vcpu *vcpu) return kvm_skip_emulated_instruction(vcpu); } - if (vmptr == vmx->nested.current_vmptr) - nested_release_vmcs12(vmx); + if (vmx->nested.hv_evmcs_page) { + if (vmptr == vmx->nested.hv_evmcs_vmptr) + nested_release_evmcs(vmx); + } else { + if (vmptr == vmx->nested.current_vmptr) + nested_release_vmcs12(vmx); - kvm_vcpu_write_guest(vcpu, - vmptr + offsetof(struct vmcs12, launch_state), - &zero, sizeof(zero)); + kvm_vcpu_write_guest(vcpu, + vmptr + offsetof(struct vmcs12, + launch_state), + &zero, sizeof(zero)); + } nested_vmx_succeed(vcpu); return kvm_skip_emulated_instruction(vcpu); @@ -8415,6 +8440,8 @@ static int copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx) struct vmcs12 *vmcs12 = vmx->nested.cached_vmcs12; struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs; + vmcs12->hdr.revision_id = evmcs->revision_id; + /* HV_VMX_ENLIGHTENED_CLEAN_FIELD_NONE */ vmcs12->tpr_threshold = evmcs->tpr_threshold; vmcs12->guest_rip = evmcs->guest_rip; @@ -9072,6 +9099,10 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) return kvm_skip_emulated_instruction(vcpu); } + /* Forbid normal VMPTRLD if Enlightened version was used */ + if (vmx->nested.hv_evmcs) + return 1; + if (vmx->nested.current_vmptr != vmptr) { struct vmcs12 *new_vmcs12; struct page *page; @@ -9107,6 +9138,68 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) return kvm_skip_emulated_instruction(vcpu); } +/* + * This is an equivalent of the nested hypervisor executing the vmptrld + * instruction. + */ +static int nested_vmx_handle_enlightened_vmptrld(struct kvm_vcpu *vcpu) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + struct hv_vp_assist_page assist_page; + + if (likely(!vmx->nested.enlightened_vmcs_enabled)) + return 1; + + if (unlikely(!kvm_hv_get_assist_page(vcpu, &assist_page))) + return 1; + + if (unlikely(!assist_page.enlighten_vmentry)) + return 1; + + if (unlikely(assist_page.current_nested_vmcs != + vmx->nested.hv_evmcs_vmptr)) { + + if (!vmx->nested.hv_evmcs) + vmx->nested.current_vmptr = -1ull; + + nested_release_evmcs(vmx); + + vmx->nested.hv_evmcs_page = kvm_vcpu_gpa_to_page( + vcpu, assist_page.current_nested_vmcs); + + if (unlikely(is_error_page(vmx->nested.hv_evmcs_page))) + return 0; + + vmx->nested.hv_evmcs = kmap(vmx->nested.hv_evmcs_page); + + if (vmx->nested.hv_evmcs->revision_id != VMCS12_REVISION) { + nested_release_evmcs(vmx); + return 0; + } + + vmx->nested.dirty_vmcs12 = true; + /* + * As we keep L2 state for one guest only 'hv_clean_fields' mask + * can't be used when we switch between them. Reset it here for + * simplicity. + */ + vmx->nested.hv_evmcs->hv_clean_fields &= + ~HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL; + vmx->nested.hv_evmcs_vmptr = assist_page.current_nested_vmcs; + + /* + * Unlike normal vmcs12, enlightened vmcs12 is not fully + * reloaded from guest's memory (read only fields, fields not + * present in struct hv_enlightened_vmcs, ...). Make sure there + * are no leftovers. + */ + memset(vmx->nested.cached_vmcs12, 0, + sizeof(*vmx->nested.cached_vmcs12)); + + } + return 1; +} + /* Emulate the VMPTRST instruction */ static int handle_vmptrst(struct kvm_vcpu *vcpu) { @@ -9118,6 +9211,9 @@ static int handle_vmptrst(struct kvm_vcpu *vcpu) if (!nested_vmx_check_permission(vcpu)) return 1; + if (unlikely(to_vmx(vcpu)->nested.hv_evmcs)) + return 1; + if (get_vmx_mem_address(vcpu, exit_qualification, vmx_instruction_info, true, &vmcs_gva)) return 1; @@ -12697,7 +12793,10 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) if (!nested_vmx_check_permission(vcpu)) return 1; - if (!nested_vmx_check_vmcs12(vcpu)) + if (!nested_vmx_handle_enlightened_vmptrld(vcpu)) + return 1; + + if (!vmx->nested.hv_evmcs && !nested_vmx_check_vmcs12(vcpu)) goto out; vmcs12 = get_vmcs12(vcpu);