From patchwork Wed Sep 29 15:53:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joerg Roedel X-Patchwork-Id: 12525855 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91C11C433EF for ; Wed, 29 Sep 2021 15:53:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 729A3613A7 for ; Wed, 29 Sep 2021 15:53:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345427AbhI2PzZ (ORCPT ); Wed, 29 Sep 2021 11:55:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35416 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344105AbhI2PzU (ORCPT ); Wed, 29 Sep 2021 11:55:20 -0400 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78EC6C061760; Wed, 29 Sep 2021 08:53:39 -0700 (PDT) Received: from cap.home.8bytes.org (p4ff2b5b0.dip0.t-ipconnect.de [79.242.181.176]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by theia.8bytes.org (Postfix) with ESMTPSA id 1C6ECFC7; Wed, 29 Sep 2021 17:53:37 +0200 (CEST) From: Joerg Roedel To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , x86@kernel.org, Brijesh Singh , Tom Lendacky , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Joerg Roedel Subject: [PATCH v4 3/5] KVM: SVM: Add support to handle AP reset MSR protocol Date: Wed, 29 Sep 2021 17:53:28 +0200 Message-Id: <20210929155330.5597-4-joro@8bytes.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210929155330.5597-1-joro@8bytes.org> References: <20210929155330.5597-1-joro@8bytes.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Tom Lendacky Add support for AP Reset Hold being invoked using the GHCB MSR protocol, available in version 2 of the GHCB specification. Signed-off-by: Tom Lendacky Signed-off-by: Brijesh Singh Signed-off-by: Joerg Roedel --- arch/x86/include/asm/kvm_host.h | 10 ++++++- arch/x86/kvm/svm/sev.c | 48 ++++++++++++++++++++++++++------- arch/x86/kvm/x86.c | 5 +++- 3 files changed, 51 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 88f0326c184a..501a55cecd73 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -237,6 +237,11 @@ enum x86_intercept_stage; KVM_GUESTDBG_INJECT_DB | \ KVM_GUESTDBG_BLOCKIRQ) +enum ap_reset_hold_type { + AP_RESET_HOLD_NONE, + AP_RESET_HOLD_NAE_EVENT, + AP_RESET_HOLD_MSR_PROTO, +}; #define PFERR_PRESENT_BIT 0 #define PFERR_WRITE_BIT 1 @@ -908,6 +913,8 @@ struct kvm_vcpu_arch { #if IS_ENABLED(CONFIG_HYPERV) hpa_t hv_root_tdp; #endif + + enum ap_reset_hold_type reset_hold_type; }; struct kvm_lpage_info { @@ -1690,7 +1697,8 @@ int kvm_fast_pio(struct kvm_vcpu *vcpu, int size, unsigned short port, int in); int kvm_emulate_cpuid(struct kvm_vcpu *vcpu); int kvm_emulate_halt(struct kvm_vcpu *vcpu); int kvm_vcpu_halt(struct kvm_vcpu *vcpu); -int kvm_emulate_ap_reset_hold(struct kvm_vcpu *vcpu); +int kvm_emulate_ap_reset_hold(struct kvm_vcpu *vcpu, + enum ap_reset_hold_type type); int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu); void kvm_get_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg); diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 159b22bb74e4..69653d7838e3 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2246,6 +2246,9 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm) void sev_es_unmap_ghcb(struct vcpu_svm *svm) { + /* Clear any indication that the vCPU is in a type of AP Reset Hold */ + svm->vcpu.arch.reset_hold_type = AP_RESET_HOLD_NONE; + if (!svm->ghcb) return; @@ -2405,6 +2408,11 @@ static u64 ghcb_msr_version_info(void) return msr; } +static u64 ghcb_msr_ap_rst_resp(u64 value) +{ + return (u64)GHCB_MSR_AP_RESET_HOLD_RESP | (value << GHCB_DATA_LOW); +} + static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm) { struct vmcb_control_area *control = &svm->vmcb->control; @@ -2451,6 +2459,16 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm) break; } + case GHCB_MSR_AP_RESET_HOLD_REQ: + ret = kvm_emulate_ap_reset_hold(&svm->vcpu, AP_RESET_HOLD_MSR_PROTO); + + /* + * Preset the result to a non-SIPI return and then only set + * the result to non-zero when delivering a SIPI. + */ + svm->vmcb->control.ghcb_gpa = ghcb_msr_ap_rst_resp(0); + + break; case GHCB_MSR_TERM_REQ: { u64 reason_set, reason_code; @@ -2536,7 +2554,7 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) ret = svm_invoke_exit_handler(vcpu, SVM_EXIT_IRET); break; case SVM_VMGEXIT_AP_HLT_LOOP: - ret = kvm_emulate_ap_reset_hold(vcpu); + ret = kvm_emulate_ap_reset_hold(vcpu, AP_RESET_HOLD_NAE_EVENT); break; case SVM_VMGEXIT_AP_JUMP_TABLE: { struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info; @@ -2671,13 +2689,23 @@ void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector) return; } - /* - * Subsequent SIPI: Return from an AP Reset Hold VMGEXIT, where - * the guest will set the CS and RIP. Set SW_EXIT_INFO_2 to a - * non-zero value. - */ - if (!svm->ghcb) - return; - - ghcb_set_sw_exit_info_2(svm->ghcb, 1); + /* Subsequent SIPI */ + switch (vcpu->arch.reset_hold_type) { + case AP_RESET_HOLD_NAE_EVENT: + /* + * Return from an AP Reset Hold VMGEXIT, where the guest will + * set the CS and RIP. Set SW_EXIT_INFO_2 to a non-zero value. + */ + ghcb_set_sw_exit_info_2(svm->ghcb, 1); + break; + case AP_RESET_HOLD_MSR_PROTO: + /* + * Return from an AP Reset Hold VMGEXIT, where the guest will + * set the CS and RIP. Set GHCB data field to a non-zero value. + */ + svm->vmcb->control.ghcb_gpa = ghcb_msr_ap_rst_resp(1); + break; + default: + break; + } } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 46ee9bf61df4..1756511b873e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8672,10 +8672,13 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu) } EXPORT_SYMBOL_GPL(kvm_emulate_halt); -int kvm_emulate_ap_reset_hold(struct kvm_vcpu *vcpu) +int kvm_emulate_ap_reset_hold(struct kvm_vcpu *vcpu, + enum ap_reset_hold_type type) { int ret = kvm_skip_emulated_instruction(vcpu); + vcpu->arch.reset_hold_type = type; + return __kvm_vcpu_halt(vcpu, KVM_MP_STATE_AP_RESET_HOLD, KVM_EXIT_AP_RESET_HOLD) && ret; } EXPORT_SYMBOL_GPL(kvm_emulate_ap_reset_hold);