From patchwork Wed May 26 18:44:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilias Stamatis X-Patchwork-Id: 12282581 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 85771C47082 for ; Wed, 26 May 2021 18:47:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60C5B613C3 for ; Wed, 26 May 2021 18:47:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235716AbhEZSs4 (ORCPT ); Wed, 26 May 2021 14:48:56 -0400 Received: from smtp-fw-2101.amazon.com ([72.21.196.25]:27682 "EHLO smtp-fw-2101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235712AbhEZSsy (ORCPT ); Wed, 26 May 2021 14:48:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1622054844; x=1653590844; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=OoyYtF6x3IG1coV85+nkBAzyCgT+6pLRLqQkBqOr044=; b=GaGCpHUN34YvjdoL9Vr2eJoB3CwMKzmAdXz7TXZalKKP0xZ8dd8lCIDI SQHmcgEgoGaPXMqDxwYfh4wrSQc0uSH4LuMb9MjGvdQEZPboxrJ1lfhDW UWfps88iYsLZqSSiMF/PuJpOJlRzJqm9HrH7VrBQpPm+k3rpJARw0MVGt I=; X-IronPort-AV: E=Sophos;i="5.82,331,1613433600"; d="scan'208";a="111927114" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-1d-2c665b5d.us-east-1.amazon.com) ([10.43.8.2]) by smtp-border-fw-2101.iad2.amazon.com with ESMTP; 26 May 2021 18:47:23 +0000 Received: from EX13MTAUEE001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-2c665b5d.us-east-1.amazon.com (Postfix) with ESMTPS id E5959A1A7B; Wed, 26 May 2021 18:47:18 +0000 (UTC) Received: from EX13D08UEE004.ant.amazon.com (10.43.62.182) by EX13MTAUEE001.ant.amazon.com (10.43.62.200) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Wed, 26 May 2021 18:46:59 +0000 Received: from EX13MTAUEA001.ant.amazon.com (10.43.61.82) by EX13D08UEE004.ant.amazon.com (10.43.62.182) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Wed, 26 May 2021 18:46:59 +0000 Received: from uae075a0dfd4c51.ant.amazon.com (10.106.82.24) by mail-relay.amazon.com (10.43.61.243) with Microsoft SMTP Server id 15.0.1497.18 via Frontend Transport; Wed, 26 May 2021 18:46:57 +0000 From: Ilias Stamatis To: , , CC: , , , , , , , , , Subject: [PATCH v4 09/11] KVM: X86: Add vendor callbacks for writing the TSC multiplier Date: Wed, 26 May 2021 19:44:16 +0100 Message-ID: <20210526184418.28881-10-ilstam@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210526184418.28881-1-ilstam@amazon.com> References: <20210526184418.28881-1-ilstam@amazon.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Currently vmx_vcpu_load_vmcs() writes the TSC_MULTIPLIER field of the VMCS every time the VMCS is loaded. Instead of doing this, set this field from common code on initialization and whenever the scaling ratio changes. Additionally remove vmx->current_tsc_ratio. This field is redundant as vcpu->arch.tsc_scaling_ratio already tracks the current TSC scaling ratio. The vmx->current_tsc_ratio field is only used for avoiding unnecessary writes but it is no longer needed after removing the code from the VMCS load path. Suggested-by: Sean Christopherson Signed-off-by: Ilias Stamatis --- arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm/svm.c | 6 ++++++ arch/x86/kvm/vmx/nested.c | 9 ++++----- arch/x86/kvm/vmx/vmx.c | 11 ++++++----- arch/x86/kvm/vmx/vmx.h | 8 -------- arch/x86/kvm/x86.c | 28 +++++++++++++++++++++++----- 7 files changed, 41 insertions(+), 23 deletions(-) diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 029c9615378f..34ad7a17458a 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -90,6 +90,7 @@ KVM_X86_OP_NULL(has_wbinvd_exit) KVM_X86_OP(get_l2_tsc_offset) KVM_X86_OP(get_l2_tsc_multiplier) KVM_X86_OP(write_tsc_offset) +KVM_X86_OP(write_tsc_multiplier) KVM_X86_OP(get_exit_info) KVM_X86_OP(check_intercept) KVM_X86_OP(handle_exit_irqoff) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f099277b993d..a334ce7741ab 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1308,6 +1308,7 @@ struct kvm_x86_ops { u64 (*get_l2_tsc_offset)(struct kvm_vcpu *vcpu); u64 (*get_l2_tsc_multiplier)(struct kvm_vcpu *vcpu); void (*write_tsc_offset)(struct kvm_vcpu *vcpu, u64 offset); + void (*write_tsc_multiplier)(struct kvm_vcpu *vcpu, u64 multiplier); /* * Retrieve somewhat arbitrary exit information. Intended to be used diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 8dfb2513b72a..cb701b42b08b 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1103,6 +1103,11 @@ static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS); } +static void svm_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 multiplier) +{ + wrmsrl(MSR_AMD64_TSC_RATIO, multiplier); +} + /* Evaluate instruction intercepts that depend on guest CPUID features. */ static void svm_recalc_instruction_intercepts(struct kvm_vcpu *vcpu, struct vcpu_svm *svm) @@ -4528,6 +4533,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .get_l2_tsc_offset = svm_get_l2_tsc_offset, .get_l2_tsc_multiplier = svm_get_l2_tsc_multiplier, .write_tsc_offset = svm_write_tsc_offset, + .write_tsc_multiplier = svm_write_tsc_multiplier, .load_mmu_pgd = svm_load_mmu_pgd, diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 6058a65a6ede..239154d3e4e7 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2533,9 +2533,8 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, } vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset); - if (kvm_has_tsc_control) - decache_tsc_multiplier(vmx); + vmcs_write64(TSC_MULTIPLIER, vcpu->arch.tsc_scaling_ratio); nested_vmx_transition_tlb_flush(vcpu, vmcs12, true); @@ -4501,12 +4500,12 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason, vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr); vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr); vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset); + if (kvm_has_tsc_control) + vmcs_write64(TSC_MULTIPLIER, vcpu->arch.tsc_scaling_ratio); + if (vmx->nested.l1_tpr_threshold != -1) vmcs_write32(TPR_THRESHOLD, vmx->nested.l1_tpr_threshold); - if (kvm_has_tsc_control) - decache_tsc_multiplier(vmx); - if (vmx->nested.change_vmcs01_virtual_apic_mode) { vmx->nested.change_vmcs01_virtual_apic_mode = false; vmx_set_virtual_apic_mode(vcpu); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 4b70431c2edd..bf845a08995e 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1390,11 +1390,6 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu, vmx->loaded_vmcs->cpu = cpu; } - - /* Setup TSC multiplier */ - if (kvm_has_tsc_control && - vmx->current_tsc_ratio != vcpu->arch.tsc_scaling_ratio) - decache_tsc_multiplier(vmx); } /* @@ -1813,6 +1808,11 @@ static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) vmcs_write64(TSC_OFFSET, offset); } +static void vmx_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 multiplier) +{ + vmcs_write64(TSC_MULTIPLIER, multiplier); +} + /* * nested_vmx_allowed() checks whether a guest should be allowed to use VMX * instructions and MSRs (i.e., nested VMX). Nested VMX is disabled for @@ -7707,6 +7707,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = { .get_l2_tsc_offset = vmx_get_l2_tsc_offset, .get_l2_tsc_multiplier = vmx_get_l2_tsc_multiplier, .write_tsc_offset = vmx_write_tsc_offset, + .write_tsc_multiplier = vmx_write_tsc_multiplier, .load_mmu_pgd = vmx_load_mmu_pgd, diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index aa97c82e3451..3eaa86a0ba3e 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -322,8 +322,6 @@ struct vcpu_vmx { /* apic deadline value in host tsc */ u64 hv_deadline_tsc; - u64 current_tsc_ratio; - unsigned long host_debugctlmsr; /* @@ -532,12 +530,6 @@ static inline struct vmcs *alloc_vmcs(bool shadow) GFP_KERNEL_ACCOUNT); } -static inline void decache_tsc_multiplier(struct vcpu_vmx *vmx) -{ - vmx->current_tsc_ratio = vmx->vcpu.arch.tsc_scaling_ratio; - vmcs_write64(TSC_MULTIPLIER, vmx->current_tsc_ratio); -} - static inline bool vmx_has_waitpkg(struct vcpu_vmx *vmx) { return vmx->secondary_exec_control & diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 801fa1e8e915..8afe2c29183c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2179,14 +2179,15 @@ static u32 adjust_tsc_khz(u32 khz, s32 ppm) return v; } +static void kvm_vcpu_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 l1_multiplier); + static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale) { u64 ratio; /* Guest TSC same frequency as host TSC? */ if (!scale) { - vcpu->arch.l1_tsc_scaling_ratio = kvm_default_tsc_scaling_ratio; - vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio; + kvm_vcpu_write_tsc_multiplier(vcpu, kvm_default_tsc_scaling_ratio); return 0; } @@ -2212,7 +2213,7 @@ static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale) return -1; } - vcpu->arch.l1_tsc_scaling_ratio = vcpu->arch.tsc_scaling_ratio = ratio; + kvm_vcpu_write_tsc_multiplier(vcpu, ratio); return 0; } @@ -2224,8 +2225,7 @@ static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz) /* tsc_khz can be zero if TSC calibration fails */ if (user_tsc_khz == 0) { /* set tsc_scaling_ratio to a safe value */ - vcpu->arch.l1_tsc_scaling_ratio = kvm_default_tsc_scaling_ratio; - vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio; + kvm_vcpu_write_tsc_multiplier(vcpu, kvm_default_tsc_scaling_ratio); return -1; } @@ -2383,6 +2383,23 @@ static void kvm_vcpu_write_tsc_offset(struct kvm_vcpu *vcpu, u64 l1_offset) static_call(kvm_x86_write_tsc_offset)(vcpu, vcpu->arch.tsc_offset); } +static void kvm_vcpu_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 l1_multiplier) +{ + vcpu->arch.l1_tsc_scaling_ratio = l1_multiplier; + + /* Userspace is changing the multiplier while L2 is active */ + if (is_guest_mode(vcpu)) + vcpu->arch.tsc_scaling_ratio = kvm_calc_nested_tsc_multiplier( + l1_multiplier, + static_call(kvm_x86_get_l2_tsc_multiplier)(vcpu)); + else + vcpu->arch.tsc_scaling_ratio = l1_multiplier; + + if (kvm_has_tsc_control) + static_call(kvm_x86_write_tsc_multiplier)( + vcpu, vcpu->arch.tsc_scaling_ratio); +} + static inline bool kvm_check_tsc_unstable(void) { #ifdef CONFIG_X86_64 @@ -10444,6 +10461,7 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) return; vcpu_load(vcpu); kvm_synchronize_tsc(vcpu, 0); + kvm_vcpu_write_tsc_multiplier(vcpu, kvm_default_tsc_scaling_ratio); vcpu_put(vcpu); /* poll control enabled by default */