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=-14.5 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FUZZY_XPILL,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 08897C433E0 for ; Tue, 19 May 2020 22:22:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD1C92072C for ; Tue, 19 May 2020 22:22:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="mwUbPEj0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725998AbgESWWz (ORCPT ); Tue, 19 May 2020 18:22:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726432AbgESWWz (ORCPT ); Tue, 19 May 2020 18:22:55 -0400 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 332CFC061A0F for ; Tue, 19 May 2020 15:22:54 -0700 (PDT) Received: by mail-qt1-x849.google.com with SMTP id z29so1434935qtj.5 for ; Tue, 19 May 2020 15:22:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=bCJWmHbze1pLLih718jeliFNM3BKqGb8v3takoCjUgM=; b=mwUbPEj0O8gsWGPPjwy7WK6wbWiPEhZ/9djjleiE9hbD+JPX0QGsTKsEZYLLpnkGEB AxPnpEMRpH8DH0gvXv56X5nOU4a1ix0jJQSz2X7YaEs5vM8cjza1YgUAGhl+2RGCRC/8 P11rFvKwtfjGL7j5e+mb5Z82hMepwcwhK6ua83ItPxy1GqkSLb3HPzY5EL5xQjl4uviG DOU3dyEbG2dbBCL4CXIcBzhSMhp1mK+4v91yhKSCSI8i9i3hyIuU8Psng52943m8ZiZE 8dZZWbJn71Mjah4mf13ifBUaOa9xmoY4qNZCJGwsKKotu5BYiXqqNiUg1unqvOsRMjzU s4hg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=bCJWmHbze1pLLih718jeliFNM3BKqGb8v3takoCjUgM=; b=cgFu+8c7YOOfBZKnEIVNbH+JHmz1cwT/ZanaO9OFNxgjteHeC9Ygk7XurtiuKxcFD9 Rc1qU/ePKu0Cz+Y5AgF0Yw6FrU+cUMWhw3FPxNN+17ynKZ+dG2XuQwz3PBXpYBC543fP 9kqimtumW7R8lP02QkT1SsWtZlyXHozgmOcFU4pZHmaUHIymN5bWTOwMzocMZq1avkGe AelXLVf4ecwhSd3DSjqwB+jU0cTdCo1S36vSTiGP/SznVyb9ZXC80gRvr5nf4pt1NpUu n4ptGjPGF62YjGhUAqKEIKwsABcLW9CPQsLNKGjYPPETnLXuTfQjDAMUOJiavGEpy18k M/PQ== X-Gm-Message-State: AOAM530/tuYl8GfvB4cI3OnZfayH7Wl+1Ui3jZZnBXkB76w1Z7lknXND ZQek84Y69wGHrki2xlNTzaOidfZzoiUDRoErFmESKjex+8YjWk06Wk7W5wc8aCEtgR0j9IdmTBx sLp/QGxlz4TkKC606j1/MCzRY2y4KvE6Z8kQgXXe20VPLYpCVoyJoJXhbCJJMmw807016LsTO8n qgc6A= X-Google-Smtp-Source: ABdhPJwAWec4iG4MOqtZLYCA8D2mJSqbmHHmeAiZuuGdc/at+/qqP8n3ZIXg7wkCHQwDNrmRiqpB4tBMkDBt36buWC/hug== X-Received: by 2002:a05:6214:1427:: with SMTP id o7mr2015675qvx.104.1589926973326; Tue, 19 May 2020 15:22:53 -0700 (PDT) Date: Tue, 19 May 2020 15:22:37 -0700 In-Reply-To: <20200519222238.213574-1-makarandsonare@google.com> Message-Id: <20200519222238.213574-2-makarandsonare@google.com> Mime-Version: 1.0 References: <20200519222238.213574-1-makarandsonare@google.com> X-Mailer: git-send-email 2.26.2.761.g0e0b3e54be-goog Subject: [PATCH v2 1/2] KVM: nVMX: Fix VMX preemption timer migration From: Makarand Sonare To: kvm@vger.kernel.org, pshier@google.com, jmattson@google.com Cc: Makarand Sonare Content-Type: text/plain; charset="UTF-8" Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Peter Shier Add new field to hold preemption timer expiration deadline appended to struct kvm_vmx_nested_state_data. This is to prevent the first VM-Enter after migration from incorrectly restarting the timer with the full timer value instead of partially decayed timer value. KVM_SET_NESTED_STATE restarts timer using migrated state regardless of whether L1 sets VM_EXIT_SAVE_VMX_PREEMPTION_TIMER. Fixes: cf8b84f48a593 ("kvm: nVMX: Prepare for checkpointing L2 state") Signed-off-by: Peter Shier Signed-off-by: Makarand Sonare Change-Id: I6446aba5a547afa667f0ef4620b1b76115bf3753 --- Documentation/virt/kvm/api.rst | 4 +++ arch/x86/include/uapi/asm/kvm.h | 3 ++ arch/x86/kvm/vmx/nested.c | 56 +++++++++++++++++++++++++++++---- arch/x86/kvm/vmx/vmx.h | 1 + arch/x86/kvm/x86.c | 3 +- include/uapi/linux/kvm.h | 1 + 6 files changed, 61 insertions(+), 7 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index d871dacb984e9..b410815772970 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -4326,6 +4326,9 @@ Errors: #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 #define KVM_STATE_NESTED_EVMCS 0x00000004 + /* Available with KVM_CAP_NESTED_STATE_PREEMPTION_TIMER */ + #define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 + #define KVM_STATE_NESTED_FORMAT_VMX 0 #define KVM_STATE_NESTED_FORMAT_SVM 1 @@ -4346,6 +4349,7 @@ Errors: struct kvm_vmx_nested_state_data { __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; + __u64 preemption_timer_deadline; }; This ioctl copies the vcpu's nested virtualization state from the kernel to diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index 3f3f780c8c650..13dca545554dc 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -391,6 +391,8 @@ struct kvm_sync_regs { #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 #define KVM_STATE_NESTED_EVMCS 0x00000004 #define KVM_STATE_NESTED_MTF_PENDING 0x00000008 +/* Available with KVM_CAP_NESTED_STATE_PREEMPTION_TIMER */ +#define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 #define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001 #define KVM_STATE_NESTED_SMM_VMXON 0x00000002 @@ -400,6 +402,7 @@ struct kvm_sync_regs { struct kvm_vmx_nested_state_data { __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; + __u64 preemption_timer_deadline; }; struct kvm_vmx_nested_state_hdr { diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 51ebb60e1533a..318b753743902 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2092,9 +2092,9 @@ static enum hrtimer_restart vmx_preemption_timer_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } -static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu) +static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu, + u64 preemption_timeout) { - u64 preemption_timeout = get_vmcs12(vcpu)->vmx_preemption_timer_value; struct vcpu_vmx *vmx = to_vmx(vcpu); /* @@ -3353,8 +3353,20 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, * the timer. */ vmx->nested.preemption_timer_expired = false; - if (nested_cpu_has_preemption_timer(vmcs12)) - vmx_start_preemption_timer(vcpu); + if (nested_cpu_has_preemption_timer(vmcs12)) { + u64 timer_value = 0; + u64 l1_scaled_tsc_value = (kvm_read_l1_tsc(vcpu, rdtsc()) + >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE); + + if (from_vmentry) { + timer_value = vmcs12->vmx_preemption_timer_value; + vmx->nested.preemption_timer_deadline = timer_value + + l1_scaled_tsc_value; + } else if (l1_scaled_tsc_value <= vmx->nested.preemption_timer_deadline) + timer_value = vmx->nested.preemption_timer_deadline - + l1_scaled_tsc_value; + vmx_start_preemption_timer(vcpu, timer_value); + } /* * Note no nested_vmx_succeed or nested_vmx_fail here. At this point @@ -3962,9 +3974,11 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) vmcs12->guest_activity_state = GUEST_ACTIVITY_ACTIVE; if (nested_cpu_has_preemption_timer(vmcs12) && - vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER) + !vmx->nested.nested_run_pending) { + if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER) vmcs12->vmx_preemption_timer_value = vmx_get_preemption_timer_value(vcpu); + } /* * In some cases (usually, nested EPT), L2 is allowed to change its @@ -5939,6 +5953,12 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, if (vmx->nested.mtf_pending) kvm_state.flags |= KVM_STATE_NESTED_MTF_PENDING; + + if (nested_cpu_has_preemption_timer(vmcs12)) { + kvm_state.flags |= + KVM_STATE_NESTED_PREEMPTION_TIMER; + kvm_state.size += sizeof(user_vmx_nested_state->preemption_timer_deadline); + } } } @@ -5970,6 +5990,9 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, BUILD_BUG_ON(sizeof(user_vmx_nested_state->vmcs12) < VMCS12_SIZE); BUILD_BUG_ON(sizeof(user_vmx_nested_state->shadow_vmcs12) < VMCS12_SIZE); + BUILD_BUG_ON(sizeof(user_vmx_nested_state->preemption_timer_deadline) + != sizeof(vmx->nested.preemption_timer_deadline)); + /* * Copy over the full allocated size of vmcs12 rather than just the size @@ -5985,6 +6008,12 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, return -EFAULT; } + if (kvm_state.flags & KVM_STATE_NESTED_PREEMPTION_TIMER) { + if (put_user(vmx->nested.preemption_timer_deadline, + &user_vmx_nested_state->preemption_timer_deadline)) + return -EFAULT; + } + out: return kvm_state.size; } @@ -6056,7 +6085,8 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, */ if (is_smm(vcpu) ? (kvm_state->flags & - (KVM_STATE_NESTED_GUEST_MODE | KVM_STATE_NESTED_RUN_PENDING)) + (KVM_STATE_NESTED_GUEST_MODE | KVM_STATE_NESTED_RUN_PENDING | + KVM_STATE_NESTED_PREEMPTION_TIMER)) : kvm_state->hdr.vmx.smm.flags) return -EINVAL; @@ -6146,6 +6176,20 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, goto error_guest_mode; } + if (kvm_state->flags & KVM_STATE_NESTED_PREEMPTION_TIMER) { + + if (kvm_state->size < + sizeof(*kvm_state) + + sizeof(user_vmx_nested_state->vmcs12) + sizeof(vmx->nested.preemption_timer_deadline)) + goto error_guest_mode; + + if (get_user(vmx->nested.preemption_timer_deadline, + &user_vmx_nested_state->preemption_timer_deadline)) { + ret = -EFAULT; + goto error_guest_mode; + } + } + if (nested_vmx_check_controls(vcpu, vmcs12) || nested_vmx_check_host_state(vcpu, vmcs12) || nested_vmx_check_guest_state(vcpu, vmcs12, &ignored)) diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 298ddef79d009..db697400755fb 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -169,6 +169,7 @@ struct nested_vmx { u16 posted_intr_nv; struct hrtimer preemption_timer; + u64 preemption_timer_deadline; bool preemption_timer_expired; /* to migrate it to L2 if VM_ENTRY_LOAD_DEBUG_CONTROLS is off */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 471fccf7f8501..ba9e62ffbb4cd 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3418,6 +3418,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_MSR_PLATFORM_INFO: case KVM_CAP_EXCEPTION_PAYLOAD: case KVM_CAP_SET_GUEST_DEBUG: + case KVM_CAP_NESTED_STATE_PREEMPTION_TIMER: r = 1; break; case KVM_CAP_SYNC_REGS: @@ -4626,7 +4627,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, if (kvm_state.flags & ~(KVM_STATE_NESTED_RUN_PENDING | KVM_STATE_NESTED_GUEST_MODE - | KVM_STATE_NESTED_EVMCS)) + | KVM_STATE_NESTED_EVMCS | KVM_STATE_NESTED_PREEMPTION_TIMER)) break; /* nested_run_pending implies guest_mode. */ diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index ac9eba0289d1b..0868dce12a715 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1018,6 +1018,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_S390_PROTECTED 180 #define KVM_CAP_PPC_SECURE_GUEST 181 #define KVM_CAP_HALT_POLL 182 +#define KVM_CAP_NESTED_STATE_PREEMPTION_TIMER 183 #ifdef KVM_CAP_IRQ_ROUTING -- 2.26.2.761.g0e0b3e54be-goog