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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E89DC43334 for ; Mon, 27 Jun 2022 21:57:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241849AbiF0V5A (ORCPT ); Mon, 27 Jun 2022 17:57:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241557AbiF0Vzq (ORCPT ); Mon, 27 Jun 2022 17:55:46 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8737B10FF4; Mon, 27 Jun 2022 14:55:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656366903; x=1687902903; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=p054z99WJFcZ2x1sIDXFqvmNIW0hCzY7NTNOb43U3Us=; b=dMYIJIR5zNr8ybZh9xTSenwRjexiXmQhE6icQJRqAjz0MCczvY4yXyWr 9lcz2QdFMMpLprsxOjSMv6gkTRih5MziOMqI7/4/WlXcMmIgN42ysZ20E nKBQxBq33/wYZwuQOlum8NVPi0jkOJTy81FQlyDcLt4QksrtQwltdP2nv mMl1W6smaRg28p6p4w3mx5JgrH0P7GVm9uLxitSwws/ziQzm3B84PSCxh +Nzmx6u36pPo5fdMojAB/Jz+lFfBgk4247oNXRPT+J++P8hzo2lz9PuS+ RGcqFPsfs8ntYy13khO02coxWagntSMTtYwrmu/YRurEwV88lmlVDeXrT A==; X-IronPort-AV: E=McAfee;i="6400,9594,10391"; a="279116117" X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="279116117" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 14:54:59 -0700 X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="657863678" Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 14:54:59 -0700 From: isaku.yamahata@intel.com To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Paolo Bonzini , Sean Christopherson Subject: [PATCH v7 074/102] KVM: TDX: Add support for find pending IRQ in a protected local APIC Date: Mon, 27 Jun 2022 14:54:06 -0700 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Sean Christopherson Add flag and hook to KVM's local APIC management to support determining whether or not a TDX guest as a pending IRQ. For TDX vCPUs, the virtual APIC page is owned by the TDX module and cannot be accessed by KVM. As a result, registers that are virtualized by the CPU, e.g. PPR, cannot be read or written by KVM. To deliver interrupts for TDX guests, KVM must send an IRQ to the CPU on the posted interrupt notification vector. And to determine if TDX vCPU has a pending interrupt, KVM must check if there is an outstanding notification. Return "no interrupt" in kvm_apic_has_interrupt() if the guest APIC is protected to short-circuit the various other flows that try to pull an IRQ out of the vAPIC, the only valid operation is querying _if_ an IRQ is pending, KVM can't do anything based on _which_ IRQ is pending. Intentionally omit sanity checks from other flows, e.g. PPR update, so as not to degrade non-TDX guests with unecessary checks. A well-behaved KVM and userspace will never reach those flows for TDX guests, but reaching them is not fatal if something does go awry. Note, this doesn't handle interrupts that have been delivered to the vCPU but not yet recognized by the core, i.e. interrupts that are sitting in vmcs.GUEST_INTR_STATUS. Querying that state requires a SEAMCALL and will be supported in a future patch. Signed-off-by: Sean Christopherson Signed-off-by: Isaku Yamahata --- arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/irq.c | 3 +++ arch/x86/kvm/lapic.c | 3 +++ arch/x86/kvm/lapic.h | 2 ++ arch/x86/kvm/vmx/main.c | 11 +++++++++++ arch/x86/kvm/vmx/tdx.c | 6 ++++++ arch/x86/kvm/vmx/x86_ops.h | 2 ++ 8 files changed, 29 insertions(+) diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 6982d57e4518..ec98b3f734a2 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -112,6 +112,7 @@ KVM_X86_OP_OPTIONAL(pi_update_irte) KVM_X86_OP_OPTIONAL(pi_start_assignment) KVM_X86_OP_OPTIONAL(apicv_post_state_restore) KVM_X86_OP_OPTIONAL_RET0(dy_apicv_has_pending_interrupt) +KVM_X86_OP_OPTIONAL(protected_apic_has_interrupt) KVM_X86_OP_OPTIONAL(set_hv_timer) KVM_X86_OP_OPTIONAL(cancel_hv_timer) KVM_X86_OP(setup_mce) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 1f5be98b7630..6a940700eb9a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1614,6 +1614,7 @@ struct kvm_x86_ops { void (*pi_start_assignment)(struct kvm *kvm); void (*apicv_post_state_restore)(struct kvm_vcpu *vcpu); bool (*dy_apicv_has_pending_interrupt)(struct kvm_vcpu *vcpu); + bool (*protected_apic_has_interrupt)(struct kvm_vcpu *vcpu); int (*set_hv_timer)(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc, bool *expired); diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index f371f1292ca3..56e52eef0269 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -100,6 +100,9 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *v) if (kvm_cpu_has_extint(v)) return 1; + if (lapic_in_kernel(v) && v->arch.apic->guest_apic_protected) + return static_call(kvm_x86_protected_apic_has_interrupt)(v); + return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ } EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt); diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index a413a1d8df4c..c85ed9f6a8c9 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2585,6 +2585,9 @@ int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu) if (!kvm_apic_present(vcpu)) return -1; + if (apic->guest_apic_protected) + return -1; + __apic_update_ppr(apic, &ppr); return apic_has_interrupt_for_ppr(apic, ppr); } diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index 65bb2a8cf145..1fa316b81fef 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -51,6 +51,8 @@ struct kvm_lapic { bool sw_enabled; bool irr_pending; bool lvt0_in_nmi_mode; + /* Select registers in the vAPIC cannot be read/written. */ + bool guest_apic_protected; /* Number of bits set in ISR. */ s16 isr_count; /* The highest vector set in ISR; if -1 - invalid, must scan ISR. */ diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c index ad09988c4faa..f14519c6a861 100644 --- a/arch/x86/kvm/vmx/main.c +++ b/arch/x86/kvm/vmx/main.c @@ -46,6 +46,9 @@ static __init int vt_hardware_setup(void) enable_tdx = enable_tdx && !tdx_hardware_setup(&vt_x86_ops); + if (!enable_tdx) + vt_x86_ops.protected_apic_has_interrupt = NULL; + if (enable_ept) kvm_mmu_set_ept_masks(enable_ept_ad_bits, cpu_has_vmx_ept_execute_only()); @@ -178,6 +181,13 @@ static void vt_vcpu_load(struct kvm_vcpu *vcpu, int cpu) return vmx_vcpu_load(vcpu, cpu); } +static bool vt_protected_apic_has_interrupt(struct kvm_vcpu *vcpu) +{ + KVM_BUG_ON(!is_td_vcpu(vcpu), vcpu->kvm); + + return tdx_protected_apic_has_interrupt(vcpu); +} + static void vt_flush_tlb_all(struct kvm_vcpu *vcpu) { if (is_td_vcpu(vcpu)) @@ -329,6 +339,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = { .sync_pir_to_irr = vmx_sync_pir_to_irr, .deliver_interrupt = vmx_deliver_interrupt, .dy_apicv_has_pending_interrupt = pi_has_pending_interrupt, + .protected_apic_has_interrupt = vt_protected_apic_has_interrupt, .set_tss_addr = vmx_set_tss_addr, .set_identity_map_addr = vmx_set_identity_map_addr, diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index c256853efed5..244477713fee 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -526,6 +526,7 @@ int tdx_vcpu_create(struct kvm_vcpu *vcpu) return -EINVAL; fpstate_set_confidential(&vcpu->arch.guest_fpu); + vcpu->arch.apic->guest_apic_protected = true; ret = tdx_alloc_td_page(&tdx->tdvpr); if (ret) @@ -590,6 +591,11 @@ void tdx_vcpu_load(struct kvm_vcpu *vcpu, int cpu) local_irq_enable(); } +bool tdx_protected_apic_has_interrupt(struct kvm_vcpu *vcpu) +{ + return pi_has_pending_interrupt(vcpu); +} + void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) { struct vcpu_tdx *tdx = to_tdx(vcpu); diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h index 55273a0fe273..17aaa0b3d921 100644 --- a/arch/x86/kvm/vmx/x86_ops.h +++ b/arch/x86/kvm/vmx/x86_ops.h @@ -147,6 +147,7 @@ fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu); void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu); void tdx_vcpu_put(struct kvm_vcpu *vcpu); void tdx_vcpu_load(struct kvm_vcpu *vcpu, int cpu); +bool tdx_protected_apic_has_interrupt(struct kvm_vcpu *vcpu); int tdx_vm_ioctl(struct kvm *kvm, void __user *argp); int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp); @@ -173,6 +174,7 @@ static inline fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu) { return EXIT_FASTP static inline void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) {} static inline void tdx_vcpu_put(struct kvm_vcpu *vcpu) {} static inline void tdx_vcpu_load(struct kvm_vcpu *vcpu, int cpu) {} +static inline bool tdx_protected_apic_has_interrupt(struct kvm_vcpu *vcpu) { return false; } static inline int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { return -EOPNOTSUPP; } static inline int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) { return -EOPNOTSUPP; } -- 2.25.1