From patchwork Thu May 5 18:15:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Isaku Yamahata X-Patchwork-Id: 12839901 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 E5591C433EF for ; Thu, 5 May 2022 18:17:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383400AbiEESVG (ORCPT ); Thu, 5 May 2022 14:21:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1383255AbiEESTn (ORCPT ); Thu, 5 May 2022 14:19:43 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B045A5DA5F; Thu, 5 May 2022 11:15:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1651774556; x=1683310556; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=us0aw+tDgkcNliX/K/zSuPp2+zwEh9mJDQ0zdicKY1g=; b=BOM/q6Hwj7zaxpKaDG6S+g2H9/KVJ8ttBF6EbhERFxPvpzuE2CMYgUpR 7afp1uK7Z3jNh/8FDyeMrlKiYcPT5Gi7QEEwDul5CykV1q4ItRKfOCZut ybYizePXXX/NbalrKdMKBCWtD+8kzZgdzH2JXtq80GzG5TFwnCkKb3HRZ NlGF25C7TmxD5JyR28N+s9NE1MvTQZpNoj8AVTgl+97bwvxuffxV5z2ZF iSsdFz2/7OaS7PDUyzNrPAYnga1Qx4bTovtuSfxcBO3g6+hJNwRljbm// +lxHcnwpHLGE+p98iPlRT+JnrIi77MZtx8fuvUs4Mi14suDdEjMPz3QsH Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10338"; a="268097116" X-IronPort-AV: E=Sophos;i="5.91,202,1647327600"; d="scan'208";a="268097116" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2022 11:15:55 -0700 X-IronPort-AV: E=Sophos;i="5.91,202,1647327600"; d="scan'208";a="665083479" Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2022 11:15:54 -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 , erdemaktas@google.com, Sean Christopherson , Sagi Shahar Subject: [RFC PATCH v6 093/104] KVM: TDX: Handle TDX PV MMIO hypercall Date: Thu, 5 May 2022 11:15:27 -0700 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Sean Christopherson Export kvm_io_bus_read and kvm_mmio tracepoint and wire up TDX PV MMIO hypercall to the KVM backend functions. kvm_io_bus_read/write() searches KVM device emulated in kernel of the given MMIO address and emulates the MMIO. As TDX PV MMIO also needs it, export kvm_io_bus_read(). kvm_io_bus_write() is already exported. TDX PV MMIO emulates some of MMIO itself. To add trace point consistently with x86 kvm, export kvm_mmio tracepoint. Signed-off-by: Sean Christopherson Signed-off-by: Isaku Yamahata Reviewed-by: Paolo Bonzini --- arch/x86/kvm/vmx/tdx.c | 114 +++++++++++++++++++++++++++++++++++++++++ arch/x86/kvm/x86.c | 1 + virt/kvm/kvm_main.c | 2 + 3 files changed, 117 insertions(+) diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index ee0cf5336ade..6ab4a52fc9e9 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1057,6 +1057,118 @@ static int tdx_emulate_io(struct kvm_vcpu *vcpu) return ret; } +static int tdx_complete_mmio(struct kvm_vcpu *vcpu) +{ + unsigned long val = 0; + gpa_t gpa; + int size; + + WARN_ON(vcpu->mmio_needed != 1); + vcpu->mmio_needed = 0; + + if (!vcpu->mmio_is_write) { + gpa = vcpu->mmio_fragments[0].gpa; + size = vcpu->mmio_fragments[0].len; + + memcpy(&val, vcpu->run->mmio.data, size); + tdvmcall_set_return_val(vcpu, val); + trace_kvm_mmio(KVM_TRACE_MMIO_READ, size, gpa, &val); + } + return 1; +} + +static inline int tdx_mmio_write(struct kvm_vcpu *vcpu, gpa_t gpa, int size, + unsigned long val) +{ + if (kvm_iodevice_write(vcpu, &vcpu->arch.apic->dev, gpa, size, &val) && + kvm_io_bus_write(vcpu, KVM_MMIO_BUS, gpa, size, &val)) + return -EOPNOTSUPP; + + trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, size, gpa, &val); + return 0; +} + +static inline int tdx_mmio_read(struct kvm_vcpu *vcpu, gpa_t gpa, int size) +{ + unsigned long val; + + if (kvm_iodevice_read(vcpu, &vcpu->arch.apic->dev, gpa, size, &val) && + kvm_io_bus_read(vcpu, KVM_MMIO_BUS, gpa, size, &val)) + return -EOPNOTSUPP; + + tdvmcall_set_return_val(vcpu, val); + trace_kvm_mmio(KVM_TRACE_MMIO_READ, size, gpa, &val); + return 0; +} + +static int tdx_emulate_mmio(struct kvm_vcpu *vcpu) +{ + struct kvm_memory_slot *slot; + int size, write, r; + unsigned long val; + gpa_t gpa; + + WARN_ON(vcpu->mmio_needed); + + size = tdvmcall_a0_read(vcpu); + write = tdvmcall_a1_read(vcpu); + gpa = tdvmcall_a2_read(vcpu); + val = write ? tdvmcall_a3_read(vcpu) : 0; + + if (size != 1 && size != 2 && size != 4 && size != 8) + goto error; + if (write != 0 && write != 1) + goto error; + + /* Strip the shared bit, allow MMIO with and without it set. */ + gpa = gpa & ~gfn_to_gpa(kvm_gfn_shared_mask(vcpu->kvm)); + + if (size > 8u || ((gpa + size - 1) ^ gpa) & PAGE_MASK) + goto error; + + slot = kvm_vcpu_gfn_to_memslot(vcpu, gpa_to_gfn(gpa)); + if (slot && !(slot->flags & KVM_MEMSLOT_INVALID)) + goto error; + + if (!kvm_io_bus_write(vcpu, KVM_FAST_MMIO_BUS, gpa, 0, NULL)) { + trace_kvm_fast_mmio(gpa); + return 1; + } + + if (write) + r = tdx_mmio_write(vcpu, gpa, size, val); + else + r = tdx_mmio_read(vcpu, gpa, size); + if (!r) { + /* Kernel completed device emulation. */ + tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_SUCCESS); + return 1; + } + + /* Request the device emulation to userspace device model. */ + vcpu->mmio_needed = 1; + vcpu->mmio_is_write = write; + vcpu->arch.complete_userspace_io = tdx_complete_mmio; + + vcpu->run->mmio.phys_addr = gpa; + vcpu->run->mmio.len = size; + vcpu->run->mmio.is_write = write; + vcpu->run->exit_reason = KVM_EXIT_MMIO; + + if (write) { + memcpy(vcpu->run->mmio.data, &val, size); + } else { + vcpu->mmio_fragments[0].gpa = gpa; + vcpu->mmio_fragments[0].len = size; + trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, size, gpa, NULL); + } + return 0; + +error: + tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_SUCCESS); + return 1; +} + static int handle_tdvmcall(struct kvm_vcpu *vcpu) { if (tdvmcall_exit_type(vcpu)) @@ -1069,6 +1181,8 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu) return tdx_emulate_hlt(vcpu); case EXIT_REASON_IO_INSTRUCTION: return tdx_emulate_io(vcpu); + case EXIT_REASON_EPT_VIOLATION: + return tdx_emulate_mmio(vcpu); default: break; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5f291470a6f6..f367d0dcef97 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -13166,6 +13166,7 @@ bool kvm_arch_dirty_log_supported(struct kvm *kvm) EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_entry); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit); +EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_mmio); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 4bf7178e42bd..7f01131666de 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2294,6 +2294,7 @@ struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn return NULL; } +EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot); bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { @@ -5169,6 +5170,7 @@ int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr, r = __kvm_io_bus_read(vcpu, bus, &range, val); return r < 0 ? r : 0; } +EXPORT_SYMBOL_GPL(kvm_io_bus_read); /* Caller must hold slots_lock. */ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,