From nobody Sun Sep 7 12:30:00 2025 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 B5B7DCDB474 for ; Mon, 16 Oct 2023 16:31:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234224AbjJPQbs (ORCPT ); Mon, 16 Oct 2023 12:31:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232901AbjJPQbP (ORCPT ); Mon, 16 Oct 2023 12:31:15 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 180265B85; Mon, 16 Oct 2023 09:21:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697473292; x=1729009292; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=lvtKdAbvSruARIIUTgUX05ZaeGu2lt0K7gMh+wYssn8=; b=lF8yVv6E2dZ2I1noezTGvziRZXBqmKxgNDMty++RLUQiz8h2VsNVwIxT pXlHXalX5bqCnkRbb6JGBbyQwxcyWpi3G+MOAtBIkMUIKVOg0o3tvoo8D oxFl3TJXyuciLrh4WhUsOfRS+q1foP8nGpT+ynwKEdzee+dCEb6YOPrh+ L6mjc0DGUKYKJQIR9vSAIDibSf2Vzywi+udeXr9zKtT9zupLVpTx+m4aO KTfbnuCsU6ysE7uZC8tui+pjOIFHmLQTYWzNM5otdS46DDbydAA1CldzB Z3tqoAfumBoBX1ZUTcUEFqjG7b55LTg9VDq7n0v0FGSC+98PeuSedXCLM g==; X-IronPort-AV: E=McAfee;i="6600,9927,10865"; a="364922059" X-IronPort-AV: E=Sophos;i="6.03,229,1694761200"; d="scan'208";a="364922059" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Oct 2023 09:16:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10865"; a="846448316" X-IronPort-AV: E=Sophos;i="6.03,229,1694761200"; d="scan'208";a="846448316" Received: from ls.sc.intel.com (HELO localhost) ([172.25.112.31]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Oct 2023 09:16:05 -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 , David Matlack , Kai Huang , Zhi Wang , chen.bo@intel.com, hang.yuan@intel.com, tina.zhang@intel.com, Sean Christopherson Subject: [PATCH v16 094/116] KVM: TDX: Handle TDX PV MMIO hypercall Date: Mon, 16 Oct 2023 09:14:46 -0700 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 fd6907d5ba9d..24800d1e597d 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1195,6 +1195,118 @@ static int tdx_emulate_io(struct kvm_vcpu *vcpu) return ret; } =20 +static int tdx_complete_mmio(struct kvm_vcpu *vcpu) +{ + unsigned long val =3D 0; + gpa_t gpa; + int size; + + KVM_BUG_ON(vcpu->mmio_needed !=3D 1, vcpu->kvm); + vcpu->mmio_needed =3D 0; + + if (!vcpu->mmio_is_write) { + gpa =3D vcpu->mmio_fragments[0].gpa; + size =3D 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 siz= e, + 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; + + KVM_BUG_ON(vcpu->mmio_needed, vcpu->kvm); + + size =3D tdvmcall_a0_read(vcpu); + write =3D tdvmcall_a1_read(vcpu); + gpa =3D tdvmcall_a2_read(vcpu); + val =3D write ? tdvmcall_a3_read(vcpu) : 0; + + if (size !=3D 1 && size !=3D 2 && size !=3D 4 && size !=3D 8) + goto error; + if (write !=3D 0 && write !=3D 1) + goto error; + + /* Strip the shared bit, allow MMIO with and without it set. */ + gpa =3D gpa & ~gfn_to_gpa(kvm_gfn_shared_mask(vcpu->kvm)); + + if (size > 8u || ((gpa + size - 1) ^ gpa) & PAGE_MASK) + goto error; + + slot =3D 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 =3D tdx_mmio_write(vcpu, gpa, size, val); + else + r =3D 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 =3D 1; + vcpu->mmio_is_write =3D write; + vcpu->arch.complete_userspace_io =3D tdx_complete_mmio; + + vcpu->run->mmio.phys_addr =3D gpa; + vcpu->run->mmio.len =3D size; + vcpu->run->mmio.is_write =3D write; + vcpu->run->exit_reason =3D KVM_EXIT_MMIO; + + if (write) { + memcpy(vcpu->run->mmio.data, &val, size); + } else { + vcpu->mmio_fragments[0].gpa =3D gpa; + vcpu->mmio_fragments[0].len =3D size; + trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, size, gpa, NULL); + } + return 0; + +error: + tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_INVALID_OPERAND); + return 1; +} + static int handle_tdvmcall(struct kvm_vcpu *vcpu) { if (tdvmcall_exit_type(vcpu)) @@ -1207,6 +1319,8 @@ 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 d68e99f4f5ea..6145143c32ee 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -13734,6 +13734,7 @@ EXPORT_SYMBOL_GPL(kvm_sev_es_string_io); =20 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 0ae59d680145..f5768c394efb 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2686,6 +2686,7 @@ struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struc= t kvm_vcpu *vcpu, gfn_t gfn =20 return NULL; } +EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot); =20 bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { @@ -5920,6 +5921,7 @@ int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_b= us bus_idx, gpa_t addr, r =3D __kvm_io_bus_read(vcpu, bus, &range, val); return r < 0 ? r : 0; } +EXPORT_SYMBOL_GPL(kvm_io_bus_read); =20 /* Caller must hold slots_lock. */ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t a= ddr, --=20 2.25.1