From nobody Fri Sep 5 06:18:02 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 18D6FCDB465 for ; Mon, 16 Oct 2023 16:36:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234405AbjJPQgN (ORCPT ); Mon, 16 Oct 2023 12:36:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234338AbjJPQfl (ORCPT ); Mon, 16 Oct 2023 12:35:41 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7175847B3; Mon, 16 Oct 2023 09:20:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697473241; x=1729009241; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=vMtq6/XiGTFGPWnTNNii6J7CNM56w+LDhgFUdcvWZnI=; b=StYql6blczbAMCczI+WyDdN1PcmJeF129dw7FNTYNYpEGRuDwXtWZ1g+ 4kFcjkRy7oJV4x+UDsI38WQqGNK8WMWFoL+1Dz+iLo5hNTF8C3XcG0Qdy CnqcoZBYf4a+ecZ7q1aQpJI9AA3aSwkoxl/sA+aIPk4rar+gLCoRGmoIO KvUNWpGAjp/D60rcjsR0Rp2ZTeVKMU1t/6duD4EbOXIJ/BTkUrPZISAdy 7/akHdEBdEJdzpJghzJoNlhbm/kAJS3Cu4n5DEAHvkN40c0pEYmopvl3Y QNVlFIZygUNMJemFsdKCNGUSJeAGEesmFcTNMJBl/gFl35qcKdeodkk/Z w==; X-IronPort-AV: E=McAfee;i="6600,9927,10865"; a="364922029" X-IronPort-AV: E=Sophos;i="6.03,229,1694761200"; d="scan'208";a="364922029" 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 09:16:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10865"; a="846448294" X-IronPort-AV: E=Sophos;i="6.03,229,1694761200"; d="scan'208";a="846448294" 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 09:16:03 -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 Subject: [PATCH v16 090/116] KVM: TDX: Add KVM Exit for TDX TDG.VP.VMCALL Date: Mon, 16 Oct 2023 09:14:42 -0700 Message-Id: <811dbc6f7345c43219daf8d682fe092b734fe416.1697471314.git.isaku.yamahata@intel.com> 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: Isaku Yamahata Some of TDG.VP.VMCALL require device model, for example, qemu, to handle them on behalf of kvm kernel module. TDG_VP_VMCALL_REPORT_FATAL_ERROR, TDG_VP_VMCALL_MAP_GPA, TDG_VP_VMCALL_SETUP_EVENT_NOTIFY_INTERRUPT, and TDG_VP_VMCALL_GET_QUOTE requires user space VMM handling. Introduce new kvm exit, KVM_EXIT_TDX, and functions to setup it. TDG_VP_VMCALL_INVALID_OPERAND is set as default return value to avoid random value. Device model should update R10 if necessary. Signed-off-by: Isaku Yamahata --- v14 -> v15: - updated struct kvm_tdx_exit with union - export constants for reg bitmask --- arch/x86/kvm/vmx/tdx.c | 84 +++++++++++++++++++++++++++++++++++++- include/uapi/linux/kvm.h | 87 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 169 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 89e92c696760..eb6ba2eee16c 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1012,6 +1012,78 @@ static int tdx_emulate_vmcall(struct kvm_vcpu *vcpu) return 1; } =20 +static int tdx_complete_vp_vmcall(struct kvm_vcpu *vcpu) +{ + struct kvm_tdx_vmcall *tdx_vmcall =3D &vcpu->run->tdx.u.vmcall; + __u64 reg_mask =3D kvm_rcx_read(vcpu); + +#define COPY_REG(MASK, REG) \ + do { \ + if (reg_mask & TDX_VMCALL_REG_MASK_ ## MASK) \ + kvm_## REG ## _write(vcpu, tdx_vmcall->out_ ## REG); \ + } while (0) + + + COPY_REG(R10, r10); + COPY_REG(R11, r11); + COPY_REG(R12, r12); + COPY_REG(R13, r13); + COPY_REG(R14, r14); + COPY_REG(R15, r15); + COPY_REG(RBX, rbx); + COPY_REG(RDI, rdi); + COPY_REG(RSI, rsi); + COPY_REG(R8, r8); + COPY_REG(R9, r9); + COPY_REG(RDX, rdx); + +#undef COPY_REG + + return 1; +} + +static int tdx_vp_vmcall_to_user(struct kvm_vcpu *vcpu) +{ + struct kvm_tdx_vmcall *tdx_vmcall =3D &vcpu->run->tdx.u.vmcall; + __u64 reg_mask; + + vcpu->arch.complete_userspace_io =3D tdx_complete_vp_vmcall; + memset(tdx_vmcall, 0, sizeof(*tdx_vmcall)); + + vcpu->run->exit_reason =3D KVM_EXIT_TDX; + vcpu->run->tdx.type =3D KVM_EXIT_TDX_VMCALL; + + reg_mask =3D kvm_rcx_read(vcpu); + tdx_vmcall->reg_mask =3D reg_mask; + +#define COPY_REG(MASK, REG) \ + do { \ + if (reg_mask & TDX_VMCALL_REG_MASK_ ## MASK) { \ + tdx_vmcall->in_ ## REG =3D kvm_ ## REG ## _read(vcpu); \ + tdx_vmcall->out_ ## REG =3D tdx_vmcall->in_ ## REG; \ + } \ + } while (0) + + + COPY_REG(R10, r10); + COPY_REG(R11, r11); + COPY_REG(R12, r12); + COPY_REG(R13, r13); + COPY_REG(R14, r14); + COPY_REG(R15, r15); + COPY_REG(RBX, rbx); + COPY_REG(RDI, rdi); + COPY_REG(RSI, rsi); + COPY_REG(R8, r8); + COPY_REG(R9, r9); + COPY_REG(RDX, rdx); + +#undef COPY_REG + + /* notify userspace to handle the request */ + return 0; +} + static int handle_tdvmcall(struct kvm_vcpu *vcpu) { if (tdvmcall_exit_type(vcpu)) @@ -1022,8 +1094,16 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu) break; } =20 - tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_INVALID_OPERAND); - return 1; + /* + * Unknown VMCALL. Toss the request to the user space VMM, e.g. qemu, + * as it may know how to handle. + * + * Those VMCALLs require user space VMM: + * TDG_VP_VMCALL_REPORT_FATAL_ERROR, TDG_VP_VMCALL_MAP_GPA, + * TDG_VP_VMCALL_SETUP_EVENT_NOTIFY_INTERRUPT, and + * TDG_VP_VMCALL_GET_QUOTE. + */ + return tdx_vp_vmcall_to_user(vcpu); } =20 void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int pgd_level) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 65fc983af840..891dcfec171d 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -237,6 +237,90 @@ struct kvm_xen_exit { } u; }; =20 +struct kvm_tdx_exit { +#define KVM_EXIT_TDX_VMCALL 1 + __u32 type; + __u32 pad; + + union { + struct kvm_tdx_vmcall { + /* + * RAX(bit 0), RCX(bit 1) and RSP(bit 4) are reserved. + * RAX(bit 0): TDG.VP.VMCALL status code. + * RCX(bit 1): bitmap for used registers. + * RSP(bit 4): the caller stack. + */ +#define TDX_VMCALL_REG_MASK_RBX BIT_ULL(2) +#define TDX_VMCALL_REG_MASK_RDX BIT_ULL(3) +#define TDX_VMCALL_REG_MASK_RSI BIT_ULL(6) +#define TDX_VMCALL_REG_MASK_RDI BIT_ULL(7) +#define TDX_VMCALL_REG_MASK_R8 BIT_ULL(8) +#define TDX_VMCALL_REG_MASK_R9 BIT_ULL(9) +#define TDX_VMCALL_REG_MASK_R10 BIT_ULL(10) +#define TDX_VMCALL_REG_MASK_R11 BIT_ULL(11) +#define TDX_VMCALL_REG_MASK_R12 BIT_ULL(12) +#define TDX_VMCALL_REG_MASK_R13 BIT_ULL(13) +#define TDX_VMCALL_REG_MASK_R14 BIT_ULL(14) +#define TDX_VMCALL_REG_MASK_R15 BIT_ULL(15) + union { + __u64 in_rcx; + __u64 reg_mask; + }; + + /* + * Guest-Host-Communication Interface for TDX spec + * defines the ABI for TDG.VP.VMCALL. + */ + /* Input parameters: guest -> VMM */ + union { + __u64 in_r10; + __u64 type; + }; + union { + __u64 in_r11; + __u64 subfunction; + }; + /* + * Subfunction specific. + * Registers are used in this order to pass input + * arguments. r12=3Darg0, r13=3Darg1, etc. + */ + __u64 in_r12; + __u64 in_r13; + __u64 in_r14; + __u64 in_r15; + __u64 in_rbx; + __u64 in_rdi; + __u64 in_rsi; + __u64 in_r8; + __u64 in_r9; + __u64 in_rdx; + + /* Output parameters: VMM -> guest */ + union { + __u64 out_r10; + __u64 status_code; + }; + /* + * Subfunction specific. + * Registers are used in this order to output return + * values. r11=3Dret0, r12=3Dret1, etc. + */ + __u64 out_r11; + __u64 out_r12; + __u64 out_r13; + __u64 out_r14; + __u64 out_r15; + __u64 out_rbx; + __u64 out_rdi; + __u64 out_rsi; + __u64 out_r8; + __u64 out_r9; + __u64 out_rdx; + } vmcall; + } u; +}; + #define KVM_S390_GET_SKEYS_NONE 1 #define KVM_S390_SKEYS_MAX 1048576 =20 @@ -279,6 +363,7 @@ struct kvm_xen_exit { #define KVM_EXIT_RISCV_CSR 36 #define KVM_EXIT_NOTIFY 37 #define KVM_EXIT_MEMORY_FAULT 38 +#define KVM_EXIT_TDX 39 =20 /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -525,6 +610,8 @@ struct kvm_run { #define KVM_NOTIFY_CONTEXT_INVALID (1 << 0) __u32 flags; } notify; + /* KVM_EXIT_TDX_VMCALL */ + struct kvm_tdx_exit tdx; /* Fix the size of the union. */ char padding[256]; }; --=20 2.25.1