From patchwork Mon Jan 22 23:54:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Isaku Yamahata X-Patchwork-Id: 13526518 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 890DF6A32F; Mon, 22 Jan 2024 23:55:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.55.52.120 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705967762; cv=none; b=JOMr0zXTBmpdahBvqK/jXrMqT3eJLzZbTz9P5uCkzNkbrhj+ByoeaOEFAT4EbXkUtGCfwfjQud2nXScCGQSfVPuz5hnaNBP0c+OK3A901zHweUdY2V9y9nukDpOLkX+aLBB2ojiHpYiuuHVuZt3qz3XJMNP7uYbgwqqwbA5vQIw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705967762; c=relaxed/simple; bh=/2cJxNvusE/3zgxZMVpeLxjUmoTXoYYWyne2kQS1Phg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=AADGEq6TBnxCpI3baeq3fK4RWgguEmgm1A0+wwT5LAYGnL0oUqxUpG/wh1l5y4WLLPQAR20e9P1s1GPvXEizxoWuTZx5ZJ8K5wh3lqABiynJs29Wu3fMl97t2OnaB4IkFhuUt3Twa5eBEBQ2EqrZ+BsUI+bZfEHkJS/hX5VG5G8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=SMrtg2o3; arc=none smtp.client-ip=192.55.52.120 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="SMrtg2o3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1705967759; x=1737503759; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=/2cJxNvusE/3zgxZMVpeLxjUmoTXoYYWyne2kQS1Phg=; b=SMrtg2o3gQ/1uJQ1WNUcLsESxaTqJfm8cBPyz4ZjgU7vcuxCwQQDgdu5 bn2NuYn9yXyIvnz9ogbM98IBWm+pVIs3MH6BtR6bsTapOLG6c8YMpChej yUiiFdfwe7Y3EO1bJczqp83BNtv5LOkWjrcsmmDDuoiHSvSIf/UgGkEiu KiPslCb2g6ebVRMSS4Euc+PApKtdu64OP1meB6axGJoF9WNFElfegakgd Jx+5Usd2YyGkFQXGw63Es/yZPIID1M43HKv/W8So364RzDjstQ6DxMsoo rqu5nKagx8Za42EWq3qNjlQXTPnyD2h0BsHB3R32IwCKcRNxFG7xUQcqG Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10961"; a="400217850" X-IronPort-AV: E=Sophos;i="6.05,212,1701158400"; d="scan'208";a="400217850" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jan 2024 15:55:50 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,212,1701158400"; d="scan'208";a="27817969" Received: from ls.sc.intel.com (HELO localhost) ([172.25.112.31]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jan 2024 15:55:50 -0800 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 , Kai Huang , chen.bo@intel.com, hang.yuan@intel.com, tina.zhang@intel.com Subject: [PATCH v18 095/121] KVM: TDX: Add KVM Exit for TDX TDG.VP.VMCALL Date: Mon, 22 Jan 2024 15:54:11 -0800 Message-Id: <576e3c6ca9fa4db50185ee0258546039d290f8ab.1705965635.git.isaku.yamahata@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 | 89 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 171 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index d922e3786163..c504c5d9debf 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1088,6 +1088,78 @@ static int tdx_emulate_vmcall(struct kvm_vcpu *vcpu) return 1; } +static int tdx_complete_vp_vmcall(struct kvm_vcpu *vcpu) +{ + struct kvm_tdx_vmcall *tdx_vmcall = &vcpu->run->tdx.u.vmcall; + __u64 reg_mask = 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 = &vcpu->run->tdx.u.vmcall; + __u64 reg_mask; + + vcpu->arch.complete_userspace_io = tdx_complete_vp_vmcall; + memset(tdx_vmcall, 0, sizeof(*tdx_vmcall)); + + vcpu->run->exit_reason = KVM_EXIT_TDX; + vcpu->run->tdx.type = KVM_EXIT_TDX_VMCALL; + + reg_mask = kvm_rcx_read(vcpu); + tdx_vmcall->reg_mask = reg_mask; + +#define COPY_REG(MASK, REG) \ + do { \ + if (reg_mask & TDX_VMCALL_REG_MASK_ ## MASK) { \ + tdx_vmcall->in_ ## REG = kvm_ ## REG ## _read(vcpu); \ + tdx_vmcall->out_ ## REG = 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)) @@ -1098,8 +1170,16 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu) break; } - 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); } 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 c3308536482b..8426c506ac04 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -167,6 +167,92 @@ struct kvm_xen_exit { } u; }; +/* masks for reg_mask to indicate which registers are passed. */ +#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) + +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. + */ + 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=arg0, r13=arg1, 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=ret0, r12=ret1, 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 @@ -210,6 +296,7 @@ struct kvm_xen_exit { #define KVM_EXIT_NOTIFY 37 #define KVM_EXIT_LOONGARCH_IOCSR 38 #define KVM_EXIT_MEMORY_FAULT 39 +#define KVM_EXIT_TDX 40 /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -470,6 +557,8 @@ struct kvm_run { __u64 gpa; __u64 size; } memory_fault; + /* KVM_EXIT_TDX_VMCALL */ + struct kvm_tdx_exit tdx; /* Fix the size of the union. */ char padding[256]; };