From nobody Sat Feb 7 15:30:15 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 9F66F4207F; Sun, 1 Dec 2024 03:52:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733025137; cv=none; b=GG1tWzBZmI81q23F3VGmTW7J6WNyleIhXBYZ/HeIpKwtDMj0iIDw69Q/VFebFV4nhH1Y1omB+dCd1yckkZ/WZvomhJNmSmMmkQerMAv8neADS5C7+MX01RT74WDIK5yM21h7Strv/cpuVq4zLUfCh+jh2Q5vSUDcJTYGnEYb6Xk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733025137; c=relaxed/simple; bh=4S8FG+ypR0Ue5mxpFrXQ+K7j574sBZ4M9ovBehlBhdY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kT5wC+Vz3XqHq0lKrwfnU0h7WB9vlSDKHdo7dR4+6AULEoUIWaIYUOSg5WTLOIACsLgncGKQLMuS9SAyFHIJtQjWr+FW82rEVa7d/bWZVPo2P8ms+4AqAho3yimzf4KQmKv2te8zSlzuZed3CqnevYUwPkW8C8nZWlJ2Wk1acr8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=hv/RO5kv; arc=none smtp.client-ip=192.198.163.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="hv/RO5kv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1733025135; x=1764561135; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=4S8FG+ypR0Ue5mxpFrXQ+K7j574sBZ4M9ovBehlBhdY=; b=hv/RO5kvn15+2vODfyggu2N+bF8CMdYpO4/UBRy6o/QPvVu1ydJ+AiGJ 0tjyz618miUeO60iQkBS+8ae0wdWmurxFlNTLxw0/uvsnnx6vdpWos56M N8dTuqmHYUVUsCQXhsqCGNEhXCl5OXdhWvxaVg3GsMXopc7rM6MAdzdhr TpQxhPUP0/A4A22Xm6tb8PjznCKniVtB9kKhlacdh20LBJaJ2iA4qiTAQ jNHgoEG08b0+BirPiMw06827VAIyK0c9zOzBqg8la3RJf/XtTElHyx39B pGJBekNzlLIfGDdwlNfwvLQNABXYQwSqNhN5vKYIfjWjfTQEbpBmc8wos A==; X-CSE-ConnectionGUID: N8ZoiI1SSZeNkFeKmVCJ3g== X-CSE-MsgGUID: m9HUiSVVQ2m0fDEIt0xjog== X-IronPort-AV: E=McAfee;i="6700,10204,11272"; a="50725115" X-IronPort-AV: E=Sophos;i="6.12,199,1728975600"; d="scan'208";a="50725115" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Nov 2024 19:52:15 -0800 X-CSE-ConnectionGUID: aQKE0rxWQGOtlw2ZxwcAGg== X-CSE-MsgGUID: DAWP3CAcQSW/lKIjVfoffg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,199,1728975600"; d="scan'208";a="93257502" Received: from litbin-desktop.sh.intel.com ([10.239.156.93]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Nov 2024 19:52:12 -0800 From: Binbin Wu To: pbonzini@redhat.com, seanjc@google.com, kvm@vger.kernel.org Cc: rick.p.edgecombe@intel.com, kai.huang@intel.com, adrian.hunter@intel.com, reinette.chatre@intel.com, xiaoyao.li@intel.com, tony.lindgren@linux.intel.com, isaku.yamahata@intel.com, yan.y.zhao@intel.com, chao.gao@intel.com, michael.roth@amd.com, linux-kernel@vger.kernel.org, binbin.wu@linux.intel.com Subject: [PATCH 5/7] KVM: TDX: Handle TDG.VP.VMCALL Date: Sun, 1 Dec 2024 11:53:54 +0800 Message-ID: <20241201035358.2193078-6-binbin.wu@linux.intel.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20241201035358.2193078-1-binbin.wu@linux.intel.com> References: <20241201035358.2193078-1-binbin.wu@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Convert TDG.VP.VMCALL to KVM_EXIT_SYSTEM_EVENT with a new type KVM_SYSTEM_EVENT_TDX_FATAL and forward it to userspace for handling. TD guest can use TDG.VP.VMCALL to report the fatal error it has experienced. This hypercall is special because TD guest is requesting a termination with the error information, KVM needs to forward the hypercall to userspace anyway, KVM doesn't do sanity checks and let userspace decide what to do. Signed-off-by: Binbin Wu --- Hypercalls exit to userspace breakout: - New added. Implement one of the hypercalls need to exit to userspace for handling af= ter reverting "KVM: TDX: Add KVM Exit for TDX TDG.VP.VMCALL", which tries to = resolve Sean's comment. https://lore.kernel.org/kvm/Zg18ul8Q4PGQMWam@google.com/ - Use TDVMCALL_STATUS prefix for TDX call status codes (Binbin) --- Documentation/virt/kvm/api.rst | 8 ++++++ arch/x86/kvm/vmx/tdx.c | 50 ++++++++++++++++++++++++++++++++++ include/uapi/linux/kvm.h | 1 + 3 files changed, 59 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index edc070c6e19b..bb39da72c647 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6815,6 +6815,7 @@ should put the acknowledged interrupt vector into the= 'epr' field. #define KVM_SYSTEM_EVENT_WAKEUP 4 #define KVM_SYSTEM_EVENT_SUSPEND 5 #define KVM_SYSTEM_EVENT_SEV_TERM 6 + #define KVM_SYSTEM_EVENT_TDX_FATAL 7 __u32 type; __u32 ndata; __u64 data[16]; @@ -6841,6 +6842,13 @@ Valid values for 'type' are: reset/shutdown of the VM. - KVM_SYSTEM_EVENT_SEV_TERM -- an AMD SEV guest requested termination. The guest physical address of the guest's GHCB is stored in `data[0]`. + - KVM_SYSTEM_EVENT_TDX_FATAL -- an TDX guest requested termination. + The error codes of the guest's GHCI is stored in `data[0]`. + If the bit 63 of `data[0]` is set, it indicates there is TD specified + additional information provided in a page, which is shared memory. The + guest physical address of the information page is stored in `data[1]`. + An optional error message is provided by `data[2]` ~ `data[9]`, which is + byte sequence, LSB filled first. Typically, ASCII code(0x20-0x7e) is fi= lled. - KVM_SYSTEM_EVENT_WAKEUP -- the exiting vCPU is in a suspended state and KVM has recognized a wakeup event. Userspace may honor this event by marking the exiting vCPU as runnable, or deny it and call KVM_RUN again. diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 553f4cbe0693..a79f9ca962d1 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1093,6 +1093,54 @@ static int tdx_map_gpa(struct kvm_vcpu *vcpu) return 1; } =20 +static int tdx_report_fatal_error(struct kvm_vcpu *vcpu) +{ + u64 reg_mask =3D kvm_rcx_read(vcpu); + u64* opt_regs; + + /* + * Skip sanity checks and let userspace decide what to do if sanity + * checks fail. + */ + vcpu->run->exit_reason =3D KVM_EXIT_SYSTEM_EVENT; + vcpu->run->system_event.type =3D KVM_SYSTEM_EVENT_TDX_FATAL; + vcpu->run->system_event.ndata =3D 10; + /* Error codes. */ + vcpu->run->system_event.data[0] =3D tdvmcall_a0_read(vcpu); + /* GPA of additional information page. */ + vcpu->run->system_event.data[1] =3D tdvmcall_a1_read(vcpu); + /* Information passed via registers (up to 64 bytes). */ + opt_regs =3D &vcpu->run->system_event.data[2]; + +#define COPY_REG(REG, MASK) \ + do { \ + if (reg_mask & MASK) \ + *opt_regs =3D kvm_ ## REG ## _read(vcpu); \ + else \ + *opt_regs =3D 0; \ + opt_regs++; \ + } while (0) + + /* The order is defined in GHCI. */ + COPY_REG(r14, BIT_ULL(14)); + COPY_REG(r15, BIT_ULL(15)); + COPY_REG(rbx, BIT_ULL(3)); + COPY_REG(rdi, BIT_ULL(7)); + COPY_REG(rsi, BIT_ULL(6)); + COPY_REG(r8, BIT_ULL(8)); + COPY_REG(r9, BIT_ULL(9)); + COPY_REG(rdx, BIT_ULL(2)); + + /* + * Set the status code according to GHCI spec, although the vCPU may + * not return back to guest. + */ + tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_SUCCESS); + + /* Forward request to userspace. */ + return 0; +} + static int handle_tdvmcall(struct kvm_vcpu *vcpu) { if (tdvmcall_exit_type(vcpu)) @@ -1101,6 +1149,8 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu) switch (tdvmcall_leaf(vcpu)) { case TDVMCALL_MAP_GPA: return tdx_map_gpa(vcpu); + case TDVMCALL_REPORT_FATAL_ERROR: + return tdx_report_fatal_error(vcpu); default: break; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 637efc055145..c173c8dfcf83 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -375,6 +375,7 @@ struct kvm_run { #define KVM_SYSTEM_EVENT_WAKEUP 4 #define KVM_SYSTEM_EVENT_SUSPEND 5 #define KVM_SYSTEM_EVENT_SEV_TERM 6 +#define KVM_SYSTEM_EVENT_TDX_FATAL 7 __u32 type; __u32 ndata; union { --=20 2.46.0