From patchwork Tue Feb 11 02:54:40 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Binbin Wu X-Patchwork-Id: 13969234 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (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 1F5DF1D61A5; Tue, 11 Feb 2025 02:53:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.15 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739242408; cv=none; b=C08JkLbbjyh1Ln9wpky8PtpGqE1HWatza6NA/eDQhmUqSsXShLmF58dyFkTuGyIhzrS4R5l8txn9z+9HfKq/xflBM/1L+KgMQLpQPAuGCZzwDsfjsAlpfb2zQKZIxeBafkwTn92OAnpQYn1PMPIaLQPUBw8nxm9EKF+Xp6ejZOg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739242408; c=relaxed/simple; bh=YMWpCMl+AIpwqEPlHAIvt12kPvItzQgcwNKb/CTy/5I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nkqCpOlEizvMIpBnCL9tyEOzE7vxsIcn7x/Z9WVNggfuQWs1Jc0ZHKWsgyIRB8Nujy6LV6nvVejjxda/RNWuR0G89CINIP1UUyjDPVynKuAGvmDeTKqS/v1eIy1OZzvxWL3Q3lWASXVzkt6h63PT/jBSqPSkIj9dYqW7+uHyi/E= 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=PYo3keyw; arc=none smtp.client-ip=198.175.65.15 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="PYo3keyw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1739242408; x=1770778408; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=YMWpCMl+AIpwqEPlHAIvt12kPvItzQgcwNKb/CTy/5I=; b=PYo3keywFZuHhtyfJjaOAbRxhhZLvvS+ej9vwCj4gN3r/1Pur2GfJDxu 8B31hETTN5YfshOraIzHmxAfN7fff7nOhNK7PmxR7n4FwUd+dEzERzCpy yT+VNnKFGnZpL9Xu8bOfMUYl00AEM32f+xSOhHzgo6i88sxxOYl60eNMq j42rpPu/NzE9AmdYkKTz1vNgcMEcj+QATO09Pxau4Igl4ZtS/dEEDthNP ou194tgKXP/AqDTzOkQlrEK3RotA6wIB8Hif8Ntf1vVzemgrkXFUTLUeB ULxqtewngai1yKBpRjJH+20i0p0QTBWsLM8G5aA4OzDwnXCMjlu8eVDal Q==; X-CSE-ConnectionGUID: 7xrK4v4KQFykzmtR29uI/w== X-CSE-MsgGUID: X9WEOIB0SN6w/MpnO7dwJg== X-IronPort-AV: E=McAfee;i="6700,10204,11341"; a="43506625" X-IronPort-AV: E=Sophos;i="6.13,276,1732608000"; d="scan'208";a="43506625" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2025 18:53:28 -0800 X-CSE-ConnectionGUID: pKk/uTvFQQmRDSQX+ZEBuw== X-CSE-MsgGUID: tVbpFlurSnmVyd1gc+sG6g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="112236456" Received: from litbin-desktop.sh.intel.com ([10.239.156.93]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2025 18:53:23 -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@intel.com, isaku.yamahata@intel.com, yan.y.zhao@intel.com, chao.gao@intel.com, linux-kernel@vger.kernel.org, binbin.wu@linux.intel.com Subject: [PATCH v2 6/8] KVM: TDX: Handle TDG.VP.VMCALL Date: Tue, 11 Feb 2025 10:54:40 +0800 Message-ID: <20250211025442.3071607-7-binbin.wu@linux.intel.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20250211025442.3071607-1-binbin.wu@linux.intel.com> References: <20250211025442.3071607-1-binbin.wu@linux.intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 v2: - Use vp_enter_args instead of x86 registers. - vcpu->run->system_event.ndata is not hardcoded to 10. (Xiaoyao) - Undefine COPY_REG after use. (Yilun) - Updated the document about KVM_SYSTEM_EVENT_TDX_FATAL. (Chao) Hypercalls exit to userspace v1: - New added. Implement one of the hypercalls need to exit to userspace for handling after 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 | 9 +++++++ arch/x86/kvm/vmx/tdx.c | 45 ++++++++++++++++++++++++++++++++++ include/uapi/linux/kvm.h | 1 + 3 files changed, 55 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 2ba70c1fad51..5e415b312ab0 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6823,6 +6823,7 @@ 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]; @@ -6849,6 +6850,14 @@ 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 -- a TDX guest reported a fatal error state. + The error code reported by the TDX guest is stored in `data[0]`, the error + code format is defined in TDX GHCI specification. + 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 filled. - 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 8b51b4c937e9..85956768c515 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1092,11 +1092,56 @@ static int tdx_map_gpa(struct kvm_vcpu *vcpu) return 1; } +static int tdx_report_fatal_error(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + u64 reg_mask = tdx->vp_enter_args.rcx; + u64 *opt_regs; + + /* + * Skip sanity checks and let userspace decide what to do if sanity + * checks fail. + */ + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; + vcpu->run->system_event.type = KVM_SYSTEM_EVENT_TDX_FATAL; + /* Error codes. */ + vcpu->run->system_event.data[0] = tdx->vp_enter_args.r12; + /* GPA of additional information page. */ + vcpu->run->system_event.data[1] = tdx->vp_enter_args.r13; + /* Information passed via registers (up to 64 bytes). */ + opt_regs = &vcpu->run->system_event.data[2]; + +#define COPY_REG(REG, MASK) \ + do { \ + if (reg_mask & MASK) { \ + *opt_regs = tdx->vp_enter_args.REG; \ + 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)); +#undef COPY_REG + + vcpu->run->system_event.ndata = opt_regs - vcpu->run->system_event.data; + + return 0; +} + 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 45e6d8fca9b9..937400350317 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 {