From patchwork Thu Apr 3 18:23:32 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Denis Mukhin X-Patchwork-Id: 14037511 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3C9BDC3600C for ; Thu, 3 Apr 2025 18:31:30 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.937117.1338177 (Exim 4.92) (envelope-from ) id 1u0PLS-0006LS-Hp; Thu, 03 Apr 2025 18:31:18 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 937117.1338177; Thu, 03 Apr 2025 18:31:18 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u0PLS-0006LL-Dn; Thu, 03 Apr 2025 18:31:18 +0000 Received: by outflank-mailman (input) for mailman id 937117; Thu, 03 Apr 2025 18:31:16 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u0PE6-0001N1-A1 for xen-devel@lists.xenproject.org; Thu, 03 Apr 2025 18:23:42 +0000 Received: from mail-4316.protonmail.ch (mail-4316.protonmail.ch [185.70.43.16]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id c31d4645-10b8-11f0-9ffb-bf95429c2676; Thu, 03 Apr 2025 20:23:38 +0200 (CEST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: c31d4645-10b8-11f0-9ffb-bf95429c2676 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=proton.me; s=protonmail; t=1743704617; x=1743963817; bh=D9HZ36OBMZA9sIUaGxeMjO+UOWm/VDTojn44aNu2MRk=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector:List-Unsubscribe:List-Unsubscribe-Post; b=e4hZb91LzXNCKy1yuTR+9aIzDdgYcKNqmytcq179tyDuwTc6KaVHptwjKxt6rDOgS 6vexmk8eVMhjjV0Td+ch6AhW8DOyblH44eyR2hJZC8qmdd2b6H9EaTUR8nH8mtkpEU ed6TvuMgm5/IwluVrFFYtocZlJv2KpFxPsjfqNCLISF6s3nDuXE3EOGgDkIiE8NoVF mF7b5Um7ycacVTAuisSbwzKuC71tO7/B+1RzPAF+L0Q4zsQdYswrlF8cn6PVQqn2p5 shI2XF0GDLp2n625HN5zWIewNVOKHlJ4d4wKc7n1EpWT3g1UDQU93zxyiqwRfo+Ufh qPO69uGACudmg== Date: Thu, 03 Apr 2025 18:23:32 +0000 To: xen-devel@lists.xenproject.org From: dmkhn@proton.me Cc: andrew.cooper3@citrix.com, anthony.perard@vates.tech, jbeulich@suse.com, julien@xen.org, michal.orzel@amd.com, roger.pau@citrix.com, sstabellini@kernel.org, dmukhin@ford.com Subject: [PATCH v2 6/6] x86/vmx: rework VMX wrappers to use `asm goto()` Message-ID: <20250403182250.3329498-7-dmukhin@ford.com> In-Reply-To: <20250403182250.3329498-1-dmukhin@ford.com> References: <20250403182250.3329498-1-dmukhin@ford.com> Feedback-ID: 123220910:user:proton X-Pm-Message-ID: a796a4a4237e8e45901dcb32a84db62739145c57 MIME-Version: 1.0 From: Denis Mukhin Improve error handling in VMX wrappers by switching to `asm goto()` where possible. vmread_safe() kept as is because the minimally required baseline GCC does not support output operands in `asm goto`. Resolves: https://gitlab.com/xen-project/xen/-/work_items/210 Signed-off-by: Denis Mukhin --- xen/arch/x86/include/asm/hvm/vmx/vmx.h | 141 +++++++++++++------------ 1 file changed, 73 insertions(+), 68 deletions(-) diff --git a/xen/arch/x86/include/asm/hvm/vmx/vmx.h b/xen/arch/x86/include/asm/hvm/vmx/vmx.h index ed6a6986b9..19d41f7b90 100644 --- a/xen/arch/x86/include/asm/hvm/vmx/vmx.h +++ b/xen/arch/x86/include/asm/hvm/vmx/vmx.h @@ -294,54 +294,57 @@ extern uint8_t posted_intr_vector; static always_inline void __vmptrld(u64 addr) { - asm volatile ( "vmptrld %0\n" - /* CF==1 or ZF==1 --> BUG() */ - UNLIKELY_START(be, vmptrld) - _ASM_BUGFRAME_TEXT(0) - UNLIKELY_END_SECTION - : - : "m" (addr), - _ASM_BUGFRAME_INFO(BUGFRAME_bug, __LINE__, __FILE__, 0) - : "memory" ); + asm goto ( "vmptrld %[addr]\n" + "jbe %l[vmfail]\n\t" + : + : [addr] "m" (addr) + : "memory" + : vmfail ); + return; + + vmfail: + BUG(); } static always_inline void __vmpclear(u64 addr) { - asm volatile ( "vmclear %0\n" - /* CF==1 or ZF==1 --> BUG() */ - UNLIKELY_START(be, vmclear) - _ASM_BUGFRAME_TEXT(0) - UNLIKELY_END_SECTION - : - : "m" (addr), - _ASM_BUGFRAME_INFO(BUGFRAME_bug, __LINE__, __FILE__, 0) - : "memory" ); + asm goto ( "vmclear %[addr]\n" + "jbe %l[vmfail]\n\t" + : + : [addr] "m" (addr) + : "memory" + : vmfail ); + return; + + vmfail: + BUG(); } static always_inline void __vmread(unsigned long field, unsigned long *value) { - asm volatile ( "vmread %1, %0\n\t" - /* CF==1 or ZF==1 --> BUG() */ - UNLIKELY_START(be, vmread) - _ASM_BUGFRAME_TEXT(0) - UNLIKELY_END_SECTION - : "=rm" (*value) - : "r" (field), - _ASM_BUGFRAME_INFO(BUGFRAME_bug, __LINE__, __FILE__, 0) - ); + bool vmfail; + + asm volatile ( "vmread %[field], %[value]\n\t" + "setbe %[vmfail]\n\t" + : [value] "=rm" (*value), [vmfail] "=rm" (vmfail) + : [field] "r" (field) + : "cc" ); + if ( vmfail ) + BUG(); } static always_inline void __vmwrite(unsigned long field, unsigned long value) { - asm volatile ( "vmwrite %1, %0\n" - /* CF==1 or ZF==1 --> BUG() */ - UNLIKELY_START(be, vmwrite) - _ASM_BUGFRAME_TEXT(0) - UNLIKELY_END_SECTION - : - : "r" (field) , "rm" (value), - _ASM_BUGFRAME_INFO(BUGFRAME_bug, __LINE__, __FILE__, 0) - ); + asm goto ( "vmwrite %[value], %[field]\n\t" + "jbe %l[vmfail]\n\t" + : + : [field] "r" (field), [value] "rm" (value) + : + : vmfail ); + return; + + vmfail: + BUG(); } static inline enum vmx_insn_errno vmread_safe(unsigned long field, @@ -369,22 +372,22 @@ static inline enum vmx_insn_errno vmread_safe(unsigned long field, static inline enum vmx_insn_errno vmwrite_safe(unsigned long field, unsigned long value) { - unsigned long ret = VMX_INSN_SUCCEED; - bool fail_invalid, fail_valid; + unsigned long ret; - asm volatile ( "vmwrite %[value], %[field]\n\t" - ASM_FLAG_OUT(, "setc %[invalid]\n\t") - ASM_FLAG_OUT(, "setz %[valid]\n\t") - : ASM_FLAG_OUT("=@ccc", [invalid] "=rm") (fail_invalid), - ASM_FLAG_OUT("=@ccz", [valid] "=rm") (fail_valid) - : [field] "r" (field), - [value] "rm" (value) ); + asm goto ( "vmwrite %[value], %[field]\n\t" + "jc %l[vmfail_invalid]\n\t" + "jz %l[vmfail_error]\n\t" + : + : [field] "r" (field), [value] "rm" (value) + : + : vmfail_invalid, vmfail_error ); + return VMX_INSN_SUCCEED; - if ( unlikely(fail_invalid) ) - ret = VMX_INSN_FAIL_INVALID; - else if ( unlikely(fail_valid) ) - __vmread(VM_INSTRUCTION_ERROR, &ret); + vmfail_invalid: + return VMX_INSN_FAIL_INVALID; + vmfail_error: + __vmread(VM_INSTRUCTION_ERROR, &ret); return ret; } @@ -402,15 +405,16 @@ static always_inline void __invept(unsigned long type, uint64_t eptp) !cpu_has_vmx_ept_invept_single_context ) type = INVEPT_ALL_CONTEXT; - asm volatile ( "invept %0, %1\n" - /* CF==1 or ZF==1 --> BUG() */ - UNLIKELY_START(be, invept) - _ASM_BUGFRAME_TEXT(0) - UNLIKELY_END_SECTION - : - : "m" (operand), "r" (type), - _ASM_BUGFRAME_INFO(BUGFRAME_bug, __LINE__, __FILE__, 0) - : "memory" ); + asm goto ( "invept %[operand], %[type]\n" + "jbe %l[vmfail]\n\t" + : + : [operand] "m" (operand), [type] "r" (type) + : "memory" + : vmfail ); + return; + + vmfail: + BUG(); } static always_inline void __invvpid(unsigned long type, u16 vpid, u64 gva) @@ -422,16 +426,17 @@ static always_inline void __invvpid(unsigned long type, u16 vpid, u64 gva) } operand = {vpid, 0, gva}; /* Fix up #UD exceptions which occur when TLBs are flushed before VMXON. */ - asm volatile ( "1: invvpid %0, %1\n" - /* CF==1 or ZF==1 --> BUG() */ - UNLIKELY_START(be, invvpid) - _ASM_BUGFRAME_TEXT(0) - UNLIKELY_END_SECTION "\n" - "2:" _ASM_EXTABLE(1b, 2b) - : - : "m" (operand), "r" (type), - _ASM_BUGFRAME_INFO(BUGFRAME_bug, __LINE__, __FILE__, 0) - : "memory" ); + asm goto ( "1: invvpid %[operand], %[type]\n" + " jbe %l[vmfail]\n\t" + "2:" _ASM_EXTABLE(1b, 2b) + : + : [operand] "m" (operand), [type] "r" (type) + : "memory" + : vmfail ); + return; + + vmfail: + BUG(); } static inline void ept_sync_all(void)