From: Denis Mukhin <dmuk...@ford.com> Improve error handling in VMX wrappers by switching to `asm goto()` where possible.
Resolves: https://gitlab.com/xen-project/xen/-/work_items/210 Signed-off-by: Denis Mukhin <dmuk...@ford.com> --- Changes since v2: - dropped vmread changes - checked \n\t formatting - Link to v2: https://lore.kernel.org/xen-devel/20250403182250.3329498-7-dmuk...@ford.com/ --- xen/arch/x86/include/asm/hvm/vmx/vmx.h | 122 +++++++++++++------------ 1 file changed, 64 insertions(+), 58 deletions(-) diff --git a/xen/arch/x86/include/asm/hvm/vmx/vmx.h b/xen/arch/x86/include/asm/hvm/vmx/vmx.h index affb3a8bd6..6aa6e1f212 100644 --- a/xen/arch/x86/include/asm/hvm/vmx/vmx.h +++ b/xen/arch/x86/include/asm/hvm/vmx/vmx.h @@ -294,28 +294,30 @@ extern uint8_t posted_intr_vector; static always_inline void __vmptrld(u64 addr) { - asm volatile ( "vmptrld %0\n\t" - /* 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\t" + "jbe %l[vmfail]\n" + : + : [addr] "m" (addr) + : "memory" + : vmfail ); + return; + + vmfail: + BUG(); } static always_inline void __vmpclear(u64 addr) { - asm volatile ( "vmclear %0\n\t" - /* 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\t" + "jbe %l[vmfail]\n" + : + : [addr] "m" (addr) + : "memory" + : vmfail ); + return; + + vmfail: + BUG(); } static always_inline void __vmread(unsigned long field, unsigned long *value) @@ -332,14 +334,16 @@ static always_inline void __vmread(unsigned long field, unsigned long *value) 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" + : + : [field] "r" (field), [value] "rm" (value) + : + : vmfail ); + return; + + vmfail: + BUG(); } static inline enum vmx_insn_errno vmread_safe(unsigned long field, @@ -367,22 +371,22 @@ 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" + : + : [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; } @@ -400,15 +404,16 @@ 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\t" - /* 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\t" + "jbe %l[vmfail]\n" + : + : [operand] "m" (operand), [type] "r" (type) + : "memory" + : vmfail ); + return; + + vmfail: + BUG(); } static always_inline void __invvpid(unsigned long type, u16 vpid, u64 gva) @@ -420,16 +425,17 @@ 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\t" - /* 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\t" + " jbe %l[vmfail]\n" + "2:" _ASM_EXTABLE(1b, 2b) + : + : [operand] "m" (operand), [type] "r" (type) + : "memory" + : vmfail ); + return; + + vmfail: + BUG(); } static inline void ept_sync_all(void) -- 2.34.1
