On Wed, Jul 12, 2023 at 08:55:24PM +1200, Kai Huang wrote: > @@ -85,6 +86,7 @@ > .endif /* \saved */ > > .if \host > +1: > seamcall > /* > * SEAMCALL instruction is essentially a VMExit from VMX root > @@ -99,6 +101,7 @@ > */ > mov $TDX_SEAMCALL_VMFAILINVALID, %rdi > cmovc %rdi, %rax > +2: > .else > tdcall > .endif This is just wrong, if the thing traps you should not do the return registers. And at this point the mov/cmovc thing doesn't make much sense either. > @@ -185,4 +188,21 @@ > > FRAME_END > RET > + > + .if \host > +3: > + /* > + * SEAMCALL caused #GP or #UD. By reaching here %eax contains > + * the trap number. Convert the trap number to the TDX error > + * code by setting TDX_SW_ERROR to the high 32-bits of %rax. > + * > + * Note cannot OR TDX_SW_ERROR directly to %rax as OR instruction > + * only accepts 32-bit immediate at most. > + */ > + movq $TDX_SW_ERROR, %r12 > + orq %r12, %rax > + jmp 2b > + > + _ASM_EXTABLE_FAULT(1b, 3b) > + .endif /* \host */ > .endm Also, please used named labels where possible and *please* keep asm directives unindented. --- a/arch/x86/virt/vmx/tdx/tdxcall.S +++ b/arch/x86/virt/vmx/tdx/tdxcall.S @@ -56,7 +56,7 @@ movq TDX_MODULE_r10(%rsi), %r10 movq TDX_MODULE_r11(%rsi), %r11 - .if \saved +.if \saved /* * Move additional input regs from the structure. For simplicity * assume that anything needs the callee-saved regs also tramples @@ -75,18 +75,18 @@ movq TDX_MODULE_r15(%rsi), %r15 movq TDX_MODULE_rbx(%rsi), %rbx - .if \ret +.if \ret /* Save the structure pointer as %rsi is about to be clobbered */ pushq %rsi - .endif +.endif movq TDX_MODULE_rdi(%rsi), %rdi /* %rsi needs to be done at last */ movq TDX_MODULE_rsi(%rsi), %rsi - .endif /* \saved */ +.endif /* \saved */ - .if \host -1: +.if \host +.Lseamcall: seamcall /* * SEAMCALL instruction is essentially a VMExit from VMX root @@ -99,15 +99,13 @@ * This value will never be used as actual SEAMCALL error code as * it is from the Reserved status code class. */ - mov $TDX_SEAMCALL_VMFAILINVALID, %rdi - cmovc %rdi, %rax -2: - .else + jc .Lseamfail +.else tdcall - .endif +.endif - .if \ret - .if \saved +.if \ret +.if \saved /* * Restore the structure from stack to saved the output registers * @@ -136,7 +134,7 @@ movq %r15, TDX_MODULE_r15(%rsi) movq %rbx, TDX_MODULE_rbx(%rsi) movq %rdi, TDX_MODULE_rdi(%rsi) - .endif /* \saved */ +.endif /* \saved */ /* Copy output regs to the structure */ movq %rcx, TDX_MODULE_rcx(%rsi) @@ -145,10 +143,11 @@ movq %r9, TDX_MODULE_r9(%rsi) movq %r10, TDX_MODULE_r10(%rsi) movq %r11, TDX_MODULE_r11(%rsi) - .endif /* \ret */ +.endif /* \ret */ - .if \saved - .if \ret +.Lout: +.if \saved +.if \ret /* * Clear registers shared by guest for VP.ENTER and VP.VMCALL to * prevent speculative use of values from guest/VMM, including @@ -170,13 +169,8 @@ xorq %r9, %r9 xorq %r10, %r10 xorq %r11, %r11 - xorq %r12, %r12 - xorq %r13, %r13 - xorq %r14, %r14 - xorq %r15, %r15 - xorq %rbx, %rbx xorq %rdi, %rdi - .endif /* \ret */ +.endif /* \ret */ /* Restore callee-saved GPRs as mandated by the x86_64 ABI */ popq %r15 @@ -184,13 +178,17 @@ popq %r13 popq %r12 popq %rbx - .endif /* \saved */ +.endif /* \saved */ FRAME_END RET - .if \host -3: +.if \host +.Lseamfail: + mov $TDX_SEAMCALL_VMFAILINVALID, %rax + jmp .Lout + +.Lseamtrap: /* * SEAMCALL caused #GP or #UD. By reaching here %eax contains * the trap number. Convert the trap number to the TDX error @@ -201,8 +199,8 @@ */ movq $TDX_SW_ERROR, %r12 orq %r12, %rax - jmp 2b + jmp .Lout - _ASM_EXTABLE_FAULT(1b, 3b) - .endif /* \host */ + _ASM_EXTABLE_FAULT(.Lseamcall, .Lseamtrap) +.endif /* \host */ .endm
