On 04.10.2025 00:53, Andrew Cooper wrote: > --- a/xen/arch/x86/include/asm/asm_defns.h > +++ b/xen/arch/x86/include/asm/asm_defns.h > @@ -315,6 +315,71 @@ static always_inline void stac(void) > subq $-(UREGS_error_code-UREGS_r15+\adj), %rsp > .endm > > +/* > + * Push and clear GPRs > + */ > +.macro PUSH_AND_CLEAR_GPRS > + push %rdi > + xor %edi, %edi > + push %rsi > + xor %esi, %esi > + push %rdx > + xor %edx, %edx > + push %rcx > + xor %ecx, %ecx > + push %rax > + xor %eax, %eax > + push %r8 > + xor %r8d, %r8d > + push %r9 > + xor %r9d, %r9d > + push %r10 > + xor %r10d, %r10d > + push %r11 > + xor %r11d, %r11d > + push %rbx > + xor %ebx, %ebx > + push %rbp > +#ifdef CONFIG_FRAME_POINTER > +/* Indicate special exception stack frame by inverting the frame pointer. */ > + mov %rsp, %rbp > + notq %rbp > +#else > + xor %ebp, %ebp > +#endif > + push %r12 > + xor %r12d, %r12d > + push %r13 > + xor %r13d, %r13d > + push %r14 > + xor %r14d, %r14d > + push %r15 > + xor %r15d, %r15d > +.endm > + > +/* > + * POP GPRs from a UREGS_* frame on the stack. Does not modify flags. > + * > + * @rax: Alternative destination for the %rax value on the stack. > + */ > +.macro POP_GPRS rax=%rax > + pop %r15 > + pop %r14 > + pop %r13 > + pop %r12 > + pop %rbp > + pop %rbx > + pop %r11 > + pop %r10 > + pop %r9 > + pop %r8 > + pop \rax
For placing the entry_ssp field I came back looking here. I notice there was a v2 comment regarding the rax macro parameter. Besides there being a limitation on which registers may be used, a %rsp-relative memory operand can't be (cleanly) used either. I think if you really want to retain that parameter, some warning needs adding to the comment. Jan
