> diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdcall.S b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdcall.S > new file mode 100644 > index 000000000000..df9c1ed4bb2d > --- /dev/null > +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdcall.S > @@ -0,0 +1,90 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* Adapted from arch/x86/coco/tdx/tdcall.S */ > + > +#define TDX_HYPERCALL_r10 0 /* offsetof(struct tdx_hypercall_args, r10) */ > +#define TDX_HYPERCALL_r11 8 /* offsetof(struct tdx_hypercall_args, r11) */ > +#define TDX_HYPERCALL_r12 16 /* offsetof(struct tdx_hypercall_args, r12) */ > +#define TDX_HYPERCALL_r13 24 /* offsetof(struct tdx_hypercall_args, r13) */ > +#define TDX_HYPERCALL_r14 32 /* offsetof(struct tdx_hypercall_args, r14) */ > +#define TDX_HYPERCALL_r15 40 /* offsetof(struct tdx_hypercall_args, r15) */ > + > +/* > + * Bitmasks of exposed registers (with VMM). > + */ > +#define TDX_R10 0x400 > +#define TDX_R11 0x800 > +#define TDX_R12 0x1000 > +#define TDX_R13 0x2000 > +#define TDX_R14 0x4000 > +#define TDX_R15 0x8000 > + > +#define TDX_HCALL_HAS_OUTPUT 0x1 > + > +/* > + * These registers are clobbered to hold arguments for each > + * TDVMCALL. They are safe to expose to the VMM. > + * Each bit in this mask represents a register ID. Bit field > + * details can be found in TDX GHCI specification, section > + * titled "TDCALL [TDG.VP.VMCALL] leaf". > + */ > +#define TDVMCALL_EXPOSE_REGS_MASK ( TDX_R10 | TDX_R11 | \ > + TDX_R12 | TDX_R13 | \ > + TDX_R14 | TDX_R15 ) > + > +.code64 > +.section .text > + > +.globl __tdx_hypercall > +.type __tdx_hypercall, @function > +__tdx_hypercall: > + /* Set up stack frame */ > + push %rbp > + movq %rsp, %rbp > + > + /* Save callee-saved GPRs as mandated by the x86_64 ABI */ > + push %r15 > + push %r14 > + push %r13 > + push %r12 > + > + /* Mangle function call ABI into TDCALL ABI: */ > + /* Set TDCALL leaf ID (TDVMCALL (0)) in RAX */ > + xor %eax, %eax > + > + /* Copy hypercall registers from arg struct: */ > + movq TDX_HYPERCALL_r10(%rdi), %r10 > + movq TDX_HYPERCALL_r11(%rdi), %r11 > + movq TDX_HYPERCALL_r12(%rdi), %r12 > + movq TDX_HYPERCALL_r13(%rdi), %r13 > + movq TDX_HYPERCALL_r14(%rdi), %r14 > + movq TDX_HYPERCALL_r15(%rdi), %r15 > + > + movl $TDVMCALL_EXPOSE_REGS_MASK, %ecx > + > + tdcall Looks there's a missing of definition for tdcall, and will produce below error: lib/x86_64/tdx/tdcall.S:65: Error: no such instruction: `tdcall' I pulled the code https://github.com/googleprodkernel/linux-cc.git with branch tdx-selftests-rfc-v5. Fixed by adding a line in tdcall.S in my side. #define tdcall .byte 0x66,0x0f,0x01,0xcc > + > + /* TDVMCALL leaf return code is in R10 */ > + movq %r10, %rax > + > + /* Copy hypercall result registers to arg struct if needed */ > + testq $TDX_HCALL_HAS_OUTPUT, %rsi > + jz .Lout > + > + movq %r10, TDX_HYPERCALL_r10(%rdi) > + movq %r11, TDX_HYPERCALL_r11(%rdi) > + movq %r12, TDX_HYPERCALL_r12(%rdi) > + movq %r13, TDX_HYPERCALL_r13(%rdi) > + movq %r14, TDX_HYPERCALL_r14(%rdi) > + movq %r15, TDX_HYPERCALL_r15(%rdi) > +.Lout: > + /* Restore callee-saved GPRs as mandated by the x86_64 ABI */ > + pop %r12 > + pop %r13 > + pop %r14 > + pop %r15 > + > + pop %rbp > + ret > + > +/* Disable executable stack */