cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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tdx.c (1458B)

      1// SPDX-License-Identifier: GPL-2.0
      2
      3#include "../cpuflags.h"
      4#include "../string.h"
      5#include "../io.h"
      6#include "error.h"
      7
      8#include <vdso/limits.h>
      9#include <uapi/asm/vmx.h>
     10
     11#include <asm/shared/tdx.h>
     12
     13/* Called from __tdx_hypercall() for unrecoverable failure */
     14void __tdx_hypercall_failed(void)
     15{
     16	error("TDVMCALL failed. TDX module bug?");
     17}
     18
     19static inline unsigned int tdx_io_in(int size, u16 port)
     20{
     21	struct tdx_hypercall_args args = {
     22		.r10 = TDX_HYPERCALL_STANDARD,
     23		.r11 = EXIT_REASON_IO_INSTRUCTION,
     24		.r12 = size,
     25		.r13 = 0,
     26		.r14 = port,
     27	};
     28
     29	if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT))
     30		return UINT_MAX;
     31
     32	return args.r11;
     33}
     34
     35static inline void tdx_io_out(int size, u16 port, u32 value)
     36{
     37	struct tdx_hypercall_args args = {
     38		.r10 = TDX_HYPERCALL_STANDARD,
     39		.r11 = EXIT_REASON_IO_INSTRUCTION,
     40		.r12 = size,
     41		.r13 = 1,
     42		.r14 = port,
     43		.r15 = value,
     44	};
     45
     46	__tdx_hypercall(&args, 0);
     47}
     48
     49static inline u8 tdx_inb(u16 port)
     50{
     51	return tdx_io_in(1, port);
     52}
     53
     54static inline void tdx_outb(u8 value, u16 port)
     55{
     56	tdx_io_out(1, port, value);
     57}
     58
     59static inline void tdx_outw(u16 value, u16 port)
     60{
     61	tdx_io_out(2, port, value);
     62}
     63
     64void early_tdx_detect(void)
     65{
     66	u32 eax, sig[3];
     67
     68	cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, &sig[0], &sig[2],  &sig[1]);
     69
     70	if (memcmp(TDX_IDENT, sig, sizeof(sig)))
     71		return;
     72
     73	/* Use hypercalls instead of I/O instructions */
     74	pio_ops.f_inb  = tdx_inb;
     75	pio_ops.f_outb = tdx_outb;
     76	pio_ops.f_outw = tdx_outw;
     77}