linux-zen-server/arch/x86/boot/compressed/tdx.c

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2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0
#include "../cpuflags.h"
#include "../string.h"
#include "../io.h"
#include "error.h"
#include <vdso/limits.h>
#include <uapi/asm/vmx.h>
#include <asm/shared/tdx.h>
/* Called from __tdx_hypercall() for unrecoverable failure */
void __tdx_hypercall_failed(void)
{
error("TDVMCALL failed. TDX module bug?");
}
static inline unsigned int tdx_io_in(int size, u16 port)
{
struct tdx_hypercall_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = EXIT_REASON_IO_INSTRUCTION,
.r12 = size,
.r13 = 0,
.r14 = port,
};
if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT))
return UINT_MAX;
return args.r11;
}
static inline void tdx_io_out(int size, u16 port, u32 value)
{
struct tdx_hypercall_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = EXIT_REASON_IO_INSTRUCTION,
.r12 = size,
.r13 = 1,
.r14 = port,
.r15 = value,
};
__tdx_hypercall(&args, 0);
}
static inline u8 tdx_inb(u16 port)
{
return tdx_io_in(1, port);
}
static inline void tdx_outb(u8 value, u16 port)
{
tdx_io_out(1, port, value);
}
static inline void tdx_outw(u16 value, u16 port)
{
tdx_io_out(2, port, value);
}
void early_tdx_detect(void)
{
u32 eax, sig[3];
cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, &sig[0], &sig[2], &sig[1]);
if (memcmp(TDX_IDENT, sig, sizeof(sig)))
return;
/* Use hypercalls instead of I/O instructions */
pio_ops.f_inb = tdx_inb;
pio_ops.f_outb = tdx_outb;
pio_ops.f_outw = tdx_outw;
}