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// SPDX-License-Identifier: GPL-2.0-only
#ifndef __SELFTESTS_X86_XSTATE_H
#define __SELFTESTS_X86_XSTATE_H
#include <stdint.h>
#include "../kselftest.h"
#define XSAVE_HDR_OFFSET 512
#define XSAVE_HDR_SIZE 64
/*
* List of XSAVE features Linux knows about. Copied from
* arch/x86/include/asm/fpu/types.h
*/
enum xfeature {
XFEATURE_FP,
XFEATURE_SSE,
XFEATURE_YMM,
XFEATURE_BNDREGS,
XFEATURE_BNDCSR,
XFEATURE_OPMASK,
XFEATURE_ZMM_Hi256,
XFEATURE_Hi16_ZMM,
XFEATURE_PT_UNIMPLEMENTED_SO_FAR,
XFEATURE_PKRU,
XFEATURE_PASID,
XFEATURE_CET_USER,
XFEATURE_CET_KERNEL_UNUSED,
XFEATURE_RSRVD_COMP_13,
XFEATURE_RSRVD_COMP_14,
XFEATURE_LBR,
XFEATURE_RSRVD_COMP_16,
XFEATURE_XTILECFG,
XFEATURE_XTILEDATA,
XFEATURE_APX,
XFEATURE_MAX,
};
/* Copied from arch/x86/kernel/fpu/xstate.c */
static const char *xfeature_names[] =
{
"x87 floating point registers",
"SSE registers",
"AVX registers",
"MPX bounds registers",
"MPX CSR",
"AVX-512 opmask",
"AVX-512 Hi256",
"AVX-512 ZMM_Hi256",
"Processor Trace (unused)",
"Protection Keys User registers",
"PASID state",
"Control-flow User registers",
"Control-flow Kernel registers (unused)",
"unknown xstate feature",
"unknown xstate feature",
"unknown xstate feature",
"unknown xstate feature",
"AMX Tile config",
"AMX Tile data",
"APX registers",
"unknown xstate feature",
};
struct xsave_buffer {
union {
struct {
char legacy[XSAVE_HDR_OFFSET];
char header[XSAVE_HDR_SIZE];
char extended[0];
};
char bytes[0];
};
};
static inline void xsave(struct xsave_buffer *xbuf, uint64_t rfbm)
{
uint32_t rfbm_hi = rfbm >> 32;
uint32_t rfbm_lo = rfbm;
asm volatile("xsave (%%rdi)"
: : "D" (xbuf), "a" (rfbm_lo), "d" (rfbm_hi)
: "memory");
}
static inline void xrstor(struct xsave_buffer *xbuf, uint64_t rfbm)
{
uint32_t rfbm_hi = rfbm >> 32;
uint32_t rfbm_lo = rfbm;
asm volatile("xrstor (%%rdi)"
: : "D" (xbuf), "a" (rfbm_lo), "d" (rfbm_hi));
}
#define CPUID_LEAF_XSTATE 0xd
#define CPUID_SUBLEAF_XSTATE_USER 0x0
static inline uint32_t get_xbuf_size(void)
{
uint32_t eax, ebx, ecx, edx;
__cpuid_count(CPUID_LEAF_XSTATE, CPUID_SUBLEAF_XSTATE_USER,
eax, ebx, ecx, edx);
/*
* EBX enumerates the size (in bytes) required by the XSAVE
* instruction for an XSAVE area containing all the user state
* components corresponding to bits currently set in XCR0.
*/
return ebx;
}
struct xstate_info {
const char *name;
uint32_t num;
uint32_t mask;
uint32_t xbuf_offset;
uint32_t size;
};
static inline struct xstate_info get_xstate_info(uint32_t xfeature_num)
{
struct xstate_info xstate = { };
uint32_t eax, ebx, ecx, edx;
if (xfeature_num >= XFEATURE_MAX) {
ksft_print_msg("unknown state\n");
return xstate;
}
xstate.name = xfeature_names[xfeature_num];
xstate.num = xfeature_num;
xstate.mask = 1 << xfeature_num;
__cpuid_count(CPUID_LEAF_XSTATE, xfeature_num,
eax, ebx, ecx, edx);
xstate.size = eax;
xstate.xbuf_offset = ebx;
return xstate;
}
static inline struct xsave_buffer *alloc_xbuf(void)
{
uint32_t xbuf_size = get_xbuf_size();
/* XSAVE buffer should be 64B-aligned. */
return aligned_alloc(64, xbuf_size);
}
static inline void clear_xstate_header(struct xsave_buffer *xbuf)
{
memset(&xbuf->header, 0, sizeof(xbuf->header));
}
static inline void set_xstatebv(struct xsave_buffer *xbuf, uint64_t bv)
{
/* XSTATE_BV is at the beginning of the header: */
*(uint64_t *)(&xbuf->header) = bv;
}
/* See 'struct _fpx_sw_bytes' at sigcontext.h */
#define SW_BYTES_OFFSET 464
/* N.B. The struct's field name varies so read from the offset. */
#define SW_BYTES_BV_OFFSET (SW_BYTES_OFFSET + 8)
static inline struct _fpx_sw_bytes *get_fpx_sw_bytes(void *xbuf)
{
return xbuf + SW_BYTES_OFFSET;
}
static inline uint64_t get_fpx_sw_bytes_features(void *buffer)
{
return *(uint64_t *)(buffer + SW_BYTES_BV_OFFSET);
}
static inline void set_rand_data(struct xstate_info *xstate, struct xsave_buffer *xbuf)
{
int *ptr = (int *)&xbuf->bytes[xstate->xbuf_offset];
int data, i;
/*
* Ensure that 'data' is never 0. This ensures that
* the registers are never in their initial configuration
* and thus never tracked as being in the init state.
*/
data = rand() | 1;
for (i = 0; i < xstate->size / sizeof(int); i++, ptr++)
*ptr = data;
}
/* Testing kernel's context switching and ABI support for the xstate. */
void test_xstate(uint32_t feature_num);
#endif /* __SELFTESTS_X86_XSTATE_H */
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