linux_dsm_epyc7002/arch/x86/include/asm/fpu/xstate.h
Yu-cheng Yu eeedf15336 x86/fpu: Introduce copy_supervisor_to_kernel()
The XSAVES instruction takes a mask and saves only the features specified
in that mask.  The kernel normally specifies that all features be saved.

XSAVES also unconditionally uses the "compacted format" which means that
all specified features are saved next to each other in memory.  If a
feature is removed from the mask, all the features after it will "move
up" into earlier locations in the buffer.

Introduce copy_supervisor_to_kernel(), which saves only supervisor states
and then moves those states into the standard location where they are
normally found.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200512145444.15483-9-yu-cheng.yu@intel.com
2020-05-16 11:24:14 +02:00

84 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_X86_XSAVE_H
#define __ASM_X86_XSAVE_H
#include <linux/uaccess.h>
#include <linux/types.h>
#include <asm/processor.h>
#include <asm/user.h>
/* Bit 63 of XCR0 is reserved for future expansion */
#define XFEATURE_MASK_EXTEND (~(XFEATURE_MASK_FPSSE | (1ULL << 63)))
#define XSTATE_CPUID 0x0000000d
#define FXSAVE_SIZE 512
#define XSAVE_HDR_SIZE 64
#define XSAVE_HDR_OFFSET FXSAVE_SIZE
#define XSAVE_YMM_SIZE 256
#define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
/* All currently supported user features */
#define XFEATURE_MASK_USER_SUPPORTED (XFEATURE_MASK_FP | \
XFEATURE_MASK_SSE | \
XFEATURE_MASK_YMM | \
XFEATURE_MASK_OPMASK | \
XFEATURE_MASK_ZMM_Hi256 | \
XFEATURE_MASK_Hi16_ZMM | \
XFEATURE_MASK_PKRU | \
XFEATURE_MASK_BNDREGS | \
XFEATURE_MASK_BNDCSR)
/* All currently supported supervisor features */
#define XFEATURE_MASK_SUPERVISOR_SUPPORTED (0)
/*
* Unsupported supervisor features. When a supervisor feature in this mask is
* supported in the future, move it to the supported supervisor feature mask.
*/
#define XFEATURE_MASK_SUPERVISOR_UNSUPPORTED (XFEATURE_MASK_PT)
/* All supervisor states including supported and unsupported states. */
#define XFEATURE_MASK_SUPERVISOR_ALL (XFEATURE_MASK_SUPERVISOR_SUPPORTED | \
XFEATURE_MASK_SUPERVISOR_UNSUPPORTED)
#ifdef CONFIG_X86_64
#define REX_PREFIX "0x48, "
#else
#define REX_PREFIX
#endif
extern u64 xfeatures_mask_all;
static inline u64 xfeatures_mask_supervisor(void)
{
return xfeatures_mask_all & XFEATURE_MASK_SUPERVISOR_SUPPORTED;
}
static inline u64 xfeatures_mask_user(void)
{
return xfeatures_mask_all & XFEATURE_MASK_USER_SUPPORTED;
}
extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
extern void __init update_regset_xstate_info(unsigned int size,
u64 xstate_mask);
void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr);
const void *get_xsave_field_ptr(int xfeature_nr);
int using_compacted_format(void);
int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset, unsigned int size);
int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset, unsigned int size);
int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf);
int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf);
void copy_supervisor_to_kernel(struct xregs_state *xsave);
/* Validate an xstate header supplied by userspace (ptrace or sigreturn) */
int validate_user_xstate_header(const struct xstate_header *hdr);
#endif