corda/psw/urts/urts_xsave.cpp
Angie Chinchilla 9441de4c38 Initial release of Intel SGX for Linux.
This release is used in conjunction with the linux-sgx-driver Intial release:
https://github.com/01org/linux-sgx-driver
commit-id: 0e865ce5e6b297a787bcdc12d98bada8174be6d7

Intel-id: 33399

Signed-off-by: Angie Chinchilla <angie.v.chinchilla@intel.com>
2016-06-23 18:51:53 -04:00

92 lines
2.8 KiB
C++

/*
* Copyright (C) 2011-2016 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "xsave.h"
#include "util.h"
#include "se_detect.h"
#include "sgx_attributes.h"
#define XFRM_YMM_BITMASK 0x00000004
// save_and_clean_xfeature_regs()
// do fwait, fxsave, and then clear the upper bits of YMM regs before executing EENTER.
// Parameters:
// buffer - if the pointer is not NULL, save the CPU state to the buffer
// Return Value:
// none
void save_and_clean_xfeature_regs(uint8_t *buffer)
{
// XCR0 is not supposed to be changed. So query it once.
static uint64_t xcr0 = 0;
if(xcr0 == 0)
{
if(false == try_read_xcr0(&xcr0))
{
xcr0 = SGX_XFRM_LEGACY;
}
}
// do fwait to flush the float-point exceptions
do_fwait();
// do fxsave to save the CPU state before ecall
// no need to save the CPU state before oret
if(buffer != 0)
{
uint8_t *buf = (uint8_t*)ROUND_TO((size_t)buffer, FXSAVE_ALIGN_SIZE);
do_fxsave(buf);
}
// clean the upper bits of the YMM regs
if(xcr0 & XFRM_YMM_BITMASK)
{
do_vzeroupper();
}
}
void restore_xfeature_regs(const uint8_t *buffer)
{
if (buffer)
{
uint8_t *buf = (uint8_t*)ROUND_TO((size_t)buffer, FXSAVE_ALIGN_SIZE);
do_fxrstor(buf);
}
}