freebsd-nq/sys/amd64/vmm/amd/svm_genassym.c
Neel Natu 30571674ce Simplify register state save and restore across a VMRUN:
- Host registers are now stored on the stack instead of a per-cpu host context.

- Host %FS and %GS selectors are not saved and restored across VMRUN.
  - Restoring the %FS/%GS selectors was futile anyways since that only updates
    the low 32 bits of base address in the hidden descriptor state.
  - GS.base is properly updated via the MSR_GSBASE on return from svm_launch().
  - FS.base is not used while inside the kernel so it can be safely ignored.

- Add function prologue/epilogue so svm_launch() can be traced with Dtrace's
  FBT entry/exit probes. They also serve to save/restore the host %rbp across
  VMRUN.

Reviewed by:	grehan
Discussed with:	Anish Gupta (akgupt3@gmail.com)
2014-09-27 02:04:58 +00:00

49 lines
2.2 KiB
C

/*-
* Copyright (c) 2013 Anish Gupta (akgupt3@gmail.com)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/assym.h>
#include "svm.h"
ASSYM(SCTX_RBX, offsetof(struct svm_regctx, sctx_rbx));
ASSYM(SCTX_RCX, offsetof(struct svm_regctx, sctx_rcx));
ASSYM(SCTX_RBP, offsetof(struct svm_regctx, sctx_rbp));
ASSYM(SCTX_RDX, offsetof(struct svm_regctx, sctx_rdx));
ASSYM(SCTX_RDI, offsetof(struct svm_regctx, sctx_rdi));
ASSYM(SCTX_RSI, offsetof(struct svm_regctx, sctx_rsi));
ASSYM(SCTX_R8, offsetof(struct svm_regctx, sctx_r8));
ASSYM(SCTX_R9, offsetof(struct svm_regctx, sctx_r9));
ASSYM(SCTX_R10, offsetof(struct svm_regctx, sctx_r10));
ASSYM(SCTX_R11, offsetof(struct svm_regctx, sctx_r11));
ASSYM(SCTX_R12, offsetof(struct svm_regctx, sctx_r12));
ASSYM(SCTX_R13, offsetof(struct svm_regctx, sctx_r13));
ASSYM(SCTX_R14, offsetof(struct svm_regctx, sctx_r14));
ASSYM(SCTX_R15, offsetof(struct svm_regctx, sctx_r15));