[PATCH] x86-64: Add EFER to the register set saved by save_processor_state

EFER varies like %cr4 depending on the cpu capabilities, and which cpu
capabilities we want to make use of.  So save/restore it make certain
we have the same EFER value when we are done.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Vivek Goyal 2007-05-02 19:27:07 +02:00 committed by Andi Kleen
parent 30f4728954
commit 3c321bceb4
2 changed files with 3 additions and 1 deletions

View File

@ -33,7 +33,6 @@ void __save_processor_state(struct saved_context *ctxt)
asm volatile ("str %0" : "=m" (ctxt->tr));
/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
/* EFER should be constant for kernel version, no need to handle it. */
/*
* segment registers
*/
@ -50,6 +49,7 @@ void __save_processor_state(struct saved_context *ctxt)
/*
* control registers
*/
rdmsrl(MSR_EFER, ctxt->efer);
asm volatile ("movq %%cr0, %0" : "=r" (ctxt->cr0));
asm volatile ("movq %%cr2, %0" : "=r" (ctxt->cr2));
asm volatile ("movq %%cr3, %0" : "=r" (ctxt->cr3));
@ -75,6 +75,7 @@ void __restore_processor_state(struct saved_context *ctxt)
/*
* control registers
*/
wrmsrl(MSR_EFER, ctxt->efer);
asm volatile ("movq %0, %%cr8" :: "r" (ctxt->cr8));
asm volatile ("movq %0, %%cr4" :: "r" (ctxt->cr4));
asm volatile ("movq %0, %%cr3" :: "r" (ctxt->cr3));

View File

@ -17,6 +17,7 @@ struct saved_context {
u16 ds, es, fs, gs, ss;
unsigned long gs_base, gs_kernel_base, fs_base;
unsigned long cr0, cr2, cr3, cr4, cr8;
unsigned long efer;
u16 gdt_pad;
u16 gdt_limit;
unsigned long gdt_base;