diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/lguest_hcall.h | 1 | ||||
| -rw-r--r-- | arch/x86/lguest/boot.c | 17 |
2 files changed, 7 insertions, 11 deletions
diff --git a/arch/x86/include/asm/lguest_hcall.h b/arch/x86/include/asm/lguest_hcall.h index ef01fef3eebc..6c119cfae218 100644 --- a/arch/x86/include/asm/lguest_hcall.h +++ b/arch/x86/include/asm/lguest_hcall.h @@ -9,7 +9,6 @@ #define LHCALL_FLUSH_TLB 5 #define LHCALL_LOAD_IDT_ENTRY 6 #define LHCALL_SET_STACK 7 -#define LHCALL_TS 8 #define LHCALL_SET_CLOCKEVENT 9 #define LHCALL_HALT 10 #define LHCALL_SET_PMD 13 diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 25da5bc8d83d..d74afcdbc580 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -497,27 +497,24 @@ static void lguest_cpuid(unsigned int *ax, unsigned int *bx, * a whole series of functions like read_cr0() and write_cr0(). * * We start with cr0. cr0 allows you to turn on and off all kinds of basic - * features, but Linux only really cares about one: the horrifically-named Task - * Switched (TS) bit at bit 3 (ie. 8) + * features, but the only cr0 bit that Linux ever used at runtime was the + * horrifically-named Task Switched (TS) bit at bit 3 (ie. 8) * * What does the TS bit do? Well, it causes the CPU to trap (interrupt 7) if * the floating point unit is used. Which allows us to restore FPU state - * lazily after a task switch, and Linux uses that gratefully, but wouldn't a - * name like "FPUTRAP bit" be a little less cryptic? + * lazily after a task switch if we wanted to, but wouldn't a name like + * "FPUTRAP bit" be a little less cryptic? * - * We store cr0 locally because the Host never changes it. The Guest sometimes - * wants to read it and we'd prefer not to bother the Host unnecessarily. + * Fortunately, Linux keeps it simple and doesn't use TS, so we can ignore + * cr0. */ -static unsigned long current_cr0; static void lguest_write_cr0(unsigned long val) { - lazy_hcall1(LHCALL_TS, val & X86_CR0_TS); - current_cr0 = val; } static unsigned long lguest_read_cr0(void) { - return current_cr0; + return 0; } /* |