static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
{
int ret;
ret = 0;
switch (msr) {
#ifdef CONFIG_X86_64
unsigned which;
u64 base;
case MSR_FS_BASE:
which = SEGBASE_FS;
goto set;
case MSR_KERNEL_GS_BASE:
which = SEGBASE_GS_USER;
goto set;
case MSR_GS_BASE:
which = SEGBASE_GS_KERNEL;
goto set;
set:
base = ((u64)high << 32) | low;
if (HYPERVISOR_set_segment_base(which, base) != 0)
ret = -EIO;
break;
#endif
case MSR_STAR:
case MSR_CSTAR:
case MSR_LSTAR:
case MSR_SYSCALL_MASK:
case MSR_IA32_SYSENTER_CS:
case MSR_IA32_SYSENTER_ESP:
case MSR_IA32_SYSENTER_EIP:
/* Fast syscall setup is all done in hypercalls, so
these are all ignored. Stub them out here to stop
Xen console noise. */
break;
default:
ret = native_write_msr_safe(msr, low, high);
}
return ret;
}
static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
{
int ret;
ret = 0;
switch (msr) {
#ifdef CONFIG_X86_64
unsigned which;
u64 base;
case MSR_FS_BASE: which = SEGBASE_FS; goto set;
case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
set:
base = ((u64)high << 32) | low;
if (HYPERVISOR_set_segment_base(which, base) != 0)
ret = -EIO;
break;
#endif
case MSR_STAR:
case MSR_CSTAR:
case MSR_LSTAR:
case MSR_SYSCALL_MASK:
case MSR_IA32_SYSENTER_CS:
case MSR_IA32_SYSENTER_ESP:
case MSR_IA32_SYSENTER_EIP:
/*
*/
break;
case MSR_IA32_CR_PAT:
if (smp_processor_id() == 0)
xen_set_pat(((u64)high << 32) | low);
break;
default:
ret = native_write_msr_safe(msr, low, high);
}
return ret;
}