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Diffstat (limited to 'arch/x86/xen/enlighten.c')
-rw-r--r--arch/x86/xen/enlighten.c21
1 files changed, 7 insertions, 14 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 49dbd78ec3c..e3c6a06cf72 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -238,6 +238,7 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
static __init void xen_init_cpuid_mask(void)
{
unsigned int ax, bx, cx, dx;
+ unsigned int xsave_mask;
cpuid_leaf1_edx_mask =
~((1 << X86_FEATURE_MCE) | /* disable MCE */
@@ -249,24 +250,16 @@ static __init void xen_init_cpuid_mask(void)
cpuid_leaf1_edx_mask &=
~((1 << X86_FEATURE_APIC) | /* disable local APIC */
(1 << X86_FEATURE_ACPI)); /* disable ACPI */
-
ax = 1;
- cx = 0;
xen_cpuid(&ax, &bx, &cx, &dx);
- /* cpuid claims we support xsave; try enabling it to see what happens */
- if (cx & (1 << (X86_FEATURE_XSAVE % 32))) {
- unsigned long cr4;
-
- set_in_cr4(X86_CR4_OSXSAVE);
-
- cr4 = read_cr4();
+ xsave_mask =
+ (1 << (X86_FEATURE_XSAVE % 32)) |
+ (1 << (X86_FEATURE_OSXSAVE % 32));
- if ((cr4 & X86_CR4_OSXSAVE) == 0)
- cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_XSAVE % 32));
-
- clear_in_cr4(X86_CR4_OSXSAVE);
- }
+ /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
+ if ((cx & xsave_mask) != xsave_mask)
+ cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
}
static void xen_set_debugreg(int reg, unsigned long val)