mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-11-25 00:12:56 +00:00
86 lines
2.3 KiB
Diff
86 lines
2.3 KiB
Diff
--- a/arch/x86/xen/enlighten.c
|
|
+++ b/arch/x86/xen/enlighten.c
|
|
@@ -168,21 +168,23 @@ static void __init xen_banner(void)
|
|
xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
|
|
}
|
|
|
|
+static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
|
|
+static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
|
|
+
|
|
static void xen_cpuid(unsigned int *ax, unsigned int *bx,
|
|
unsigned int *cx, unsigned int *dx)
|
|
{
|
|
+ unsigned maskecx = ~0;
|
|
unsigned maskedx = ~0;
|
|
|
|
/*
|
|
* Mask out inconvenient features, to try and disable as many
|
|
* unsupported kernel subsystems as possible.
|
|
*/
|
|
- if (*ax == 1)
|
|
- maskedx = ~((1 << X86_FEATURE_APIC) | /* disable APIC */
|
|
- (1 << X86_FEATURE_ACPI) | /* disable ACPI */
|
|
- (1 << X86_FEATURE_MCE) | /* disable MCE */
|
|
- (1 << X86_FEATURE_MCA) | /* disable MCA */
|
|
- (1 << X86_FEATURE_ACC)); /* thermal monitoring */
|
|
+ if (*ax == 1) {
|
|
+ maskecx = cpuid_leaf1_ecx_mask;
|
|
+ maskedx = cpuid_leaf1_edx_mask;
|
|
+ }
|
|
|
|
asm(XEN_EMULATE_PREFIX "cpuid"
|
|
: "=a" (*ax),
|
|
@@ -190,9 +192,43 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
|
|
"=c" (*cx),
|
|
"=d" (*dx)
|
|
: "0" (*ax), "2" (*cx));
|
|
+
|
|
+ *cx &= maskecx;
|
|
*dx &= maskedx;
|
|
}
|
|
|
|
+static __init void xen_init_cpuid_mask(void)
|
|
+{
|
|
+ unsigned int ax, bx, cx, dx;
|
|
+
|
|
+ cpuid_leaf1_edx_mask =
|
|
+ ~((1 << X86_FEATURE_MCE) | /* disable MCE */
|
|
+ (1 << X86_FEATURE_MCA) | /* disable MCA */
|
|
+ (1 << X86_FEATURE_ACC)); /* thermal monitoring */
|
|
+
|
|
+ if (!xen_initial_domain())
|
|
+ cpuid_leaf1_edx_mask &=
|
|
+ ~((1 << X86_FEATURE_APIC) | /* disable local APIC */
|
|
+ (1 << X86_FEATURE_ACPI)); /* disable ACPI */
|
|
+
|
|
+ ax = 1;
|
|
+ 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();
|
|
+
|
|
+ if ((cr4 & X86_CR4_OSXSAVE) == 0)
|
|
+ cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_XSAVE % 32));
|
|
+
|
|
+ clear_in_cr4(X86_CR4_OSXSAVE);
|
|
+ }
|
|
+}
|
|
+
|
|
static void xen_set_debugreg(int reg, unsigned long val)
|
|
{
|
|
HYPERVISOR_set_debugreg(reg, val);
|
|
@@ -903,6 +939,8 @@ asmlinkage void __init xen_start_kernel(void)
|
|
|
|
xen_init_irq_ops();
|
|
|
|
+ xen_init_cpuid_mask();
|
|
+
|
|
#ifdef CONFIG_X86_LOCAL_APIC
|
|
/*
|
|
* set up the basic apic ops.
|