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| author | Keir Fraser <keir@xen.org> | 2011-01-21 15:58:27 +0000 |
|---|---|---|
| committer | Keir Fraser <keir@xen.org> | 2011-01-21 15:58:27 +0000 |
| commit | 4b00b9efae1190d759e1f4e01e1af2e3767b575c (patch) | |
| tree | 7288fd1c6970581861b164baf3e5746c865d56e2 | |
| parent | f2154f99137f7021e76d2f5ad7e3155ff29fafde (diff) | |
| download | xen-4b00b9efae1190d759e1f4e01e1af2e3767b575c.tar.gz xen-4b00b9efae1190d759e1f4e01e1af2e3767b575c.tar.bz2 xen-4b00b9efae1190d759e1f4e01e1af2e3767b575c.zip | |
x86:x2apic: Disable x2apic on x86-32 permanently
x2apic initialization on x86_32 uses vcpu pointer before it is
initialized. As x2apic is unlikely to be used on x86_32, this patch
disables x2apic permanently on x86_32. It also asserts the sanity of
vcpu pointer before dereference to prevent further misuse.
Signed-off-by: Fengzhe Zhang <fengzhe.zhang@intel.com>
| -rw-r--r-- | xen/arch/x86/apic.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/xen/arch/x86/apic.c b/xen/arch/x86/apic.c index 1590c3a171..ceefc6784d 100644 --- a/xen/arch/x86/apic.c +++ b/xen/arch/x86/apic.c @@ -961,6 +961,22 @@ void __init x2apic_bsp_setup(void) if ( !cpu_has_x2apic ) return; +#ifdef __i386__ + clear_bit(X86_FEATURE_X2APIC, boot_cpu_data.x86_capability); + if ( x2apic_enabled ) + { + uint64_t msr_content; + rdmsrl(MSR_IA32_APICBASE, msr_content); + msr_content &= ~(MSR_IA32_APICBASE_ENABLE | MSR_IA32_APICBASE_EXTD); + wrmsrl(MSR_IA32_APICBASE, msr_content); + msr_content |= MSR_IA32_APICBASE_ENABLE; + wrmsrl(MSR_IA32_APICBASE, msr_content); + x2apic_enabled = 0; + } + printk("x2APIC disabled permanently on x86_32.\n"); + return; +#endif + if ( !opt_x2apic ) { if ( !x2apic_enabled ) |