diff options
Diffstat (limited to 'arch/x86/mm/init.c')
| -rw-r--r-- | arch/x86/mm/init.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 7777ccc0e9f9..af5c1ed21d43 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -19,6 +19,7 @@ #include <asm/microcode.h> #include <asm/kaslr.h> #include <asm/hypervisor.h> +#include <asm/cpufeature.h> /* * We need to define the tracepoints somewhere, and tlb.c @@ -193,6 +194,38 @@ static void __init probe_page_size_mask(void) } } +static void setup_pcid(void) +{ +#ifdef CONFIG_X86_64 + if (boot_cpu_has(X86_FEATURE_PCID)) { + if (boot_cpu_has(X86_FEATURE_PGE)) { + /* + * This can't be cr4_set_bits_and_update_boot() -- + * the trampoline code can't handle CR4.PCIDE and + * it wouldn't do any good anyway. Despite the name, + * cr4_set_bits_and_update_boot() doesn't actually + * cause the bits in question to remain set all the + * way through the secondary boot asm. + * + * Instead, we brute-force it and set CR4.PCIDE + * manually in start_secondary(). + */ + cr4_set_bits(X86_CR4_PCIDE); + } else { + /* + * flush_tlb_all(), as currently implemented, won't + * work if PCID is on but PGE is not. Since that + * combination doesn't exist on real hardware, there's + * no reason to try to fully support it, but it's + * polite to avoid corrupting data if we're on + * an improperly configured VM. + */ + setup_clear_cpu_cap(X86_FEATURE_PCID); + } + } +#endif +} + #ifdef CONFIG_X86_32 #define NR_RANGE_MR 3 #else /* CONFIG_X86_64 */ @@ -592,6 +625,7 @@ void __init init_mem_mapping(void) unsigned long end; probe_page_size_mask(); + setup_pcid(); #ifdef CONFIG_X86_64 end = max_pfn << PAGE_SHIFT; |