Currently KAISER kills PCID on platforms that lack INVPCID, even when nokaiser. Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> --- arch/x86/include/asm/tlbflush.h | 9 +++++---- arch/x86/mm/init.c | 2 +- arch/x86/mm/tlb.c | 7 ++++++- 3 files changed, 12 insertions(+), 6 deletions(-) --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -9,6 +9,7 @@ #include <asm/cpufeature.h> #include <asm/special_insns.h> #include <asm/smp.h> +#include <asm/kaiser.h> static inline void __invpcid(unsigned long pcid, unsigned long addr, unsigned long type) @@ -355,12 +356,12 @@ static inline void __native_flush_tlb(vo * CR4 has X86_CR4_PCIDE set. In other words, this does * not fully flush the TLB if PCIDs are in use. * - * With KAISER and PCIDs, the means that we did not + * With KAISER and PCIDs, that means that we did not * flush the user PCID. Warn if it gets called. */ - if (IS_ENABLED(CONFIG_KAISER)) - WARN_ON_ONCE(this_cpu_read(cpu_tlbstate.cr4) & - X86_CR4_PCIDE); + if (IS_ENABLED(CONFIG_KAISER) && kaiser_enabled) + WARN_ON_ONCE(this_cpu_read(cpu_tlbstate.cr4) & X86_CR4_PCIDE); + /* * If current->mm == NULL then we borrow a mm * which may change during a task switch and --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -219,7 +219,7 @@ static void setup_pcid(void) * have KAISER and do not have INVPCID. */ if (!IS_ENABLED(CONFIG_X86_GLOBAL_PAGES) && - !boot_cpu_has(X86_FEATURE_INVPCID)) { + kaiser_enabled && !boot_cpu_has(X86_FEATURE_INVPCID)) { setup_clear_cpu_cap(X86_FEATURE_PCID); return; } --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -6,13 +6,14 @@ #include <linux/interrupt.h> #include <linux/export.h> #include <linux/cpu.h> +#include <linux/debugfs.h> #include <asm/tlbflush.h> #include <asm/mmu_context.h> #include <asm/cache.h> #include <asm/apic.h> #include <asm/uv/uv.h> -#include <linux/debugfs.h> +#include <asm/kaiser.h> /* * TLB flushing, formerly SMP-only @@ -115,6 +116,10 @@ static void flush_user_asid(pgd_t *pgd, */ if (!cpu_feature_enabled(X86_FEATURE_PCID)) return; + + if (!kaiser_enabled) + return; + /* * With PCIDs enabled, write_cr3() only flushes TLB * entries for the current (kernel) ASID. This leaves -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>