diff options
Diffstat (limited to 'arch/powerpc/mm/tlb-radix.c')
| -rw-r--r-- | arch/powerpc/mm/tlb-radix.c | 45 |
1 files changed, 43 insertions, 2 deletions
diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c index 744e0164ecf5..16ae1bbe13f0 100644 --- a/arch/powerpc/mm/tlb-radix.c +++ b/arch/powerpc/mm/tlb-radix.c @@ -12,12 +12,12 @@ #include <linux/mm.h> #include <linux/hugetlb.h> #include <linux/memblock.h> -#include <asm/ppc-opcode.h> +#include <asm/ppc-opcode.h> #include <asm/tlb.h> #include <asm/tlbflush.h> #include <asm/trace.h> - +#include <asm/cputhreads.h> #define RIC_FLUSH_TLB 0 #define RIC_FLUSH_PWC 1 @@ -454,3 +454,44 @@ void radix__flush_tlb_pte_p9_dd1(unsigned long old_pte, struct mm_struct *mm, else radix__flush_tlb_page_psize(mm, address, mmu_virtual_psize); } + +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE +extern void radix_kvm_prefetch_workaround(struct mm_struct *mm) +{ + unsigned int pid = mm->context.id; + + if (unlikely(pid == MMU_NO_CONTEXT)) + return; + + /* + * If this context hasn't run on that CPU before and KVM is + * around, there's a slim chance that the guest on another + * CPU just brought in obsolete translation into the TLB of + * this CPU due to a bad prefetch using the guest PID on + * the way into the hypervisor. + * + * We work around this here. If KVM is possible, we check if + * any sibling thread is in KVM. If it is, the window may exist + * and thus we flush that PID from the core. + * + * A potential future improvement would be to mark which PIDs + * have never been used on the system and avoid it if the PID + * is new and the process has no other cpumask bit set. + */ + if (cpu_has_feature(CPU_FTR_HVMODE) && radix_enabled()) { + int cpu = smp_processor_id(); + int sib = cpu_first_thread_sibling(cpu); + bool flush = false; + + for (; sib <= cpu_last_thread_sibling(cpu) && !flush; sib++) { + if (sib == cpu) + continue; + if (paca[sib].kvm_hstate.kvm_vcpu) + flush = true; + } + if (flush) + _tlbiel_pid(pid, RIC_FLUSH_ALL); + } +} +EXPORT_SYMBOL_GPL(radix_kvm_prefetch_workaround); +#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */ |