diff options
Diffstat (limited to 'arch/arm64/include/asm/kvm_mmu.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index b98ac6aa631f..ae563ebd6aee 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -371,6 +371,24 @@ static inline void kvm_fault_unlock(struct kvm *kvm) read_unlock(&kvm->mmu_lock); } +/* + * ARM64 KVM relies on a simple conversion from physaddr to a kernel + * virtual address (KVA) when it does cache maintenance as the CMO + * instructions work on virtual addresses. This is incompatible with + * VM_PFNMAP VMAs which may not have a kernel direct mapping to a + * virtual address. + * + * With S2FWB and CACHE DIC features, KVM need not do cache flushing + * and CMOs are NOP'd. This has the effect of no longer requiring a + * KVA for addresses mapped into the S2. The presence of these features + * are thus necessary to support cacheable S2 mapping of VM_PFNMAP. + */ +static inline bool kvm_supports_cacheable_pfnmap(void) +{ + return cpus_have_final_cap(ARM64_HAS_STAGE2_FWB) && + cpus_have_final_cap(ARM64_HAS_CACHE_DIC); +} + #ifdef CONFIG_PTDUMP_STAGE2_DEBUGFS void kvm_s2_ptdump_create_debugfs(struct kvm *kvm); #else |