diff options
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 7a65e57b9b41..52664c3caaab 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -6125,14 +6125,15 @@ static int topup_split_caches(struct kvm *kvm) { /* * Allocating rmap list entries when splitting huge pages for nested - * MMUs is uncommon as KVM needs to allocate if and only if there is + * MMUs is uncommon as KVM needs to use a list if and only if there is * more than one rmap entry for a gfn, i.e. requires an L1 gfn to be - * aliased by multiple L2 gfns. Aliasing gfns when using TDP is very - * atypical for VMMs; a few gfns are often aliased during boot, e.g. - * when remapping firmware, but aliasing rarely occurs post-boot). If - * there is only one rmap entry, rmap->val points directly at that one - * entry and doesn't need to allocate a list. Buffer the cache by the - * default capacity so that KVM doesn't have to topup the cache if it + * aliased by multiple L2 gfns and/or from multiple nested roots with + * different roles. Aliasing gfns when using TDP is atypical for VMMs; + * a few gfns are often aliased during boot, e.g. when remapping BIOS, + * but aliasing rarely occurs post-boot or for many gfns. If there is + * only one rmap entry, rmap->val points directly at that one entry and + * doesn't need to allocate a list. Buffer the cache by the default + * capacity so that KVM doesn't have to drop mmu_lock to topup if KVM * encounters an aliased gfn or two. */ const int capacity = SPLIT_DESC_CACHE_MIN_NR_OBJECTS + |