diff options
| -rw-r--r-- | virt/kvm/kvm_main.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5bbb5612b207..2500178cf444 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2517,7 +2517,18 @@ static bool hva_to_pfn_fast(unsigned long addr, bool write_fault, static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, bool interruptible, bool *writable, kvm_pfn_t *pfn) { - unsigned int flags = FOLL_HWPOISON; + /* + * When a VCPU accesses a page that is not mapped into the secondary + * MMU, we lookup the page using GUP to map it, so the guest VCPU can + * make progress. We always want to honor NUMA hinting faults in that + * case, because GUP usage corresponds to memory accesses from the VCPU. + * Otherwise, we'd not trigger NUMA hinting faults once a page is + * mapped into the secondary MMU and gets accessed by a VCPU. + * + * Note that get_user_page_fast_only() and FOLL_WRITE for now + * implicitly honor NUMA hinting faults and don't need this flag. + */ + unsigned int flags = FOLL_HWPOISON | FOLL_HONOR_NUMA_FAULT; struct page *page; int npages; |