diff options
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 51 |
1 files changed, 41 insertions, 10 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 475a100f3a2..2803b4db2a3 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -959,7 +959,7 @@ static pfn_t get_fault_pfn(void) } static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, - bool *async) + bool *async, bool write_fault, bool *writable) { struct page *page[1]; int npages = 0; @@ -968,12 +968,34 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, /* we can do it either atomically or asynchronously, not both */ BUG_ON(atomic && async); + BUG_ON(!write_fault && !writable); + + if (writable) + *writable = true; + if (atomic || async) npages = __get_user_pages_fast(addr, 1, 1, page); if (unlikely(npages != 1) && !atomic) { might_sleep(); - npages = get_user_pages_fast(addr, 1, 1, page); + + if (writable) + *writable = write_fault; + + npages = get_user_pages_fast(addr, 1, write_fault, page); + + /* map read fault as writable if possible */ + if (unlikely(!write_fault) && npages == 1) { + struct page *wpage[1]; + + npages = __get_user_pages_fast(addr, 1, 1, wpage); + if (npages == 1) { + *writable = true; + put_page(page[0]); + page[0] = wpage[0]; + } + npages = 1; + } } if (unlikely(npages != 1)) { @@ -1011,11 +1033,12 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr) { - return hva_to_pfn(kvm, addr, true, NULL); + return hva_to_pfn(kvm, addr, true, NULL, true, NULL); } EXPORT_SYMBOL_GPL(hva_to_pfn_atomic); -static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async) +static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async, + bool write_fault, bool *writable) { unsigned long addr; @@ -1028,32 +1051,40 @@ static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async) return page_to_pfn(bad_page); } - return hva_to_pfn(kvm, addr, atomic, async); + return hva_to_pfn(kvm, addr, atomic, async, write_fault, writable); } pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn) { - return __gfn_to_pfn(kvm, gfn, true, NULL); + return __gfn_to_pfn(kvm, gfn, true, NULL, true, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic); -pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async) +pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async, + bool write_fault, bool *writable) { - return __gfn_to_pfn(kvm, gfn, false, async); + return __gfn_to_pfn(kvm, gfn, false, async, write_fault, writable); } EXPORT_SYMBOL_GPL(gfn_to_pfn_async); pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) { - return __gfn_to_pfn(kvm, gfn, false, NULL); + return __gfn_to_pfn(kvm, gfn, false, NULL, true, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn); +pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, + bool *writable) +{ + return __gfn_to_pfn(kvm, gfn, false, NULL, write_fault, writable); +} +EXPORT_SYMBOL_GPL(gfn_to_pfn_prot); + pfn_t gfn_to_pfn_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn) { unsigned long addr = gfn_to_hva_memslot(slot, gfn); - return hva_to_pfn(kvm, addr, false, NULL); + return hva_to_pfn(kvm, addr, false, NULL, true, NULL); } int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages, |