diff options
| author | Xiao Guangrong | 2012-08-21 10:59:53 +0800 |
|---|---|---|
| committer | Avi Kivity | 2012-08-22 15:08:53 +0300 |
| commit | 86ab8cffb498077e926957f099b064db3751c1de (patch) | |
| tree | 95209c3c8c31eeb52774994d545a035efd444eb0 /virt/kvm | |
| parent | 037d92dc5d4691ae7cf44699c55ca83b1b441992 (diff) | |
KVM: introduce gfn_to_hva_read/kvm_read_hva/kvm_read_hva_atomic
This set of functions is only used to read data from host space, in the
later patch, we will only get a readonly hva in gfn_to_hva_read, and
the function name is a good hint to let gfn_to_hva_read to pair with
kvm_read_hva()/kvm_read_hva_atomic()
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt/kvm')
| -rw-r--r-- | virt/kvm/kvm_main.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 543f9b7e5aa2..6e3ea15397d4 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1002,6 +1002,25 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) } EXPORT_SYMBOL_GPL(gfn_to_hva); +/* + * The hva returned by this function is only allowed to be read. + * It should pair with kvm_read_hva() or kvm_read_hva_atomic(). + */ +static unsigned long gfn_to_hva_read(struct kvm *kvm, gfn_t gfn) +{ + return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL); +} + +static int kvm_read_hva(void *data, void __user *hva, int len) +{ + return __copy_from_user(data, hva, len); +} + +static int kvm_read_hva_atomic(void *data, void __user *hva, int len) +{ + return __copy_from_user_inatomic(data, hva, len); +} + int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int write, struct page **page) { @@ -1274,10 +1293,10 @@ int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, int r; unsigned long addr; - addr = gfn_to_hva(kvm, gfn); + addr = gfn_to_hva_read(kvm, gfn); if (kvm_is_error_hva(addr)) return -EFAULT; - r = __copy_from_user(data, (void __user *)addr + offset, len); + r = kvm_read_hva(data, (void __user *)addr + offset, len); if (r) return -EFAULT; return 0; @@ -1312,11 +1331,11 @@ int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data, gfn_t gfn = gpa >> PAGE_SHIFT; int offset = offset_in_page(gpa); - addr = gfn_to_hva(kvm, gfn); + addr = gfn_to_hva_read(kvm, gfn); if (kvm_is_error_hva(addr)) return -EFAULT; pagefault_disable(); - r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len); + r = kvm_read_hva_atomic(data, (void __user *)addr + offset, len); pagefault_enable(); if (r) return -EFAULT; |