KVM: Add kvm_read_guest_atomic()

In preparation for a mmu spinlock, add kvm_read_guest_atomic()
and use it in fetch() and prefetch_page().

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Marcelo Tosatti
2007-12-20 19:18:23 -05:00
committed by Avi Kivity
parent 10589a4699
commit 7ec5458821
3 changed files with 38 additions and 12 deletions

View File

@@ -541,6 +541,26 @@ int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
}
EXPORT_SYMBOL_GPL(kvm_read_guest);
int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
unsigned long len)
{
int r;
unsigned long addr;
gfn_t gfn = gpa >> PAGE_SHIFT;
int offset = offset_in_page(gpa);
addr = gfn_to_hva(kvm, gfn);
if (kvm_is_error_hva(addr))
return -EFAULT;
pagefault_disable();
r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
pagefault_enable();
if (r)
return -EFAULT;
return 0;
}
EXPORT_SYMBOL(kvm_read_guest_atomic);
int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
int offset, int len)
{