KVM: Introduce gfn_to_hva_memslot_prot

To support read-only memory regions on arm and arm64, we have a need to
resolve a gfn to an hva given a pointer to a memslot to avoid looping
through the memslots twice and to reuse the hva error checking of
gfn_to_hva_prot(), add a new gfn_to_hva_memslot_prot() function and
refactor gfn_to_hva_prot() to use this function.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
Christoffer Dall
2014-08-19 12:15:00 +02:00
parent 7b46268d29
commit 64d831269c
2 changed files with 11 additions and 2 deletions

View File

@@ -1076,9 +1076,9 @@ EXPORT_SYMBOL_GPL(gfn_to_hva);
* If writable is set to false, the hva returned by this function is only
* allowed to be read.
*/
unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot,
gfn_t gfn, bool *writable)
{
struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false);
if (!kvm_is_error_hva(hva) && writable)
@@ -1087,6 +1087,13 @@ unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
return hva;
}
unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
{
struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
return gfn_to_hva_memslot_prot(slot, gfn, writable);
}
static int kvm_read_hva(void *data, void __user *hva, int len)
{
return __copy_from_user(data, hva, len);