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Commit e03b644f authored by Gleb Natapov's avatar Gleb Natapov Committed by Avi Kivity
Browse files

KVM: introduce kvm_read_guest_cached 



Introduce kvm_read_guest_cached() function in addition to write one we
already have.

[ by glauber: export function signature in kvm header ]

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarGlauber Costa <glommer@redhat.com>
Acked-by: default avatarRik van Riel <riel@redhat.com>
Tested-by: default avatarEric Munson <emunson@mgebm.net>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 29d03158

include/linux/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -381,6 +381,8 @@ int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, 
int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,

			  unsigned long len);

int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len);

int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,

			   void *data, unsigned long len);

int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,

			 int offset, int len);

int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,

virt/kvm/kvm_main.c

+20 −0
Original line number Diff line number Diff line
@@ -1418,6 +1418,26 @@ int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, 
}

EXPORT_SYMBOL_GPL(kvm_write_guest_cached);



int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,

			   void *data, unsigned long len)

{

	struct kvm_memslots *slots = kvm_memslots(kvm);

	int r;



	if (slots->generation != ghc->generation)

		kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);



	if (kvm_is_error_hva(ghc->hva))

		return -EFAULT;



	r = __copy_from_user(data, (void __user *)ghc->hva, len);

	if (r)

		return -EFAULT;



	return 0;

}

EXPORT_SYMBOL_GPL(kvm_read_guest_cached);



int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)

{

	return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page,