Commit 0958f0ce authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
Browse files

KVM: introduce kvm_read_guest_offset_cached() 



We already have kvm_write_guest_offset_cached(), introduce read analogue.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200525144125.143875-5-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 7c0ade6c

include/linux/kvm_host.h

+3 −0
Original line number Diff line number Diff line
@@ -734,6 +734,9 @@ int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, 
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_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,

				 void *data, unsigned int offset,

				 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

+14 −5
Original line number Diff line number Diff line
@@ -2510,13 +2510,15 @@ 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)

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

				 void *data, unsigned int offset,

				 unsigned long len)

{

	struct kvm_memslots *slots = kvm_memslots(kvm);

	int r;

	gpa_t gpa = ghc->gpa + offset;



	BUG_ON(len > ghc->len);

	BUG_ON(len + offset > ghc->len);



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

		if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
@@ -2527,14 +2529,21 @@ int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, 
		return -EFAULT;



	if (unlikely(!ghc->memslot))

		return kvm_read_guest(kvm, ghc->gpa, data, len);

		return kvm_read_guest(kvm, gpa, data, len);



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

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

	if (r)

		return -EFAULT;



	return 0;

}

EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached);



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

			  void *data, unsigned long len)

{

	return kvm_read_guest_offset_cached(kvm, ghc, data, 0, len);

}

EXPORT_SYMBOL_GPL(kvm_read_guest_cached);



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

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