Commit 48987781 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
Browse files

KVM: MMU: introduce gfn_to_page_many_atomic() function 



Introduce this function to get consecutive gfn's pages, it can reduce
gup's overload, used by later patch

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 887c08ac

include/linux/kvm_host.h

+3 −0
Original line number Diff line number Diff line
@@ -289,6 +289,9 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, 
void kvm_disable_largepages(void);

void kvm_arch_flush_shadow(struct kvm *kvm);



int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,

			    int nr_pages);



struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);

unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn);

void kvm_release_page_clean(struct page *page);

virt/kvm/kvm_main.c

+28 −1
Original line number Diff line number Diff line
@@ -927,15 +927,25 @@ int memslot_id(struct kvm *kvm, gfn_t gfn) 
	return memslot - slots->memslots;

}



unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)

static unsigned long gfn_to_hva_many(struct kvm *kvm, gfn_t gfn,

				     gfn_t *nr_pages)

{

	struct kvm_memory_slot *slot;



	slot = gfn_to_memslot(kvm, gfn);

	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)

		return bad_hva();



	if (nr_pages)

		*nr_pages = slot->npages - (gfn - slot->base_gfn);



	return gfn_to_hva_memslot(slot, gfn);

}



unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)

{

	return gfn_to_hva_many(kvm, gfn, NULL);

}

EXPORT_SYMBOL_GPL(gfn_to_hva);



static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic)
@@ -1010,6 +1020,23 @@ pfn_t gfn_to_pfn_memslot(struct kvm *kvm, 
	return hva_to_pfn(kvm, addr, false);

}



int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,

								  int nr_pages)

{

	unsigned long addr;

	gfn_t entry;



	addr = gfn_to_hva_many(kvm, gfn, &entry);

	if (kvm_is_error_hva(addr))

		return -1;



	if (entry < nr_pages)

		return 0;



	return __get_user_pages_fast(addr, nr_pages, 1, pages);

}

EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);



struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)

{

	pfn_t pfn;