Commit 887c08ac authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
Browse files

KVM: MMU: introduce hva_to_pfn_atomic function 



Introduce hva_to_pfn_atomic(), it's the fast path and can used in atomic
context, the later patch will use it

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 45888a0c

include/linux/kvm_host.h

+7 −0
Original line number Diff line number Diff line
@@ -296,6 +296,7 @@ void kvm_release_page_dirty(struct page *page); 
void kvm_set_page_dirty(struct page *page);

void kvm_set_page_accessed(struct page *page);



pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr);

pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);

pfn_t gfn_to_pfn_memslot(struct kvm *kvm,

			 struct kvm_memory_slot *slot, gfn_t gfn);
@@ -518,6 +519,12 @@ static inline void kvm_guest_exit(void) 
	current->flags &= ~PF_VCPU;

}



static inline unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,

					       gfn_t gfn)

{

	return slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE;

}



static inline gpa_t gfn_to_gpa(gfn_t gfn)

{

	return (gpa_t)gfn << PAGE_SHIFT;

virt/kvm/kvm_main.c

+19 −11
Original line number Diff line number Diff line
@@ -927,11 +927,6 @@ int memslot_id(struct kvm *kvm, gfn_t gfn) 
	return memslot - slots->memslots;

}



static unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn)

{

	return slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE;

}



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

{

	struct kvm_memory_slot *slot;
@@ -943,19 +938,25 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) 
}

EXPORT_SYMBOL_GPL(gfn_to_hva);



static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)

static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic)

{

	struct page *page[1];

	int npages;

	pfn_t pfn;



	if (atomic)

		npages = __get_user_pages_fast(addr, 1, 1, page);

	else {

		might_sleep();



		npages = get_user_pages_fast(addr, 1, 1, page);

	}



	if (unlikely(npages != 1)) {

		struct vm_area_struct *vma;



		if (atomic)

			goto return_fault_page;



		down_read(&current->mm->mmap_sem);

		if (is_hwpoison_address(addr)) {

			up_read(&current->mm->mmap_sem);
@@ -968,6 +969,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr) 
		if (vma == NULL || addr < vma->vm_start ||

		    !(vma->vm_flags & VM_PFNMAP)) {

			up_read(&current->mm->mmap_sem);

return_fault_page:

			get_page(fault_page);

			return page_to_pfn(fault_page);

		}
@@ -981,6 +983,12 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr) 
	return pfn;

}



pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr)

{

	return hva_to_pfn(kvm, addr, true);

}

EXPORT_SYMBOL_GPL(hva_to_pfn_atomic);



pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)

{

	unsigned long addr;
@@ -991,7 +999,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) 
		return page_to_pfn(bad_page);

	}



	return hva_to_pfn(kvm, addr);

	return hva_to_pfn(kvm, addr, false);

}

EXPORT_SYMBOL_GPL(gfn_to_pfn);
@@ -999,7 +1007,7 @@ pfn_t gfn_to_pfn_memslot(struct kvm *kvm, 
			 struct kvm_memory_slot *slot, gfn_t gfn)

{

	unsigned long addr = gfn_to_hva_memslot(slot, gfn);

	return hva_to_pfn(kvm, addr);

	return hva_to_pfn(kvm, addr, false);

}



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