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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: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Xiao Guangrong 2010-08-22 19:10:28 +08:00 committed by Avi Kivity
parent 45888a0c6e
commit 887c08ac19
2 changed files with 26 additions and 11 deletions
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7
include/linux/kvm_host.h
View File

@ -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;

30
virt/kvm/kvm_main.c
View File

@ -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;
might_sleep();
npages = get_user_pages_fast(addr, 1, 1, page);
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)