KVM: Handle vma regions with no backing page
This patch allows VMAs that contain no backing page to be used for guest memory. This is useful for assigning mmio regions to a guest. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
parent
d2ebb4103f
commit
2e2e3738af
1 changed files with 37 additions and 12 deletions
|
@ -532,6 +532,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
|
||||||
struct page *page[1];
|
struct page *page[1];
|
||||||
unsigned long addr;
|
unsigned long addr;
|
||||||
int npages;
|
int npages;
|
||||||
|
pfn_t pfn;
|
||||||
|
|
||||||
might_sleep();
|
might_sleep();
|
||||||
|
|
||||||
|
@ -544,19 +545,38 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
|
||||||
npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page,
|
npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page,
|
||||||
NULL);
|
NULL);
|
||||||
|
|
||||||
if (npages != 1) {
|
if (unlikely(npages != 1)) {
|
||||||
get_page(bad_page);
|
struct vm_area_struct *vma;
|
||||||
return page_to_pfn(bad_page);
|
|
||||||
}
|
|
||||||
|
|
||||||
return page_to_pfn(page[0]);
|
vma = find_vma(current->mm, addr);
|
||||||
|
if (vma == NULL || addr < vma->vm_start ||
|
||||||
|
!(vma->vm_flags & VM_PFNMAP)) {
|
||||||
|
get_page(bad_page);
|
||||||
|
return page_to_pfn(bad_page);
|
||||||
|
}
|
||||||
|
|
||||||
|
pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
|
||||||
|
BUG_ON(pfn_valid(pfn));
|
||||||
|
} else
|
||||||
|
pfn = page_to_pfn(page[0]);
|
||||||
|
|
||||||
|
return pfn;
|
||||||
}
|
}
|
||||||
|
|
||||||
EXPORT_SYMBOL_GPL(gfn_to_pfn);
|
EXPORT_SYMBOL_GPL(gfn_to_pfn);
|
||||||
|
|
||||||
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
|
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
|
||||||
{
|
{
|
||||||
return pfn_to_page(gfn_to_pfn(kvm, gfn));
|
pfn_t pfn;
|
||||||
|
|
||||||
|
pfn = gfn_to_pfn(kvm, gfn);
|
||||||
|
if (pfn_valid(pfn))
|
||||||
|
return pfn_to_page(pfn);
|
||||||
|
|
||||||
|
WARN_ON(!pfn_valid(pfn));
|
||||||
|
|
||||||
|
get_page(bad_page);
|
||||||
|
return bad_page;
|
||||||
}
|
}
|
||||||
|
|
||||||
EXPORT_SYMBOL_GPL(gfn_to_page);
|
EXPORT_SYMBOL_GPL(gfn_to_page);
|
||||||
|
@ -569,7 +589,8 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean);
|
||||||
|
|
||||||
void kvm_release_pfn_clean(pfn_t pfn)
|
void kvm_release_pfn_clean(pfn_t pfn)
|
||||||
{
|
{
|
||||||
put_page(pfn_to_page(pfn));
|
if (pfn_valid(pfn))
|
||||||
|
put_page(pfn_to_page(pfn));
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
|
EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
|
||||||
|
|
||||||
|
@ -594,21 +615,25 @@ EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
|
||||||
|
|
||||||
void kvm_set_pfn_dirty(pfn_t pfn)
|
void kvm_set_pfn_dirty(pfn_t pfn)
|
||||||
{
|
{
|
||||||
struct page *page = pfn_to_page(pfn);
|
if (pfn_valid(pfn)) {
|
||||||
if (!PageReserved(page))
|
struct page *page = pfn_to_page(pfn);
|
||||||
SetPageDirty(page);
|
if (!PageReserved(page))
|
||||||
|
SetPageDirty(page);
|
||||||
|
}
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
|
EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
|
||||||
|
|
||||||
void kvm_set_pfn_accessed(pfn_t pfn)
|
void kvm_set_pfn_accessed(pfn_t pfn)
|
||||||
{
|
{
|
||||||
mark_page_accessed(pfn_to_page(pfn));
|
if (pfn_valid(pfn))
|
||||||
|
mark_page_accessed(pfn_to_page(pfn));
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
|
EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
|
||||||
|
|
||||||
void kvm_get_pfn(pfn_t pfn)
|
void kvm_get_pfn(pfn_t pfn)
|
||||||
{
|
{
|
||||||
get_page(pfn_to_page(pfn));
|
if (pfn_valid(pfn))
|
||||||
|
get_page(pfn_to_page(pfn));
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL_GPL(kvm_get_pfn);
|
EXPORT_SYMBOL_GPL(kvm_get_pfn);
|
||||||
|
|
||||||
|
|
Loading…
Reference in a new issue