Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

KVM: Handle vma regions with no backing page

Browse source 
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:
Anthony Liguori 2008-04-30 15:37:07 -05:00 committed by Avi Kivity
parent d2ebb4103f
commit 2e2e3738af
1 changed files with 37 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

49
virt/kvm/kvm_main.c
View file

@ -532,6 +532,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
struct page *page[1];
unsigned long addr;
int npages;
pfn_t pfn;
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,
NULL);
if (npages != 1) {
get_page(bad_page);
return page_to_pfn(bad_page);
}
if (unlikely(npages != 1)) {
struct vm_area_struct *vma;
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);
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);
@ -569,7 +589,8 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean);
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);
@ -594,21 +615,25 @@ EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
void kvm_set_pfn_dirty(pfn_t pfn)
{
struct page *page = pfn_to_page(pfn);
if (!PageReserved(page))
SetPageDirty(page);
if (pfn_valid(pfn)) {
struct page *page = pfn_to_page(pfn);
if (!PageReserved(page))
SetPageDirty(page);
}
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
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);
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);