[PATCH v4 2/6] KVM: MMU: introduce gfn_to_page_many_atomic() function

Xiao Guangrong
2010-07-01T13:57:39Z

This function not only return the gfn's page but also the page number
after @gfn in the slot

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
include/linux/kvm_host.h | 2 ++
virt/kvm/kvm_main.c | 29 ++++++++++++++++++++++++++++-
2 files changed, 30 insertions(+), 1 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index e0fb543..53f663c 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -288,6 +288,8 @@ 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, bool *enough);
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);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3f976b0..cc360d7 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -923,15 +923,25 @@ 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)
+static unsigned long gfn_to_hva_many(struct kvm *kvm, gfn_t gfn, int *entry)
{
struct kvm_memory_slot *slot;

slot = gfn_to_memslot(kvm, gfn);
+
if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
return bad_hva();
+
+ if (entry)
+ *entry = 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)
@@ -1011,6 +1021,23 @@ 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, bool *enough)
+{
+ unsigned long addr;
+ int entry, ret;
+
+ addr = gfn_to_hva_many(kvm, gfn, &entry);
+ if (kvm_is_error_hva(addr))
+ return -1;
+
+ entry = min(entry, nr_pages);
+ *enough = (entry == nr_pages) ? true : false;
+ ret = __get_user_pages_fast(addr, entry, 1, pages);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
+
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
{
pfn_t pfn;
--
1.6.1.2