commit 8f0b1ab6fb045a1324d9435ba00c2940783b0041
author Joerg Roedel <joerg.roedel@amd.com> Thu Jan 28 12:37:56 2010 +0100
committer Marcelo Tosatti <mtosatti@redhat.com> Mon Mar 01 12:36:08 2010 -0300
tree 34db9f9080cea014150249da16348ed3e3e01fc3
parent c45b4fd416f5497b6b38dd70acc0e5b01399e5c9

KVM: Introduce kvm_host_page_size

This patch introduces a generic function to find out the
host page size for a given gfn. This function is needed by
the kvm iommu code. This patch also simplifies the x86
host_mapping_level function.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

virt/kvm/kvm_main.c

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2b0974a..0a360c2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -45,6 +45,7 @@
 #include <linux/spinlock.h>
 #include <linux/compat.h>
 #include <linux/srcu.h>
+#include <linux/hugetlb.h>
 
 #include <asm/processor.h>
 #include <asm/io.h>
@@ -867,6 +868,30 @@
 }
 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
 
+unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
+{
+	struct vm_area_struct *vma;
+	unsigned long addr, size;
+
+	size = PAGE_SIZE;
+
+	addr = gfn_to_hva(kvm, gfn);
+	if (kvm_is_error_hva(addr))
+		return PAGE_SIZE;
+
+	down_read(&current->mm->mmap_sem);
+	vma = find_vma(current->mm, addr);
+	if (!vma)
+		goto out;
+
+	size = vma_kernel_pagesize(vma);
+
+out:
+	up_read(&current->mm->mmap_sem);
+
+	return size;
+}
+
 int memslot_id(struct kvm *kvm, gfn_t gfn)
 {
 	int i;