[PATCH 05/11] kvm: Introduce kvm_host_page_size

Joerg Roedel
2010-01-28T11:37:56Z

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>
---
arch/x86/kvm/mmu.c | 18 ++----------------
include/linux/kvm_host.h | 1 +
virt/kvm/kvm_main.c | 25 +++++++++++++++++++++++++
3 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ff2b2e8..226fa8e 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -467,24 +467,10 @@ static int has_wrprotected_page(struct kvm *kvm,

static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
{
- unsigned long page_size = PAGE_SIZE;
- struct vm_area_struct *vma;
- unsigned long addr;
+ unsigned long page_size;
int i, ret = 0;

- addr = gfn_to_hva(kvm, gfn);
- if (kvm_is_error_hva(addr))
- return PT_PAGE_TABLE_LEVEL;
-
- down_read(&current->mm->mmap_sem);
- vma = find_vma(current->mm, addr);
- if (!vma)
- goto out;
-
- page_size = vma_kernel_pagesize(vma);
-
-out:
- up_read(&current->mm->mmap_sem);
+ page_size = kvm_host_page_size(kvm, gfn);

for (i = PT_PAGE_TABLE_LEVEL;
i < (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES); ++i) {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index dfde04b..a946abc 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -300,6 +300,7 @@ int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len);
int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len);
struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn);
int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn);
+unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn);
void mark_page_dirty(struct kvm *kvm, gfn_t gfn);

void kvm_vcpu_block(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 7c5c873..87a4a77 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>
@@ -884,6 +885,30 @@ int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
}
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;
--
1.6.6