[PATCH 2/4] KVM: Introduce hva_to_gfn() for kvm_handle_hva()

Takuya Yoshikawa
2012-06-15T11:31:44Z

This restricts hva handling in mmu code and makes it easier to extend
kvm_handle_hva() so that it can treat a range of addresses later in this
patch series.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/kvm/book3s_64_mmu_hv.c | 12 +++++-------
arch/x86/kvm/mmu.c | 10 +++-------
include/linux/kvm_host.h | 7 +++++++
3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index d03eb6f..53716dd 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -767,15 +767,13 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,

slots = kvm_memslots(kvm);
kvm_for_each_memslot(memslot, slots) {
- unsigned long start = memslot->userspace_addr;
- unsigned long end;
+ gfn_t gfn = hva_to_gfn(hva, memslot);

- end = start + (memslot->npages << PAGE_SHIFT);
- if (hva >= start && hva < end) {
- gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
+ if (gfn >= memslot->base_gfn &&
+ gfn < memslot->base_gfn + memslot->npages) {
+ gfn_t gfn_offset = gfn - memslot->base_gfn;

- ret = handler(kvm, &memslot->rmap[gfn_offset],
- memslot->base_gfn + gfn_offset);
+ ret = handler(kvm, &memslot->rmap[gfn_offset], gfn);
retval |= ret;
}
}
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a2f3969..ba57b3b 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1199,14 +1199,10 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
slots = kvm_memslots(kvm);

kvm_for_each_memslot(memslot, slots) {
- unsigned long start = memslot->userspace_addr;
- unsigned long end;
-
- end = start + (memslot->npages << PAGE_SHIFT);
- if (hva >= start && hva < end) {
- gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
- gfn_t gfn = memslot->base_gfn + gfn_offset;
+ gfn_t gfn = hva_to_gfn(hva, memslot);

+ if (gfn >= memslot->base_gfn &&
+ gfn < memslot->base_gfn + memslot->npages) {
ret = 0;

for (j = PT_PAGE_TABLE_LEVEL;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 27ac8a4..92b2029 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -740,6 +740,13 @@ static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level)
(base_gfn >> KVM_HPAGE_GFN_SHIFT(level));
}

+static inline gfn_t hva_to_gfn(unsigned long hva, struct kvm_memory_slot *slot)
+{
+ gfn_t gfn_offset = (hva - slot->userspace_addr) >> PAGE_SHIFT;
+
+ return slot->base_gfn + gfn_offset;
+}
+
static inline unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
gfn_t gfn)
{
--
1.7.5.4