[PATCH 08/58] KVM: Unify kvm_mmu_pre_write() and kvm_mmu_post_write()

Avi Kivity
2007-06-17T09:43:49Z

Instead of calling two functions and repeating expensive checks, call one
function and provide it with before/after information.

Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/kvm.h | 4 ++--
drivers/kvm/kvm_main.c | 4 ++--
drivers/kvm/mmu.c | 11 ++++-------
3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 7facebd..11c519e 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -525,8 +525,8 @@ int kvm_write_guest(struct kvm_vcpu *vcpu,

unsigned long segment_base(u16 selector);

-void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes);
-void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes);
+void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
+ const u8 *old, const u8 *new, int bytes);
int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva);
void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu);

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 7d68258..b6ad9c6 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1071,18 +1071,18 @@ static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
{
struct page *page;
void *virt;
+ unsigned offset = offset_in_page(gpa);

if (((gpa + bytes - 1) >> PAGE_SHIFT) != (gpa >> PAGE_SHIFT))
return 0;
page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
if (!page)
return 0;
- kvm_mmu_pre_write(vcpu, gpa, bytes);
mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT);
virt = kmap_atomic(page, KM_USER0);
+ kvm_mmu_pte_write(vcpu, gpa, virt + offset, val, bytes);
memcpy(virt + offset_in_page(gpa), val, bytes);
kunmap_atomic(virt, KM_USER0);
- kvm_mmu_post_write(vcpu, gpa, bytes);
return 1;
}

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 2277b7c..b3a83ef 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -1118,7 +1118,7 @@ out:
return r;
}

-static void mmu_pre_write_zap_pte(struct kvm_vcpu *vcpu,
+static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *page,
u64 *spte)
{
@@ -1137,7 +1137,8 @@ static void mmu_pre_write_zap_pte(struct kvm_vcpu *vcpu,
*spte = 0;
}

-void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
+void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
+ const u8 *old, const u8 *new, int bytes)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
struct kvm_mmu_page *page;
@@ -1206,16 +1207,12 @@ void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
spte = __va(page->page_hpa);
spte += page_offset / sizeof(*spte);
while (npte--) {
- mmu_pre_write_zap_pte(vcpu, page, spte);
+ mmu_pte_write_zap_pte(vcpu, page, spte);
++spte;
}
}
}

-void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
-{
-}
-
int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
{
gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);