[PATCH 36/58] KVM: MMU: Fold fix_read_pf() into set_pte_common()

Avi Kivity
2007-06-17T09:44:17Z

drivers/kvm/mmu.c | 17 -----------------
drivers/kvm/paging_tmpl.h | 34 +++++++++++++++++++++++-----------
2 files changed, 23 insertions(+), 28 deletions(-)

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index a763150..2079d69 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -972,23 +972,6 @@ static void inject_page_fault(struct kvm_vcpu *vcpu,
kvm_arch_ops->inject_page_fault(vcpu, addr, err_code);
}

-static inline int fix_read_pf(u64 *shadow_ent)
-{
- if ((*shadow_ent & PT_SHADOW_USER_MASK) &&
- !(*shadow_ent & PT_USER_MASK)) {
- /*
- * If supervisor write protect is disabled, we shadow kernel
- * pages as user pages so we can trap the write access.
- */
- *shadow_ent |= PT_USER_MASK;
- *shadow_ent &= ~PT_WRITABLE_MASK;
-
- return 1;
-
- }
- return 0;
-}
-
static void paging_free(struct kvm_vcpu *vcpu)
{
nonpaging_free(vcpu);
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 7e998d1..869582b 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -197,6 +197,7 @@ static void FNAME(set_pte_common)(struct kvm_vcpu *vcpu,
gpa_t gaddr,
pt_element_t *gpte,
u64 access_bits,
+ int write_fault,
gfn_t gfn)
{
hpa_t paddr;
@@ -219,6 +220,17 @@ static void FNAME(set_pte_common)(struct kvm_vcpu *vcpu,

*shadow_pte |= paddr;

+ if (!write_fault && (*shadow_pte & PT_SHADOW_USER_MASK) &&
+ !(*shadow_pte & PT_USER_MASK)) {
+ /*
+ * If supervisor write protect is disabled, we shadow kernel
+ * pages as user pages so we can trap the write access.
+ */
+ *shadow_pte |= PT_USER_MASK;
+ *shadow_pte &= ~PT_WRITABLE_MASK;
+ access_bits &= ~PT_WRITABLE_MASK;
+ }
+
if (access_bits & PT_WRITABLE_MASK) {
struct kvm_mmu_page *shadow;

@@ -242,13 +254,14 @@ static void FNAME(set_pte_common)(struct kvm_vcpu *vcpu,
}

static void FNAME(set_pte)(struct kvm_vcpu *vcpu, pt_element_t *gpte,
- u64 *shadow_pte, u64 access_bits, gfn_t gfn)
+ u64 *shadow_pte, u64 access_bits,
+ int write_fault, gfn_t gfn)
{
ASSERT(*shadow_pte == 0);
access_bits &= *gpte;
*shadow_pte = (*gpte & PT_PTE_COPY_MASK);
FNAME(set_pte_common)(vcpu, shadow_pte, *gpte & PT_BASE_ADDR_MASK,
- gpte, access_bits, gfn);
+ gpte, access_bits, write_fault, gfn);
}

static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
@@ -262,12 +275,13 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK))
return;
pgprintk("%s: gpte %llx spte %p\n", __FUNCTION__, (u64)gpte, spte);
- FNAME(set_pte)(vcpu, &gpte, spte, PT_USER_MASK | PT_WRITABLE_MASK,
+ FNAME(set_pte)(vcpu, &gpte, spte, PT_USER_MASK | PT_WRITABLE_MASK, 0,
(gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT);
}

static void FNAME(set_pde)(struct kvm_vcpu *vcpu, pt_element_t *gpde,
- u64 *shadow_pte, u64 access_bits, gfn_t gfn)
+ u64 *shadow_pte, u64 access_bits, int write_fault,
+ gfn_t gfn)
{
gpa_t gaddr;

@@ -279,14 +293,14 @@ static void FNAME(set_pde)(struct kvm_vcpu *vcpu, pt_element_t *gpde,
(32 - PT32_DIR_PSE36_SHIFT);
*shadow_pte = *gpde & PT_PTE_COPY_MASK;
FNAME(set_pte_common)(vcpu, shadow_pte, gaddr,
- gpde, access_bits, gfn);
+ gpde, access_bits, write_fault, gfn);
}

/*
* Fetch a shadow pte for a specific level in the paging hierarchy.
*/
static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
- struct guest_walker *walker)
+ struct guest_walker *walker, int write_fault)
{
hpa_t shadow_addr;
int level;
@@ -351,12 +365,12 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
if (prev_shadow_ent)
*prev_shadow_ent |= PT_SHADOW_PS_MARK;
FNAME(set_pde)(vcpu, guest_ent, shadow_ent,
- walker->inherited_ar, walker->gfn);
+ walker->inherited_ar, write_fault, walker->gfn);
} else {
ASSERT(walker->level == PT_PAGE_TABLE_LEVEL);
FNAME(set_pte)(vcpu, guest_ent, shadow_ent,
walker->inherited_ar,
- walker->gfn);
+ write_fault, walker->gfn);
}
return shadow_ent;
}
@@ -489,7 +503,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
return 0;
}

- shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
+ shadow_pte = FNAME(fetch)(vcpu, addr, &walker, write_fault);
pgprintk("%s: shadow pte %p %llx\n", __FUNCTION__,
shadow_pte, *shadow_pte);

@@ -499,8 +513,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
if (write_fault)
fixed = FNAME(fix_write_pf)(vcpu, shadow_pte, &walker, addr,
user_fault, &write_pt);
- else
- fixed = fix_read_pf(shadow_pte);

pgprintk("%s: updated shadow pte %p %llx\n", __FUNCTION__,
shadow_pte, *shadow_pte);