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path: root/drivers/kvm/paging_tmpl.h
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Diffstat (limited to 'drivers/kvm/paging_tmpl.h')
-rw-r--r--drivers/kvm/paging_tmpl.h68
1 files changed, 38 insertions, 30 deletions
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 6bc41950fbb3..afcd2a8f45bb 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -63,13 +63,15 @@ struct guest_walker {
pt_element_t *ptep;
pt_element_t inherited_ar;
gfn_t gfn;
+ u32 error_code;
};
/*
* Fetch a guest pte for a guest virtual address
*/
-static void FNAME(walk_addr)(struct guest_walker *walker,
- struct kvm_vcpu *vcpu, gva_t addr)
+static int FNAME(walk_addr)(struct guest_walker *walker,
+ struct kvm_vcpu *vcpu, gva_t addr,
+ int write_fault, int user_fault)
{
hpa_t hpa;
struct kvm_memory_slot *slot;
@@ -86,7 +88,7 @@ static void FNAME(walk_addr)(struct guest_walker *walker,
walker->ptep = &vcpu->pdptrs[(addr >> 30) & 3];
root = *walker->ptep;
if (!(root & PT_PRESENT_MASK))
- return;
+ goto not_present;
--walker->level;
}
#endif
@@ -111,11 +113,18 @@ static void FNAME(walk_addr)(struct guest_walker *walker,
ASSERT(((unsigned long)walker->table & PAGE_MASK) ==
((unsigned long)ptep & PAGE_MASK));
- if (is_present_pte(*ptep) && !(*ptep & PT_ACCESSED_MASK))
- *ptep |= PT_ACCESSED_MASK;
-
if (!is_present_pte(*ptep))
- break;
+ goto not_present;
+
+ if (write_fault && !is_writeble_pte(*ptep))
+ if (user_fault || is_write_protection(vcpu))
+ goto access_error;
+
+ if (user_fault && !(*ptep & PT_USER_MASK))
+ goto access_error;
+
+ if (!(*ptep & PT_ACCESSED_MASK))
+ *ptep |= PT_ACCESSED_MASK; /* avoid rmw */
if (walker->level == PT_PAGE_TABLE_LEVEL) {
walker->gfn = (*ptep & PT_BASE_ADDR_MASK)
@@ -146,6 +155,21 @@ static void FNAME(walk_addr)(struct guest_walker *walker,
}
walker->ptep = ptep;
pgprintk("%s: pte %llx\n", __FUNCTION__, (u64)*ptep);
+ return 1;
+
+not_present:
+ walker->error_code = 0;
+ goto err;
+
+access_error:
+ walker->error_code = PFERR_PRESENT_MASK;
+
+err:
+ if (write_fault)
+ walker->error_code |= PFERR_WRITE_MASK;
+ if (user_fault)
+ walker->error_code |= PFERR_USER_MASK;
+ return 0;
}
static void FNAME(release_walker)(struct guest_walker *walker)
@@ -347,7 +371,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
u32 error_code)
{
int write_fault = error_code & PFERR_WRITE_MASK;
- int pte_present = error_code & PFERR_PRESENT_MASK;
int user_fault = error_code & PFERR_USER_MASK;
struct guest_walker walker;
u64 *shadow_pte;
@@ -365,19 +388,19 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
/*
* Look up the shadow pte for the faulting address.
*/
- FNAME(walk_addr)(&walker, vcpu, addr);
- shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
+ r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault);
/*
* The page is not mapped by the guest. Let the guest handle it.
*/
- if (!shadow_pte) {
- pgprintk("%s: not mapped\n", __FUNCTION__);
- inject_page_fault(vcpu, addr, error_code);
+ if (!r) {
+ pgprintk("%s: guest page fault\n", __FUNCTION__);
+ inject_page_fault(vcpu, addr, walker.error_code);
FNAME(release_walker)(&walker);
return 0;
}
+ shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
pgprintk("%s: shadow pte %p %llx\n", __FUNCTION__,
shadow_pte, *shadow_pte);
@@ -399,22 +422,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
* mmio: emulate if accessible, otherwise its a guest fault.
*/
if (is_io_pte(*shadow_pte)) {
- if (may_access(*shadow_pte, write_fault, user_fault))
- return 1;
- pgprintk("%s: io work, no access\n", __FUNCTION__);
- inject_page_fault(vcpu, addr,
- error_code | PFERR_PRESENT_MASK);
- kvm_mmu_audit(vcpu, "post page fault (io)");
- return 0;
- }
-
- /*
- * pte not present, guest page fault.
- */
- if (pte_present && !fixed && !write_pt) {
- inject_page_fault(vcpu, addr, error_code);
- kvm_mmu_audit(vcpu, "post page fault (guest)");
- return 0;
+ return 1;
}
++kvm_stat.pf_fixed;
@@ -429,7 +437,7 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
pt_element_t guest_pte;
gpa_t gpa;
- FNAME(walk_addr)(&walker, vcpu, vaddr);
+ FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0);
guest_pte = *walker.ptep;
FNAME(release_walker)(&walker);