[PATCH v3 5/6] KVM: MMU: abstract invalid guest pte mapping

Xiao Guangrong
2010-11-19T09:00:35Z

Introduce a common function to map invalid gpte

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
arch/x86/kvm/mmu.c | 3 --
arch/x86/kvm/paging_tmpl.h | 71 +++++++++++++++++++++++---------------------
2 files changed, 37 insertions(+), 37 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d878dd1..e3d2ee0 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3074,9 +3074,6 @@ static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
return;
}

- if (is_rsvd_bits_set(&vcpu->arch.mmu, *(u64 *)new, PT_PAGE_TABLE_LEVEL))
- return;
-
++vcpu->kvm->stat.mmu_pte_updated;
if (!sp->role.cr4_pae)
paging32_update_pte(vcpu, sp, spte, new);
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 60f00db..dfb906f 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -299,25 +299,42 @@ static int FNAME(walk_addr_nested)(struct guest_walker *walker,
addr, access);
}

+static bool FNAME(map_invalid_gpte)(struct kvm_vcpu *vcpu,
+ struct kvm_mmu_page *sp, u64 *spte,
+ pt_element_t gpte)
+{
+ u64 nonpresent = shadow_trap_nonpresent_pte;
+
+ if (is_rsvd_bits_set(&vcpu->arch.mmu, gpte, PT_PAGE_TABLE_LEVEL))
+ goto no_present;
+
+ if (!is_present_gpte(gpte)) {
+ if (!sp->unsync)
+ nonpresent = shadow_notrap_nonpresent_pte;
+ goto no_present;
+ }
+
+ if (!(gpte & PT_ACCESSED_MASK))
+ goto no_present;
+
+ return false;
+
+no_present:
+ drop_spte(vcpu->kvm, spte, nonpresent);
+ return true;
+}
+
static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
u64 *spte, const void *pte)
{
pt_element_t gpte;
unsigned pte_access;
pfn_t pfn;
- u64 new_spte;

gpte = *(const pt_element_t *)pte;
- if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK)) {
- if (!is_present_gpte(gpte)) {
- if (sp->unsync)
- new_spte = shadow_trap_nonpresent_pte;
- else
- new_spte = shadow_notrap_nonpresent_pte;
- __set_spte(spte, new_spte);
- }
+ if (FNAME(map_invalid_gpte)(vcpu, sp, spte, gpte))
return;
- }
+
pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);
pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
if (gpte_to_gfn(gpte) != vcpu->arch.update_pte.gfn)
@@ -364,7 +381,6 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
u64 *sptep)
{
struct kvm_mmu_page *sp;
- struct kvm_mmu *mmu = &vcpu->arch.mmu;
pt_element_t *gptep = gw->prefetch_ptes;
u64 *spte;
int i;
@@ -395,16 +411,7 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,

gpte = gptep[i];

- if (is_rsvd_bits_set(mmu, gpte, PT_PAGE_TABLE_LEVEL))
- continue;
-
- if (!is_present_gpte(gpte)) {
- if (!sp->unsync)
- __set_spte(spte, shadow_notrap_nonpresent_pte);
- continue;
- }
-
- if (!(gpte & PT_ACCESSED_MASK))
+ if (FNAME(map_invalid_gpte)(vcpu, sp, spte, gpte))
continue;

pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
@@ -761,7 +768,6 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
pt_element_t gpte;
gpa_t pte_gpa;
gfn_t gfn;
- bool rsvd_bits_set;

if (!is_shadow_present_pte(sp->spt[i]))
continue;
@@ -773,18 +779,15 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
return -EINVAL;

gfn = gpte_to_gfn(gpte);
- rsvd_bits_set = is_rsvd_bits_set(&vcpu->arch.mmu, gpte,
- PT_PAGE_TABLE_LEVEL);
- if (rsvd_bits_set || gfn != sp->gfns[i] ||
- !is_present_gpte(gpte) || !(gpte & PT_ACCESSED_MASK)) {
- u64 nonpresent;
-
- if (rsvd_bits_set || is_present_gpte(gpte) ||
- sp->unsync)
- nonpresent = shadow_trap_nonpresent_pte;
- else
- nonpresent = shadow_notrap_nonpresent_pte;
- drop_spte(vcpu->kvm, &sp->spt[i], nonpresent);
+
+ if (FNAME(map_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) {
+ kvm_flush_remote_tlbs(vcpu->kvm);
+ continue;
+ }
+
+ if (gfn != sp->gfns[i]) {
+ drop_spte(vcpu->kvm, &sp->spt[i],
+ shadow_trap_nonpresent_pte);
kvm_flush_remote_tlbs(vcpu->kvm);
continue;
}
--
1.7.0.4