KVM: MMU: introduce FNAME(prefetch_gpte)
The only difference between FNAME(update_pte) and FNAME(pte_prefetch)
is that the former is allowed to prefetch gfn from dirty logged slot,
so introduce a common function to prefetch spte
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 36a80ed..f887e4c 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -305,31 +305,43 @@
addr, access);
}
+static bool
+FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
+ u64 *spte, pt_element_t gpte, bool no_dirty_log)
+{
+ unsigned pte_access;
+ gfn_t gfn;
+ pfn_t pfn;
+
+ if (prefetch_invalid_gpte(vcpu, sp, spte, gpte))
+ return false;
+
+ pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);
+
+ gfn = gpte_to_gfn(gpte);
+ pte_access = sp->role.access & gpte_access(vcpu, gpte);
+ protect_clean_gpte(&pte_access, gpte);
+ pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn,
+ no_dirty_log && (pte_access & ACC_WRITE_MASK));
+ if (is_invalid_pfn(pfn))
+ return false;
+
+ /*
+ * we call mmu_set_spte() with host_writable = true because
+ * pte_prefetch_gfn_to_pfn always gets a writable pfn.
+ */
+ mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,
+ NULL, PT_PAGE_TABLE_LEVEL, gfn, pfn, true, true);
+
+ 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;
+ pt_element_t gpte = *(const pt_element_t *)pte;
- gpte = *(const pt_element_t *)pte;
- if (prefetch_invalid_gpte(vcpu, sp, spte, gpte))
- return;
-
- pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);
- pte_access = sp->role.access & gpte_access(vcpu, gpte);
- protect_clean_gpte(&pte_access, gpte);
- pfn = gfn_to_pfn_atomic(vcpu->kvm, gpte_to_gfn(gpte));
- if (is_invalid_pfn(pfn))
- return;
-
- /*
- * we call mmu_set_spte() with host_writable = true because that
- * vcpu->arch.update_pte.pfn was fetched from get_user_pages(write = 1).
- */
- mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,
- NULL, PT_PAGE_TABLE_LEVEL,
- gpte_to_gfn(gpte), pfn, true, true);
+ FNAME(prefetch_gpte)(vcpu, sp, spte, gpte, false);
}
static bool FNAME(gpte_changed)(struct kvm_vcpu *vcpu,
@@ -375,33 +387,14 @@
spte = sp->spt + i;
for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) {
- pt_element_t gpte;
- unsigned pte_access;
- gfn_t gfn;
- pfn_t pfn;
-
if (spte == sptep)
continue;
if (is_shadow_present_pte(*spte))
continue;
- gpte = gptep[i];
-
- if (prefetch_invalid_gpte(vcpu, sp, spte, gpte))
- continue;
-
- pte_access = sp->role.access & gpte_access(vcpu, gpte);
- protect_clean_gpte(&pte_access, gpte);
- gfn = gpte_to_gfn(gpte);
- pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn,
- pte_access & ACC_WRITE_MASK);
- if (is_invalid_pfn(pfn))
+ if (!FNAME(prefetch_gpte)(vcpu, sp, spte, gptep[i], true))
break;
-
- mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,
- NULL, PT_PAGE_TABLE_LEVEL, gfn,
- pfn, true, true);
}
}