[PATCH 15/29] KVM: MMU: Make walk_addr_generic capable for two-level walking

From: Joerg Roedel
Date: Fri Sep 10 2010 - 11:38:35 EST


This patch uses kvm_read_guest_page_tdp to make the
walk_addr_generic functions suitable for two-level page
table walking.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/kvm/paging_tmpl.h | 30 +++++++++++++++++++++++-------
1 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index eefe363..f4e09d3 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -124,6 +124,8 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
unsigned index, pt_access, uninitialized_var(pte_access);
gpa_t pte_gpa;
bool eperm, present, rsvd_fault;
+ int offset;
+ u32 access = 0;

trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault,
fetch_fault);
@@ -153,12 +155,14 @@ walk:
index = PT_INDEX(addr, walker->level);

table_gfn = gpte_to_gfn(pte);
- pte_gpa = gfn_to_gpa(table_gfn);
- pte_gpa += index * sizeof(pt_element_t);
+ offset = index * sizeof(pt_element_t);
+ pte_gpa = gfn_to_gpa(table_gfn) + offset;
walker->table_gfn[walker->level - 1] = table_gfn;
walker->pte_gpa[walker->level - 1] = pte_gpa;

- if (kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte))) {
+ if (kvm_read_guest_page_mmu(vcpu, mmu, table_gfn, &pte,
+ offset, sizeof(pte),
+ PFERR_USER_MASK|PFERR_WRITE_MASK)) {
present = false;
break;
}
@@ -209,15 +213,27 @@ walk:
is_large_pte(pte) &&
mmu->root_level == PT64_ROOT_LEVEL)) {
int lvl = walker->level;
+ gpa_t real_gpa;
+ gfn_t gfn;

- walker->gfn = gpte_to_gfn_lvl(pte, lvl);
- walker->gfn += (addr & PT_LVL_OFFSET_MASK(lvl))
- >> PAGE_SHIFT;
+ gfn = gpte_to_gfn_lvl(pte, lvl);
+ gfn += (addr & PT_LVL_OFFSET_MASK(lvl)) >> PAGE_SHIFT;

if (PTTYPE == 32 &&
walker->level == PT_DIRECTORY_LEVEL &&
is_cpuid_PSE36())
- walker->gfn += pse36_gfn_delta(pte);
+ gfn += pse36_gfn_delta(pte);
+
+ access |= write_fault ? PFERR_WRITE_MASK : 0;
+ access |= fetch_fault ? PFERR_FETCH_MASK : 0;
+ access |= user_fault ? PFERR_USER_MASK : 0;
+
+ real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn),
+ access);
+ if (real_gpa == UNMAPPED_GVA)
+ return 0;
+
+ walker->gfn = real_gpa >> PAGE_SHIFT;

break;
}
--
1.7.0.4


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