[PATCH 14/22] KVM: MMU: Make walk_addr_generic capable for two-level walking

Joerg Roedel
2010-04-27T10:38:53Z

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@amd.com>
---
arch/x86/kvm/paging_tmpl.h | 34 ++++++++++++++++++++++++----------
1 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 7819a6f..8b27026 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -121,8 +121,9 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
gfn_t table_gfn;
unsigned index, pt_access, pte_access;
gpa_t pte_gpa;
+ int offset;
int rsvd_fault = 0;
- u32 error;
+ u32 error = 0;

trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault,
fetch_fault);
@@ -149,13 +150,16 @@ 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)))
- goto not_present;
+ if (kvm_read_guest_page_tdp(vcpu, mmu, table_gfn, &pte, offset,
+ sizeof(pte), &error)) {
+ walker->error_code = error;
+ return 0;
+ }

trace_kvm_mmu_paging_element(pte, walker->level);

@@ -200,15 +204,25 @@ 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);
+
+ real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn),
+ &error);
+ if (real_gpa == UNMAPPED_GVA) {
+ walker->error_code = error;
+ return 0;
+ }
+
+ walker->gfn = real_gpa >> PAGE_SHIFT;

break;
}
@@ -237,7 +251,7 @@ walk:
return 1;

not_present:
- walker->error_code = 0;
+ walker->error_code = error;
goto err;

access_error:
--
1.7.0.4