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KVM: MMU: Calculate correct base gfn for direct non-DIR level

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In Document/kvm/mmu.txt:
  gfn:
    Either the guest page table containing the translations shadowed by this
    page, or the base page frame for linear translations. See role.direct.

But in __direct_map(), the base gfn calculation is incorrect,
it does not calculate correctly when level=3 or 4.

Fix by using PT64_LVL_ADDR_MASK() which accounts for all levels correctly.

Reported-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Lai Jiangshan 2010-05-26 16:48:25 +08:00 committed by Avi Kivity
parent 2032a93d66
commit c9fa0b3bef
1 changed files with 4 additions and 1 deletions
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5
arch/x86/kvm/mmu.c
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@ -2020,7 +2020,10 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
}
if (*iterator.sptep == shadow_trap_nonpresent_pte) {
pseudo_gfn = (iterator.addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
u64 base_addr = iterator.addr;
base_addr &= PT64_LVL_ADDR_MASK(iterator.level);
pseudo_gfn = base_addr >> PAGE_SHIFT;
sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
iterator.level - 1,
1, ACC_ALL, iterator.sptep);