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Commit c9fa0b3b authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Avi Kivity
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KVM: MMU: Calculate correct base gfn for direct non-DIR level 



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: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 2032a93d

arch/x86/kvm/mmu.c

+4 −1
Original line number Diff line number Diff line
@@ -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);