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author | Marcelo Tosatti <mtosatti@redhat.com> | 2014-02-24 13:59:32 -0300 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-02-26 17:23:32 +0100 |
commit | 404381c5839d67aa0c275ad1da96ef3d3928ca2c (patch) | |
tree | 428dc29ebd433849b621e6238e93e33f9cfca0e2 /arch/x86 | |
parent | 6d0abeca3242a88cab8232e4acd7e2bf088f3bc2 (diff) | |
download | op-kernel-dev-404381c5839d67aa0c275ad1da96ef3d3928ca2c.zip op-kernel-dev-404381c5839d67aa0c275ad1da96ef3d3928ca2c.tar.gz |
KVM: MMU: drop read-only large sptes when creating lower level sptes
Read-only large sptes can be created due to read-only faults as
follows:
- QEMU pagetable entry that maps guest memory is read-only
due to COW.
- Guest read faults such memory, COW is not broken, because
it is a read-only fault.
- Enable dirty logging, large spte not nuked because it is read-only.
- Write-fault on such memory causes guest to loop endlessly
(which must go down to level 1 because dirty logging is enabled).
Fix by dropping large spte when necessary.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/kvm/mmu.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index e50425d..9b53135 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2672,6 +2672,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, break; } + drop_large_spte(vcpu, iterator.sptep); if (!is_shadow_present_pte(*iterator.sptep)) { u64 base_addr = iterator.addr; |