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| author | Marcelo Tosatti <mtosatti@redhat.com> | 2013-12-19 15:28:51 -0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-31 09:58:14 -0700 |
| commit | 9bf49602a4129a4bd97526802c34b5e4e76dbc2e (patch) | |
| tree | d30f36b54265ec95a43558f2084b435573af0781 | |
| parent | dc48b3deaebfbd6c508d258a40d417a38fa0299d (diff) | |
| download | lwn-9bf49602a4129a4bd97526802c34b5e4e76dbc2e.tar.gz lwn-9bf49602a4129a4bd97526802c34b5e4e76dbc2e.zip | |
KVM: MMU: handle invalid root_hpa at __direct_map
commit 989c6b34f6a9480e397b170cc62237e89bf4fdb9 upstream.
It is possible for __direct_map to be called on invalid root_hpa
(-1), two examples:
1) try_async_pf -> can_do_async_pf
-> vmx_interrupt_allowed -> nested_vmx_vmexit
2) vmx_handle_exit -> vmx_interrupt_allowed -> nested_vmx_vmexit
Then to load_vmcs12_host_state and kvm_mmu_reset_context.
Check for this possibility, let fault exception be regenerated.
BZ: https://bugzilla.redhat.com/show_bug.cgi?id=924916
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/mmu.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 004cc87b781c..9a4605454afa 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2585,6 +2585,9 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, int emulate = 0; gfn_t pseudo_gfn; + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) + return 0; + for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) { if (iterator.level == level) { mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, |