| From | Luis Henriques <> | Subject | [PATCH 3.5 40/62] KVM: MMU: handle invalid root_hpa at __direct_map | Date | Wed, 5 Mar 2014 14:36:44 +0000 |
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3.5.7.32 -stable review patch. If anyone has any objections, please let me know.
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From: Marcelo Tosatti <mtosatti@redhat.com>
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: Luis Henriques <luis.henriques@canonical.com> --- arch/x86/kvm/mmu.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 57e168e..d6c365f 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2500,6 +2500,9 @@ 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) { unsigned pte_access = ACC_ALL; -- 1.9.0
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