Commit 9bf49602 authored Dec 19, 2013 by Marcelo Tosatti Committed by Greg Kroah-Hartman Mar 31, 2014

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>

parent dc48b3de

arch/x86/kvm/mmu.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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,