From f36281bf7dc6d125780dab76a8b7abdc8042b1a3 Mon Sep 17 00:00:00 2001 From: Josh Boyer Date: Mon, 6 Jan 2014 08:18:13 -0500 Subject: [PATCH] Fix oops in KVM with invalid root_hpa (rhbz 924916) --- ...dle-invalid-root_hpa-at-__direct_map.patch | 40 +++++++++++++++++++ kernel.spec | 9 +++++ 2 files changed, 49 insertions(+) create mode 100644 KVM-MMU-handle-invalid-root_hpa-at-__direct_map.patch diff --git a/KVM-MMU-handle-invalid-root_hpa-at-__direct_map.patch b/KVM-MMU-handle-invalid-root_hpa-at-__direct_map.patch new file mode 100644 index 000000000..a80b25638 --- /dev/null +++ b/KVM-MMU-handle-invalid-root_hpa-at-__direct_map.patch @@ -0,0 +1,40 @@ +Bugzilla: 924916 +Upstream-status: Queued for 3.14 in kvm tree + +From 989c6b34f6a9480e397b170cc62237e89bf4fdb9 Mon Sep 17 00:00:00 2001 +From: Marcelo Tosatti +Date: Thu, 19 Dec 2013 17:28:51 +0000 +Subject: KVM: MMU: handle invalid root_hpa at __direct_map + +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 +Signed-off-by: Paolo Bonzini +--- +diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c +index 40772ef..31a5702 100644 +--- a/arch/x86/kvm/mmu.c ++++ b/arch/x86/kvm/mmu.c +@@ -2659,6 +2659,9 @@ 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, +-- +cgit v0.9.2 diff --git a/kernel.spec b/kernel.spec index 9375b455e..d772fb36c 100644 --- a/kernel.spec +++ b/kernel.spec @@ -715,6 +715,9 @@ Patch25171: elantech-Properly-differentiate-between-clickpads-an.patch Patch25172: xen-netback-Include-header-for-vmalloc.patch +#rhbz 924916 +Patch25179: KVM-MMU-handle-invalid-root_hpa-at-__direct_map.patch + # END OF PATCH DEFINITIONS %endif @@ -1393,6 +1396,9 @@ ApplyPatch elantech-Properly-differentiate-between-clickpads-an.patch ApplyPatch xen-netback-Include-header-for-vmalloc.patch +#rhbz 924916 +ApplyPatch KVM-MMU-handle-invalid-root_hpa-at-__direct_map.patch + # END OF PATCH APPLICATIONS %endif @@ -2207,6 +2213,9 @@ fi # ||----w | # || || %changelog +* Mon Jan 06 2014 Josh Boyer +- Fix oops in KVM with invalid root_hpa (rhbz 924916) + * Sun Jan 05 2014 Josh Boyer - 3.13-0.0.rc7.git0.1 - Linux v3.13-rc7 - Fix xen-netback build failure on ARM