git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From foo@baz Thu Feb  1 13:45:42 CET 2018
   2 From: Liran Alon <liran.alon@oracle.com>
   3 Date: Sun, 5 Nov 2017 16:07:43 +0200
   4 Subject: KVM: nVMX: Fix vmx_check_nested_events() return value in case an event was reinjected to L2
   5
   6 From: Liran Alon <liran.alon@oracle.com>
   7
   8
   9 [ Upstream commit 917dc6068bc12a2dafffcf0e9d405ddb1b8780cb ]
  10
  11 vmx_check_nested_events() should return -EBUSY only in case there is a
  12 pending L1 event which requires a VMExit from L2 to L1 but such a
  13 VMExit is currently blocked. Such VMExits are blocked either
  14 because nested_run_pending=1 or an event was reinjected to L2.
  15 vmx_check_nested_events() should return 0 in case there are no
  16 pending L1 events which requires a VMExit from L2 to L1 or if
  17 a VMExit from L2 to L1 was done internally.
  18
  19 However, upstream commit which introduced blocking in case an event was
  20 reinjected to L2 (commit acc9ab601327 ("KVM: nVMX: Fix pending events
  21 injection")) contains a bug: It returns -EBUSY even if there are no
  22 pending L1 events which requires VMExit from L2 to L1.
  23
  24 This commit fix this issue.
  25
  26 Fixes: acc9ab601327 ("KVM: nVMX: Fix pending events injection")
  27
  28 Signed-off-by: Liran Alon <liran.alon@oracle.com>
  29 Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
  30 Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
  31 Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
  32 Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
  33 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  34 ---
  35  arch/x86/kvm/vmx.c |   13 ++++++-------
  36  1 file changed, 6 insertions(+), 7 deletions(-)
  37
  38 --- a/arch/x86/kvm/vmx.c
  39 +++ b/arch/x86/kvm/vmx.c
  40 @@ -11114,13 +11114,12 @@ static int vmx_check_nested_events(struc
  41  {
  42         struct vcpu_vmx *vmx = to_vmx(vcpu);
  43         unsigned long exit_qual;
  44 -
  45 -       if (kvm_event_needs_reinjection(vcpu))
  46 -               return -EBUSY;
  47 +       bool block_nested_events =
  48 +           vmx->nested.nested_run_pending || kvm_event_needs_reinjection(vcpu);
  49
  50         if (vcpu->arch.exception.pending &&
  51                 nested_vmx_check_exception(vcpu, &exit_qual)) {
  52 -               if (vmx->nested.nested_run_pending)
  53 +               if (block_nested_events)
  54                         return -EBUSY;
  55                 nested_vmx_inject_exception_vmexit(vcpu, exit_qual);
  56                 vcpu->arch.exception.pending = false;
  57 @@ -11129,14 +11128,14 @@ static int vmx_check_nested_events(struc
  58
  59         if (nested_cpu_has_preemption_timer(get_vmcs12(vcpu)) &&
  60             vmx->nested.preemption_timer_expired) {
  61 -               if (vmx->nested.nested_run_pending)
  62 +               if (block_nested_events)
  63                         return -EBUSY;
  64                 nested_vmx_vmexit(vcpu, EXIT_REASON_PREEMPTION_TIMER, 0, 0);
  65                 return 0;
  66         }
  67
  68         if (vcpu->arch.nmi_pending && nested_exit_on_nmi(vcpu)) {
  69 -               if (vmx->nested.nested_run_pending)
  70 +               if (block_nested_events)
  71                         return -EBUSY;
  72                 nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI,
  73                                   NMI_VECTOR | INTR_TYPE_NMI_INTR |
  74 @@ -11152,7 +11151,7 @@ static int vmx_check_nested_events(struc
  75
  76         if ((kvm_cpu_has_interrupt(vcpu) || external_intr) &&
  77             nested_exit_on_intr(vcpu)) {
  78 -               if (vmx->nested.nested_run_pending)
  79 +               if (block_nested_events)
  80                         return -EBUSY;
  81                 nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT, 0, 0);
  82                 return 0;