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authorMarcelo Tosatti <mtosatti@redhat.com>2010-01-29 17:28:41 -0200
committerAvi Kivity <avi@redhat.com>2010-02-09 19:20:15 +0200
commitee73f656a604d5aa9df86a97102e4e462dd79924 (patch)
tree7d6b179b3b56acb74125777304067b3a905a0738
parent923de3cf5bf12049628019010e36623fca5ef6d1 (diff)
KVM: PIT: control word is write-only
PIT control word (address 0x43) is write-only, reads are undefined. Cc: stable@kernel.org Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
-rw-r--r--arch/x86/kvm/i8254.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 296aba49472..15578f180e5 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -467,6 +467,9 @@ static int pit_ioport_read(struct kvm_io_device *this,
return -EOPNOTSUPP;
addr &= KVM_PIT_CHANNEL_MASK;
+ if (addr == 3)
+ return 0;
+
s = &pit_state->channels[addr];
mutex_lock(&pit_state->lock);