From ee73f656a604d5aa9df86a97102e4e462dd79924 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Fri, 29 Jan 2010 17:28:41 -0200 Subject: [PATCH] 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 --- arch/x86/kvm/i8254.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 296aba49472a..15578f180e59 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);