From ece15babfa514e06118f62f4df2c757d6209f4f0 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Wed, 30 Apr 2008 13:23:54 -0300 Subject: [PATCH] KVM: PIT: support mode 4 The in-kernel PIT emulation ignores pending timers if operating under mode 4, which for example DragonFlyBSD uses (and Plan9 too, apparently). Mode 4 seems to be similar to one-shot mode, other than the fact that it starts counting after the next CLK pulse once programmed, while mode 1 starts counting immediately, so add a FIXME to enhance precision. Fixes sourceforge bug 1952988. Signed-off-by: Marcelo Tosatti Acked-by: Sheng Yang Signed-off-by: Avi Kivity --- arch/x86/kvm/i8254.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 4c943eabac..3324d90038 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -288,6 +288,8 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val) * mode 1 is one shot, mode 2 is period, otherwise del timer */ switch (ps->channels[0].mode) { case 1: + /* FIXME: enhance mode 4 precision */ + case 4: create_pit_timer(&ps->pit_timer, val, 0); break; case 2: -- 2.39.5