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| author |   Marcelo Tosatti <mtosatti@redhat.com> | 2008-04-30 13:23:54 -0300 |
|---|---|---|
| committer |   Avi Kivity <avi@qumranet.com> | 2008-05-04 14:44:46 +0300 |
| commit | ece15babfa514e06118f62f4df2c757d6209f4f0 (patch) | |
| tree | 46eadfa87b6adb88a2252c15f0468e8330968001 /arch/x86/kvm | |
| parent | KVM: x86 emulator: disable writeback on lmsw (diff) | |
| download | linux-dev-ece15babfa514e06118f62f4df2c757d6209f4f0.tar.xz linux-dev-ece15babfa514e06118f62f4df2c757d6209f4f0.zip | |
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 <mtosatti@redhat.com>
Acked-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/i8254.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 4c943eabacc3..3324d90038e4 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: |