[kvm-devel] [PATCH] KVM: PIT: support mode 3

[Aurelien J. <aur...@au...>]

The in-kernel PIT emulation ignores pending timers if operating
under mode 3, which for example Hurd uses.

This mode should output a square wave, high for (N+1)/2 counts and low
for (N-1)/2 counts. As we only care about the resulting interrupts, the
period is N, and mode 3 is the same as mode 2 with regard to 
interrupts.

Signed-off-by: Aurelien Jarno <aur...@au...>
---
 arch/x86/kvm/i8254.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 1646102..61cc450 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -293,6 +293,7 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val)
 		create_pit_timer(&ps->pit_timer, val, 0);
 		break;
 	case 2:
+	case 3:
 		create_pit_timer(&ps->pit_timer, val, 1);
 		break;
 	default:
-- 
1.5.5

-- 
  .''`.  Aurelien Jarno	            | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   au...@de...         | aur...@au...
   `-    people.debian.org/~aurel32 | www.aurel32.net