From: Aurelien Jarno <aurelien@aurel32.net>
Date: Fri, 2 May 2008 15:02:23 +0000 (+0200)
Subject: KVM: PIT: support mode 3
X-Git-Tag: kvm-69rc1~16
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=38df5142b94ffa8f09681ca3ad6f141e3a9b0b8c;p=users%2Fdwmw2%2Flinux.git

KVM: PIT: support mode 3

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 <aurelien@aurel32.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index fcd1825c2fd5a..fba0e4ebb8ebd 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: