From e5e57e7a03b1cdcb98e4aed135def2a08cbf3257 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 7 Jan 2016 13:50:38 +0100 Subject: kvm: x86: only channel 0 of the i8254 is linked to the HPET While setting the KVM PIT counters in 'kvm_pit_load_count', if 'hpet_legacy_start' is set, the function disables the timer on channel[0], instead of the respective index 'channel'. This is because channels 1-3 are not linked to the HPET. Fix the caller to only activate the special HPET processing for channel 0. Reported-by: P J P Fixes: 0185604c2d82c560dab2f2933a18f797e74ab5a8 Signed-off-by: Paolo Bonzini --- arch/x86/kvm/i8254.c | 1 + arch/x86/kvm/x86.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 08116ff227cc..b0ea42b78ccd 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -420,6 +420,7 @@ void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_s u8 saved_mode; if (hpet_legacy_start) { /* save existing mode for later reenablement */ + WARN_ON(channel != 0); saved_mode = kvm->arch.vpit->pit_state.channels[0].mode; kvm->arch.vpit->pit_state.channels[0].mode = 0xff; /* disable timer */ pit_load_count(kvm, channel, val); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7ffc224bbe41..97592e190413 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3606,7 +3606,8 @@ static int kvm_vm_ioctl_set_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps) sizeof(kvm->arch.vpit->pit_state.channels)); kvm->arch.vpit->pit_state.flags = ps->flags; for (i = 0; i < 3; i++) - kvm_pit_load_count(kvm, i, kvm->arch.vpit->pit_state.channels[i].count, start); + kvm_pit_load_count(kvm, i, kvm->arch.vpit->pit_state.channels[i].count, + start && i == 0); mutex_unlock(&kvm->arch.vpit->pit_state.lock); return 0; } -- cgit v1.2.3