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Commit e5e57e7a authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

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: default avatarP J P <pjp@fedoraproject.org>
Fixes: 0185604c
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 16830985

arch/x86/kvm/i8254.c

+1 −0
Original line number Diff line number Diff line
@@ -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);

arch/x86/kvm/x86.c

+2 −1
Original line number Diff line number Diff line
@@ -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;

}