From: Paolo Bonzini Date: Thu, 7 Jan 2016 12:50:38 +0000 (+0100) Subject: kvm: x86: only channel 0 of the i8254 is linked to the HPET X-Git-Tag: v3.2.76~27 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef90cf3d0b59e3b1dcfe94d1a241107667e6e96a;p=pandora-kernel.git kvm: x86: only channel 0 of the i8254 is linked to the HPET commit e5e57e7a03b1cdcb98e4aed135def2a08cbf3257 upstream. 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 Signed-off-by: Ben Hutchings --- diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index ab98fe5e2959..aa21aa139694 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -437,6 +437,7 @@ 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 b537df859926..80c6d6835805 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3470,7 +3470,8 @@ 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 r; }