From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754022AbcARDfJ (ORCPT ); Sun, 17 Jan 2016 22:35:09 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:59312 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752663AbcARDWE (ORCPT ); Sun, 17 Jan 2016 22:22:04 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "P J P" , "Paolo Bonzini" Date: Mon, 18 Jan 2016 03:18:35 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 44/70] kvm: x86: only channel 0 of the i8254 is linked to the HPET In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.247 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.76-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini 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 --- arch/x86/kvm/i8254.c | 1 + arch/x86/kvm/x86.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -437,6 +437,7 @@ void kvm_pit_load_count(struct kvm *kvm, 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); --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3470,7 +3470,8 @@ static int kvm_vm_ioctl_set_pit2(struct 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; }