From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49850 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751065AbdJBJl5 (ORCPT ); Mon, 2 Oct 2017 05:41:57 -0400 Subject: Patch "KVM: PPC: Book3S HV: Hold kvm->lock around call to kvmppc_update_lpcr" has been added to the 4.13-stable tree To: paulus@ozlabs.org, gregkh@linuxfoundation.org Cc: , From: Date: Mon, 02 Oct 2017 11:41:52 +0200 Message-ID: <150693731223911@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled KVM: PPC: Book3S HV: Hold kvm->lock around call to kvmppc_update_lpcr to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-ppc-book3s-hv-hold-kvm-lock-around-call-to-kvmppc_update_lpcr.patch and it can be found in the queue-4.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From cf5f6f3125241853462334b1bc696f3c3c492178 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Mon, 11 Sep 2017 16:05:30 +1000 Subject: KVM: PPC: Book3S HV: Hold kvm->lock around call to kvmppc_update_lpcr From: Paul Mackerras commit cf5f6f3125241853462334b1bc696f3c3c492178 upstream. Commit 468808bd35c4 ("KVM: PPC: Book3S HV: Set process table for HPT guests on POWER9", 2017-01-30) added a call to kvmppc_update_lpcr() which doesn't hold the kvm->lock mutex around the call, as required. This adds the lock/unlock pair, and for good measure, includes the kvmppc_setup_partition_table() call in the locked region, since it is altering global state of the VM. This error appears not to have any fatal consequences for the host; the consequences would be that the VCPUs could end up running with different LPCR values, or an update to the LPCR value by userspace using the one_reg interface could get overwritten, or the update done by kvmhv_configure_mmu() could get overwritten. Fixes: 468808bd35c4 ("KVM: PPC: Book3S HV: Set process table for HPT guests on POWER9") Signed-off-by: Paul Mackerras Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kvm/book3s_hv.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4187,11 +4187,13 @@ static int kvmhv_configure_mmu(struct kv if ((cfg->process_table & PRTS_MASK) > 24) return -EINVAL; + mutex_lock(&kvm->lock); kvm->arch.process_table = cfg->process_table; kvmppc_setup_partition_table(kvm); lpcr = (cfg->flags & KVM_PPC_MMUV3_GTSE) ? LPCR_GTSE : 0; kvmppc_update_lpcr(kvm, lpcr, LPCR_GTSE); + mutex_unlock(&kvm->lock); return 0; } Patches currently in stable-queue which might be from paulus@ozlabs.org are queue-4.13/kvm-ppc-book3s-hv-hold-kvm-lock-around-call-to-kvmppc_update_lpcr.patch queue-4.13/kvm-ppc-book3s-hv-don-t-access-xive-pipr-register-using-byte-accesses.patch queue-4.13/kvm-ppc-book3s-hv-fix-bug-causing-host-slb-to-be-restored-incorrectly.patch