From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:40717 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754773AbcAYAAe (ORCPT ); Sun, 24 Jan 2016 19:00:34 -0500 Subject: Patch "KVM: x86: expose MSR_TSC_AUX to userspace" has been added to the 4.4-stable tree To: pbonzini@redhat.com, gregkh@linuxfoundation.org, rkrcmar@redhat.com Cc: , From: Date: Sun, 24 Jan 2016 16:00:31 -0800 Message-ID: <145368003119599@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: x86: expose MSR_TSC_AUX to userspace to the 4.4-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-x86-expose-msr_tsc_aux-to-userspace.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 9dbe6cf941a6fe82933aef565e4095fb10f65023 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 12 Nov 2015 14:49:17 +0100 Subject: KVM: x86: expose MSR_TSC_AUX to userspace From: Paolo Bonzini commit 9dbe6cf941a6fe82933aef565e4095fb10f65023 upstream. If we do not do this, it is not properly saved and restored across migration. Windows notices due to its self-protection mechanisms, and is very upset about it (blue screen of death). Cc: Radim Krcmar Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -951,7 +951,7 @@ static u32 msrs_to_save[] = { MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR, #endif MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA, - MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS + MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX, }; static unsigned num_msrs_to_save; @@ -4006,16 +4006,17 @@ static void kvm_init_msr_list(void) /* * Even MSRs that are valid in the host may not be exposed - * to the guests in some cases. We could work around this - * in VMX with the generic MSR save/load machinery, but it - * is not really worthwhile since it will really only - * happen with nested virtualization. + * to the guests in some cases. */ switch (msrs_to_save[i]) { case MSR_IA32_BNDCFGS: if (!kvm_x86_ops->mpx_supported()) continue; break; + case MSR_TSC_AUX: + if (!kvm_x86_ops->rdtscp_supported()) + continue; + break; default: break; } Patches currently in stable-queue which might be from pbonzini@redhat.com are queue-4.4/kvm-x86-correctly-print-ac-in-traces.patch queue-4.4/kvm-x86-expose-msr_tsc_aux-to-userspace.patch queue-4.4/kvm-x86-fix-vmwrite-to-secondary_vm_exec_control.patch