From d99569d9d8562c480e0befab601756b0b7b5d0e0 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Sun, 8 Jan 2017 15:32:34 -0200 Subject: kvm: Allow invtsc migration if tsc-khz is set explicitly We can safely allow a VM to be migrated with invtsc enabled if tsc-khz is set explicitly, because: * QEMU already refuses to start if it can't set the TSC frequency to the configured value. * Management software is already required to keep device configuration (including CPU configuration) the same on migration source and destination. Signed-off-by: Eduardo Habkost Message-Id: <20170108173234.25721-3-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost --- target/i386/kvm.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'target/i386') diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 9744552b8a..3b5282186c 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -963,15 +963,17 @@ int kvm_arch_init_vcpu(CPUState *cs) has_msr_mcg_ext_ctl = has_msr_feature_control = true; } - if ((env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC) && - invtsc_mig_blocker == NULL) { - /* for migration */ - error_setg(&invtsc_mig_blocker, - "State blocked by non-migratable CPU device" - " (invtsc flag)"); - migrate_add_blocker(invtsc_mig_blocker); - /* for savevm */ - vmstate_x86_cpu.unmigratable = 1; + if (!env->user_tsc_khz) { + if ((env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC) && + invtsc_mig_blocker == NULL) { + /* for migration */ + error_setg(&invtsc_mig_blocker, + "State blocked by non-migratable CPU device" + " (invtsc flag)"); + migrate_add_blocker(invtsc_mig_blocker); + /* for savevm */ + vmstate_x86_cpu.unmigratable = 1; + } } cpuid_data.cpuid.padding = 0; -- cgit v1.2.3