From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Habkost Subject: [PATCH 2/4] kvm: Allow invtsc migration if tsc-khz is set explicitly Date: Tue, 27 Dec 2016 17:21:18 -0200 Message-ID: <1482866480-26208-3-git-send-email-ehabkost@redhat.com> References: <1482866480-26208-1-git-send-email-ehabkost@redhat.com> Cc: Paolo Bonzini , Marcelo Tosatti , kvm@vger.kernel.org, Haozhong Zhang To: qemu-devel@nongnu.org Return-path: In-Reply-To: <1482866480-26208-1-git-send-email-ehabkost@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: "Qemu-devel" List-Id: kvm.vger.kernel.org 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. Signed-off-by: Eduardo Habkost --- target/i386/kvm.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index a26290f..6a51399 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -962,15 +962,16 @@ 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; -- 2.7.4