From b52baab237a0b45cb18b26f529e6490b42574209 Mon Sep 17 00:00:00 2001 From: Liang Li Date: Tue, 8 Dec 2015 09:14:07 +0800 Subject: kvmclock: add a new function to update env->tsc. (Back port from upstream, commit id: 0fd7e098db30e302d27920487f0afec) The commit 317b0a6d8 fixed an issue which caused by the outdated env->tsc value, but the fix lead to 'cpu_synchronize_all_states()' called twice during live migration. The 'cpu_synchronize_all_states()' takes about 130us for a VM which has 4 vcpus, it's a bit expensive. Synchronize the whole CPU context just for updating env->tsc is too wasting, this patch use a new function to update the env->tsc. Comparing to 'cpu_synchronize_all_states()', it only takes about 20us. Change-Id: I7dc8371aa17b005d073249c3732d9a7424f20a25 Signed-off-by: Liang Li Message-Id: <1446695464-27116-2-git-send-email-liang.z.li@intel.com> Signed-off-by: Paolo Bonzini --- qemu/target-i386/kvm_i386.h | 1 + 1 file changed, 1 insertion(+) (limited to 'qemu/target-i386/kvm_i386.h') diff --git a/qemu/target-i386/kvm_i386.h b/qemu/target-i386/kvm_i386.h index e557e94f4..c1b312ba2 100644 --- a/qemu/target-i386/kvm_i386.h +++ b/qemu/target-i386/kvm_i386.h @@ -15,6 +15,7 @@ bool kvm_allows_irq0_override(void); bool kvm_has_smm(void); +void kvm_synchronize_all_tsc(void); void kvm_arch_reset_vcpu(X86CPU *cs); void kvm_arch_do_init_vcpu(X86CPU *cs); -- cgit 1.2.3-korg