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[Qemu-devel] [PULL 13/13] kvm: Allow invtsc migration if tsc-khz is set
From: |
Eduardo Habkost |
Subject: |
[Qemu-devel] [PULL 13/13] kvm: Allow invtsc migration if tsc-khz is set explicitly |
Date: |
Mon, 23 Jan 2017 21:27:38 -0200 |
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 <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Eduardo Habkost <address@hidden>
---
target/i386/kvm.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
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;
--
2.11.0.259.g40922b1
- [Qemu-devel] [PULL 03/13] i386: Return migration-safe field on query-cpu-definitions, (continued)
- [Qemu-devel] [PULL 03/13] i386: Return migration-safe field on query-cpu-definitions, Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 05/13] arch_init: Remove unnecessary default_config_files table, Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 04/13] vl: Ensure the numa_post_machine_init func in the appropriate location, Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 06/13] pc: cleanup: move smbios_set_cpuid() into pc_build_smbios(), Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 07/13] pc: don't return cpu pointer from pc_new_cpu() as it's not needed anymore, Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 09/13] MAINTAINERS: Add an entry for hw/core/null-machine.c, Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 08/13] machine: Make possible_cpu_arch_ids() return const pointer, Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 10/13] qemu-options: Rename variables on the -numa "cpus" option, Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 11/13] hw/core/null-machine: Add the possibility to instantiate a CPU and RAM, Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 12/13] kvm: Simplify invtsc check, Eduardo Habkost, 2017/01/23
- [Qemu-devel] [PULL 13/13] kvm: Allow invtsc migration if tsc-khz is set explicitly,
Eduardo Habkost <=
- Re: [Qemu-devel] [PULL 00/13] x86, machine, numa queue (2017-01-23), Peter Maydell, 2017/01/24
- Re: [Qemu-devel] [PULL 00/13] x86, machine, numa queue (2017-01-23), Peter Maydell, 2017/01/24