Re: [Qemu-devel] [PATCH v3 2/3] target-i386: calculate vcpu's TSC rate to be migrated

[Haozhong Zhang]

On 11/05/15 09:05, Christian Borntraeger wrote:
> Am 02.11.2015 um 10:40 schrieb James Hogan:
> > On Mon, Nov 02, 2015 at 05:26:42PM +0800, Haozhong Zhang wrote:
> >> The value of the migrated vcpu's TSC rate is determined as below.
> >>  1. If a TSC rate is specified by the cpu option 'tsc-freq', then this
> >>     user-specified value will be used.
> >>  2. If neither a user-specified TSC rate nor a migrated TSC rate is
> >>     present, we will use the TSC rate from KVM (returned by
> >>     KVM_GET_TSC_KHZ).
> >>  3. Otherwise, we will use the migrated TSC rate.
> >>
> >> Signed-off-by: Haozhong Zhang <address@hidden>
> >> ---
> >>  include/sysemu/kvm.h |  2 ++
> >>  kvm-all.c            |  1 +
> >>  target-arm/kvm.c     |  5 +++++
> >>  target-i386/kvm.c    | 33 +++++++++++++++++++++++++++++++++
> >>  target-mips/kvm.c    |  5 +++++
> >>  target-ppc/kvm.c     |  5 +++++
> >>  target-s390x/kvm.c   |  5 +++++
> >>  7 files changed, 56 insertions(+)
> >>
> >> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
> >> index 461ef65..0ec8b98 100644
> >> --- a/include/sysemu/kvm.h
> >> +++ b/include/sysemu/kvm.h
> >> @@ -328,6 +328,8 @@ int kvm_arch_fixup_msi_route(struct 
> >> kvm_irq_routing_entry *route,
> >>  
> >>  int kvm_arch_msi_data_to_gsi(uint32_t data);
> >>  
> >> +int kvm_arch_setup_tsc_khz(CPUState *cpu);
> >> +
> >>  int kvm_set_irq(KVMState *s, int irq, int level);
> >>  int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg);
> >>  
> >> diff --git a/kvm-all.c b/kvm-all.c
> >> index c442838..1ecaf04 100644
> >> --- a/kvm-all.c
> >> +++ b/kvm-all.c
> >> @@ -1757,6 +1757,7 @@ static void do_kvm_cpu_synchronize_post_init(void 
> >> *arg)
> >>  {
> >>      CPUState *cpu = arg;
> >>  
> >> +    kvm_arch_setup_tsc_khz(cpu);
> > 
> > Sorry if this is a stupid question, but why aren't you doing this from
> > the i386 kvm_arch_put_registers when level == KVM_PUT_FULL_STATE, rather
> > than introducing x86 specifics to the generic KVM api?
> > 
> > Cheers
> > James
> 
> I agree. We should try to keep this in x86 code.
> 
> 

As in another reply, I'm going to move the above line to
kvm_arch_put_registers() of target-i386 so that it will not pollute
other targets.

Haozhong