Re: [Qemu-devel] [PATCH 4/7 v2] KVM regsync: Add register bitmap parameter to do_kvm_cpu_synchronize_state

[Bhushan Bharat-R65777]

> -----Original Message-----
> From: Jason J. Herne [mailto:address@hidden
> Sent: Thursday, January 10, 2013 8:59 PM
> To: address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden; Bhushan Bharat-R65777;
> address@hidden
> Cc: Jason J. Herne
> Subject: [PATCH 4/7 v2] KVM regsync: Add register bitmap parameter to
> do_kvm_cpu_synchronize_state
> 
> From: "Jason J. Herne" <address@hidden>
> 
> do_kvm_cpu_synchronize_state is called via run_on_cpu, so we can only pass
> a single argument.  Create SyncStateArgs struct for this purpose and add
> register bitmap data member to it.
> 
> Signed-off-by: Jason J. Herne <address@hidden>
> Reviewed-by: Christian Borntraeger <address@hidden>
> ---
>  include/sysemu/kvm.h |    6 ++++++
>  kvm-all.c            |   27 +++++++++++++++++----------
>  2 files changed, 23 insertions(+), 10 deletions(-)
> 
> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
> index e0738ba..193d1f4 100644
> --- a/include/sysemu/kvm.h
> +++ b/include/sysemu/kvm.h
> @@ -223,6 +223,12 @@ int kvm_check_extension(KVMState *s, unsigned int
> extension);
> 
>  uint32_t kvm_arch_get_supported_cpuid(KVMState *env, uint32_t function,
>                                        uint32_t index, int reg);
> +
> +struct kvm_cpu_syncstate_args {
> +    CPUState *cpu;
> +    int regmap;
> +};
> +
>  void kvm_cpu_synchronize_state(CPUArchState *env);
>  void kvm_cpu_synchronize_post_reset(CPUArchState *env);
>  void kvm_cpu_synchronize_post_init(CPUArchState *env);
> diff --git a/kvm-all.c b/kvm-all.c
> index 1aa61bb..77ab72a 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -231,7 +231,7 @@ int kvm_init_vcpu(CPUArchState *env)
> 
>      cpu->kvm_fd = ret;
>      cpu->kvm_state = s;
> -    cpu->kvm_vcpu_dirty = true;
> +    cpu->kvm_vcpu_dirty = KVM_REGSYNC_FULL_STATE;
> 
>      mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
>      if (mmap_size < 0) {
> @@ -1491,20 +1491,27 @@ void kvm_flush_coalesced_mmio_buffer(void)
> 
>  static void do_kvm_cpu_synchronize_state(void *arg)
>  {
> -    CPUState *cpu = arg;
> +    struct kvm_cpu_syncstate_args *args = arg;
> 
> -    if (!cpu->kvm_vcpu_dirty) {
> -        kvm_arch_get_registers(cpu, KVM_REGSYNC_FULL_STATE);
> -        cpu->kvm_vcpu_dirty = true;
> +    /* Do not sync regs that are already dirty */
> +    int regs_to_get = args->regmap & ~args->cpu->kvm_vcpu_dirty;
> +
> +    if (regs_to_get) {
> +        kvm_arch_get_registers(args->cpu, regs_to_get);
> +        args->cpu->kvm_vcpu_dirty |= regs_to_get;
>      }
>  }
> 
>  void kvm_cpu_synchronize_state(CPUArchState *env)
>  {
>      CPUState *cpu = ENV_GET_CPU(env);
> +    struct kvm_cpu_syncstate_args args;
> +
> +    args.cpu = cpu;
> +    args.regmap = KVM_REGSYNC_FULL_STATE;
> 
> -    if (!cpu->kvm_vcpu_dirty) {
> -        run_on_cpu(cpu, do_kvm_cpu_synchronize_state, cpu);
> +    if (args.regmap & ~cpu->kvm_vcpu_dirty) {
> +        run_on_cpu(cpu, do_kvm_cpu_synchronize_state, &args);
>      }
>  }
> 
> @@ -1513,7 +1520,7 @@ void kvm_cpu_synchronize_post_reset(CPUArchState *env)
>      CPUState *cpu = ENV_GET_CPU(env);
> 
>      kvm_arch_put_registers(cpu, KVM_REGSYNC_RESET_STATE);
> -    cpu->kvm_vcpu_dirty = false;
> +    cpu->kvm_vcpu_dirty &= ~KVM_REGSYNC_RESET_STATE;
>  }
> 
>  void kvm_cpu_synchronize_post_init(CPUArchState *env)
> @@ -1521,7 +1528,7 @@ void kvm_cpu_synchronize_post_init(CPUArchState *env)
>      CPUState *cpu = ENV_GET_CPU(env);
> 
>      kvm_arch_put_registers(cpu, KVM_REGSYNC_FULL_STATE);
> -    cpu->kvm_vcpu_dirty = false;
> +    cpu->kvm_vcpu_dirty &= ~KVM_REGSYNC_FULL_STATE;
>  }
> 
>  int kvm_cpu_exec(CPUArchState *env)
> @@ -1540,7 +1547,7 @@ int kvm_cpu_exec(CPUArchState *env)
>      do {
>          if (cpu->kvm_vcpu_dirty) {
>              kvm_arch_put_registers(cpu, KVM_REGSYNC_RUNTIME_STATE);

s/KVM_REGSYNC_RUNTIME_STATE/cpu->kvm_vcpu_dirty


> -            cpu->kvm_vcpu_dirty = false;
> +            cpu->kvm_vcpu_dirty &= ~KVM_REGSYNC_RUNTIME_STATE;

cpu->kvm_vcpu_dirty = 0;

-Bharat

>          }
> 
>          kvm_arch_pre_run(cpu, run);
> --
> 1.7.9.5
>