Re: [Qemu-devel] [PATCH 3/3] i386/kvm: initialize struct at full before ioctl call

[Philippe Mathieu-Daudé]

On 7/30/19 6:01 PM, Andrey Shinkevich wrote:
> Not the whole structure is initialized before passing it to the KVM.
> Reduce the number of Valgrind reports.
> 
> Signed-off-by: Andrey Shinkevich <address@hidden>
> ---
>  target/i386/kvm.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index dbbb137..ed57e31 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -190,6 +190,7 @@ static int kvm_get_tsc(CPUState *cs)
>          return 0;
>      }
>  
> +    memset(&msr_data, 0, sizeof(msr_data));

I wonder the overhead of this one...

>      msr_data.info.nmsrs = 1;
>      msr_data.entries[0].index = MSR_IA32_TSC;
>      env->tsc_valid = !runstate_is_running();
> @@ -1706,6 +1707,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
>  
>      if (has_xsave) {
>          env->xsave_buf = qemu_memalign(4096, sizeof(struct kvm_xsave));
> +        memset(env->xsave_buf, 0, sizeof(struct kvm_xsave));

OK

>      }
>  
>      max_nested_state_len = kvm_max_nested_state_length();
> @@ -3477,6 +3479,7 @@ static int kvm_put_debugregs(X86CPU *cpu)
>          return 0;
>      }
>  
> +    memset(&dbgregs, 0, sizeof(dbgregs));

OK

>      for (i = 0; i < 4; i++) {
>          dbgregs.db[i] = env->dr[i];
>      }

We could remove 'dbgregs.flags = 0;'

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>