Re: [PATCH 1/2] target/i386/sev: Use local variable for kvm_sev_launch_start

[Dr. David Alan Gilbert]

* Dov Murik (dovmurik@linux.ibm.com) wrote:
> The struct kvm_sev_launch_start has a constant and small size, and
> therefore we can use a regular local variable for it instead of
> allocating and freeing heap memory for it.
> 
> Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  target/i386/sev.c | 23 ++++++++++-------------
>  1 file changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/target/i386/sev.c b/target/i386/sev.c
> index 4c64c68244..0062566c71 100644
> --- a/target/i386/sev.c
> +++ b/target/i386/sev.c
> @@ -647,31 +647,29 @@ sev_launch_start(SevGuestState *sev)
>      gsize sz;
>      int ret = 1;
>      int fw_error, rc;
> -    struct kvm_sev_launch_start *start;
> +    struct kvm_sev_launch_start start = {
> +        .handle = sev->handle, .policy = sev->policy
> +    };
>      guchar *session = NULL, *dh_cert = NULL;
>  
> -    start = g_new0(struct kvm_sev_launch_start, 1);
> -
> -    start->handle = sev->handle;
> -    start->policy = sev->policy;
>      if (sev->session_file) {
>          if (sev_read_file_base64(sev->session_file, &session, &sz) < 0) {
>              goto out;
>          }
> -        start->session_uaddr = (unsigned long)session;
> -        start->session_len = sz;
> +        start.session_uaddr = (unsigned long)session;
> +        start.session_len = sz;
>      }
>  
>      if (sev->dh_cert_file) {
>          if (sev_read_file_base64(sev->dh_cert_file, &dh_cert, &sz) < 0) {
>              goto out;
>          }
> -        start->dh_uaddr = (unsigned long)dh_cert;
> -        start->dh_len = sz;
> +        start.dh_uaddr = (unsigned long)dh_cert;
> +        start.dh_len = sz;
>      }
>  
> -    trace_kvm_sev_launch_start(start->policy, session, dh_cert);
> -    rc = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_START, start, &fw_error);
> +    trace_kvm_sev_launch_start(start.policy, session, dh_cert);
> +    rc = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_START, &start, &fw_error);
>      if (rc < 0) {
>          error_report("%s: LAUNCH_START ret=%d fw_error=%d '%s'",
>                  __func__, ret, fw_error, fw_error_to_str(fw_error));
> @@ -679,11 +677,10 @@ sev_launch_start(SevGuestState *sev)
>      }
>  
>      sev_set_guest_state(sev, SEV_STATE_LAUNCH_UPDATE);
> -    sev->handle = start->handle;
> +    sev->handle = start.handle;
>      ret = 0;
>  
>  out:
> -    g_free(start);
>      g_free(session);
>      g_free(dh_cert);
>      return ret;
> -- 
> 2.25.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK