Re: Ping [PATCH v2 14/17] libxc/save: Write X86_{CPUID,MSR}_DATA records

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 27/01/2020 14:34, Andrew Cooper wrote:
> With all other plumbing in place, obtain the CPU Policy from Xen and
> write it into the migration stream.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> ---
> CC: Ian Jackson <Ian.Jackson@xxxxxxxxxx>
> CC: Wei Liu <wl@xxxxxxx>
> ---
>  tools/libxc/xc_sr_common_x86.c   | 50 
> ++++++++++++++++++++++++++++++++++++++++
>  tools/libxc/xc_sr_common_x86.h   |  6 +++++
>  tools/libxc/xc_sr_save_x86_hvm.c |  2 +-
>  tools/libxc/xc_sr_save_x86_pv.c  | 12 +++++++++-
>  4 files changed, 68 insertions(+), 2 deletions(-)
>
> diff --git a/tools/libxc/xc_sr_common_x86.c b/tools/libxc/xc_sr_common_x86.c
> index 8980299e9a..6267655dab 100644
> --- a/tools/libxc/xc_sr_common_x86.c
> +++ b/tools/libxc/xc_sr_common_x86.c
> @@ -42,6 +42,56 @@ int handle_x86_tsc_info(struct xc_sr_context *ctx, struct 
> xc_sr_record *rec)
>      return 0;
>  }
>  
> +int write_x86_cpu_policy_records(struct xc_sr_context *ctx)
> +{
> +    xc_interface *xch = ctx->xch;
> +    struct xc_sr_record cpuid = { .type = REC_TYPE_X86_CPUID_POLICY, };
> +    struct xc_sr_record msrs  = { .type = REC_TYPE_X86_MSR_POLICY, };
> +    uint32_t nr_leaves = 0, nr_msrs = 0;
> +    int rc;
> +
> +    if ( xc_get_cpu_policy_size(xch, &nr_leaves, &nr_msrs) < 0 )
> +    {
> +        PERROR("Unable to get CPU Policy size");
> +        return -1;
> +    }
> +
> +    cpuid.data = malloc(nr_leaves * sizeof(xen_cpuid_leaf_t));
> +    msrs.data  = malloc(nr_msrs   * sizeof(xen_msr_entry_t));
> +    if ( !cpuid.data || !msrs.data )
> +    {
> +        ERROR("Cannot allocate memory for CPU Policy");
> +        rc = -1;
> +        goto out;
> +    }
> +
> +    if ( xc_get_domain_cpu_policy(xch, ctx->domid, &nr_leaves, cpuid.data,
> +                                  &nr_msrs, msrs.data) )
> +    {
> +        PERROR("Unable to get d%d CPU Policy", ctx->domid);
> +        rc = -1;
> +        goto out;
> +    }
> +
> +    cpuid.length = nr_leaves * sizeof(xen_cpuid_leaf_t);
> +    if ( cpuid.length )
> +    {
> +        rc = write_record(ctx, &cpuid);
> +        if ( rc )
> +            goto out;
> +    }
> +
> +    msrs.length = nr_msrs * sizeof(xen_msr_entry_t);
> +    if ( msrs.length )
> +        rc = write_record(ctx, &msrs);
> +
> + out:
> +    free(cpuid.data);
> +    free(msrs.data);
> +
> +    return rc;
> +}
> +
>  int handle_x86_cpuid_policy(struct xc_sr_context *ctx, struct xc_sr_record 
> *rec)
>  {
>      xc_interface *xch = ctx->xch;
> diff --git a/tools/libxc/xc_sr_common_x86.h b/tools/libxc/xc_sr_common_x86.h
> index c458c1aa37..d1050981dd 100644
> --- a/tools/libxc/xc_sr_common_x86.h
> +++ b/tools/libxc/xc_sr_common_x86.h
> @@ -15,6 +15,12 @@ int write_x86_tsc_info(struct xc_sr_context *ctx);
>  int handle_x86_tsc_info(struct xc_sr_context *ctx, struct xc_sr_record *rec);
>  
>  /*
> + * Obtains a domains CPU Policy from Xen, and writes X86_{CPUID,MSR}_POLICY
> + * records into the stream.
> + */
> +int write_x86_cpu_policy_records(struct xc_sr_context *ctx);
> +
> +/*
>   * Parses an X86_CPUID_POLICY record and stashes the content for application
>   * when a STATIC_DATA_END record is encountered.
>   */
> diff --git a/tools/libxc/xc_sr_save_x86_hvm.c 
> b/tools/libxc/xc_sr_save_x86_hvm.c
> index 93bcc1c273..acf9264dec 100644
> --- a/tools/libxc/xc_sr_save_x86_hvm.c
> +++ b/tools/libxc/xc_sr_save_x86_hvm.c
> @@ -172,7 +172,7 @@ static int x86_hvm_setup(struct xc_sr_context *ctx)
>  
>  static int x86_hvm_static_data(struct xc_sr_context *ctx)
>  {
> -    return 0;
> +    return write_x86_cpu_policy_records(ctx);
>  }
>  
>  static int x86_hvm_start_of_stream(struct xc_sr_context *ctx)
> diff --git a/tools/libxc/xc_sr_save_x86_pv.c b/tools/libxc/xc_sr_save_x86_pv.c
> index 46019d962d..c7e246ef4f 100644
> --- a/tools/libxc/xc_sr_save_x86_pv.c
> +++ b/tools/libxc/xc_sr_save_x86_pv.c
> @@ -1054,7 +1054,17 @@ static int x86_pv_setup(struct xc_sr_context *ctx)
>  
>  static int x86_pv_static_data(struct xc_sr_context *ctx)
>  {
> -    return write_x86_pv_info(ctx);
> +    int rc;
> +
> +    rc = write_x86_pv_info(ctx);
> +    if ( rc )
> +        return rc;
> +
> +    rc = write_x86_cpu_policy_records(ctx);
> +    if ( rc )
> +        return rc;
> +
> +    return 0;
>  }
>  
>  static int x86_pv_start_of_stream(struct xc_sr_context *ctx)