On 23/03/2021 09:58, Roger Pau Monne wrote:
> Such helper is based on the existing functions to fetch a CPUID and
> MSR policies, but uses the xc_cpu_policy_t type to return the data to
> the caller.
>
> Note some helper functions are introduced, those are split from
> xc_cpu_policy_get_system because they will be used by other functions
> also.
>
> No user of the interface introduced on the patch.
>
> Signed-off-by: Roger Pau Monné <roger....@citrix.com>
> ---
> tools/include/xenctrl.h | 4 ++
> tools/libs/guest/xg_cpuid_x86.c | 90 +++++++++++++++++++++++++++++++++
> 2 files changed, 94 insertions(+)
>
> diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
> index ffb3024bfeb..fc8e4b28781 100644
> --- a/tools/include/xenctrl.h
> +++ b/tools/include/xenctrl.h
> @@ -2596,6 +2596,10 @@ typedef struct cpu_policy *xc_cpu_policy_t;
> xc_cpu_policy_t xc_cpu_policy_init(void);
> void xc_cpu_policy_destroy(xc_cpu_policy_t policy);
>
> +/* Retrieve a system policy, or get/set a domains policy. */
> +int xc_cpu_policy_get_system(xc_interface *xch, unsigned int idx,
> + xc_cpu_policy_t policy);
I'd recommend "policy_idx" as the parameter name.
> +static int deserialize_policy(xc_interface *xch, xc_cpu_policy_t policy,
> + unsigned int nr_leaves,
> + const xen_cpuid_leaf_t *leaves,
> + unsigned int nr_msrs, const xen_msr_entry_t
> *msrs)
> +{
> + uint32_t err_leaf = -1, err_subleaf = -1, err_msr = -1;
> + int rc;
> +
> + rc = x86_cpuid_copy_from_buffer(policy->cpuid, leaves, nr_leaves,
> + &err_leaf, &err_subleaf);
> + if ( rc )
> + {
> + ERROR("Failed to deserialise CPUID (err leaf %#x, subleaf %#x) (%d =
> %s)",
> + err_leaf, err_subleaf, -rc, strerror(-rc));
> + return rc;
> + }
> +
> + rc = x86_msr_copy_from_buffer(policy->msr, msrs, nr_msrs, &err_msr);
> + if ( rc )
> + {
> + ERROR("Failed to deserialise MSR (err MSR %#x) (%d = %s)",
> + err_msr, -rc, strerror(-rc));
We possibly want to split out helpers to render the error information.
For MSRs, it ought to be something like
if ( msr == -1 )
// general -ENOMEM etc
else
// MSR-specific error. render index and value.
I think we can probably even depend on MSR-specific errors always being
-EINVAL.
~Andrew
