Re: [PATCH v2 1/2] x86/hvm/trace: Use a different trace type for AMD processors

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 23/05/2024 3:10 pm, George Dunlap wrote:
> A long-standing usability sub-optimality with xenalyze is the
> necessity to specify `--svm-mode` when analyzing AMD processors.  This
> fundamentally comes about because the same trace event ID is used for
> both VMX and SVM, but the contents of the trace must be interpreted
> differently.
>
> Instead, allocate separate trace events for VMX and SVM vmexits in
> Xen; this will allow all readers to properly interpret the meaning of
> the vmexit reason.
>
> In xenalyze, first remove the redundant call to init_hvm_data();
> there's no way to get to hvm_vmexit_process() without it being already
> initialized by the set_vcpu_type call in hvm_process().
>
> Replace this with set_hvm_exit_reson_data(), and move setting of
> hvm->exit_reason_* into that function.
>
> Modify hvm_process and hvm_vmexit_process to handle all four potential
> values appropriately.
>
> If SVM entries are encountered, set opt.svm_mode so that other
> SVM-specific functionality is triggered.
>
> Remove the `--svm-mode` command-line option, since it's now redundant.
>
> Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxx>

Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>