Re: [Patch v11 05/10] perf regs: Support x86 eGPRs/SSP sampling

[sashiko-bot@kernel.org]

> Add support for sampling x86 extended GP registers (R16-R31) and the
> shadow stack pointer (SSP) register.
> 
> The original XMM registers space in sample_regs_user/sample_regs_intr is
> reclaimed to represent the eGPRs and SSP when SIMD registers sampling is
> supported with the new SIMD sampling fields in the perf_event_attr
> structure. This necessitates a way to distinguish which register layout
> is used for the sample_regs_user/sample_regs_intr bitmap.
> 
> To address this, a new "abi" argument is added to the helpers
> perf_intr_reg_mask(), perf_user_reg_mask(), and perf_reg_name(). When
> "abi & PERF_SAMPLE_REGS_ABI_SIMD" is true, it indicates the eGPRs and SSP
> layout is represented; otherwise, the legacy XMM registers are
> represented.
> 
> Please note that PERF_SAMPLE_REGS_ABI_SIMD is set by default on platforms
> that support SIMD register sampling, even when no eGPR or SSP register is
> requested (for example, -Iax). As a result, sample_regs_intr and
> sample_regs_usr always use the new GPR layout on platforms with SIMD
> register sampling support.
> 
> The patch only supports eGPRs and SSP sampling, the complete SIMD
> registers sampling would be supported in the next patch.
> 
> Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260914014049.2061519-1-dapeng1.mi@linux.intel.com?part=5