Re: [PATCH v9 2/2] lib/intel_device_info: Query runtime xe device graphics versions

["Vodapalli, Ravi Kumar" <ravi.kumar.vodapalli@intel.com>]

On 12/17/2025 10:04 AM, Xin Wang wrote:
> For platforms with graphics_ver >= 20, query the runtime xe device ver
> instead of relying solely on hardcoded values from the PCI device table.
> This enables accurate IP minor version (graphics_rel) detection for
> platforms like Xe2 where different steppings have different IP versions.
>
> Implementation details:
> - Use weak symbol linkage for xe_ipver_cache_lookup() to handle static
>    library compilation (libigt_chipset.a, libigt_device_scan.a) without
>    xe_query.c dependencies which are used for i915 tools (i915_perf and
>    intel_gpu_top)
> - Provide a weak stub that returns NULL when xe_query is not linked
> - For Gen20+ platforms, prefer runtime xe device versions over static data
> - Fall back to PCI table if xe device info is unavailable
> - Reset cache on query failure to allow retry
>
> Remove hardcoded graphics_rel from static table entries for xe devices
> as they will be populated at runtime from GMD_ID.
>
> This unifies device info handling between i915 and xe drivers, enabling:
> - Platform-specific workarounds based on accurate IP versions
> - Consistent device info API across both drivers
>
> Signed-off-by: Xin Wang <x.wang@intel.com>
Reviewed-by: Ravi Kumar V <ravi.kumar.vodapalli@intel.com>

Regards,
Ravi Kumar V
> ---
>   lib/intel_device_info.c | 26 +++++++++++++++++++++++---
>   1 file changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/lib/intel_device_info.c b/lib/intel_device_info.c
> index 20147479a..3bc20ab68 100644
> --- a/lib/intel_device_info.c
> +++ b/lib/intel_device_info.c
> @@ -3,6 +3,16 @@
>   #include "i915_pciids_local.h"
>   
>   #include <strings.h> /* ffs() */
> +#include <stddef.h>
> +#include <string.h>
> +
> +/* Weak symbol stub - will be overridden if xe_query.c is linked */
> +struct xe_device_ipver *xe_ipver_cache_lookup(uint32_t devid) __attribute__((weak));
> +
> +struct xe_device_ipver *xe_ipver_cache_lookup(uint32_t devid)
> +{
> +	return NULL;
> +}
>   
>   static const struct intel_device_info intel_generic_info = {
>   	.graphics_ver = 0,
> @@ -505,7 +515,6 @@ static const struct intel_device_info intel_pontevecchio_info = {
>   
>   static const struct intel_device_info intel_lunarlake_info = {
>   	.graphics_ver = 20,
> -	.graphics_rel = 4,
>   	.display_ver = 20,
>   	.has_4tile = true,
>   	.has_flatccs = true,
> @@ -517,7 +526,6 @@ static const struct intel_device_info intel_lunarlake_info = {
>   
>   static const struct intel_device_info intel_battlemage_info = {
>   	.graphics_ver = 20,
> -	.graphics_rel = 1,
>   	.display_ver = 14,
>   	.has_4tile = true,
>   	.has_flatccs = true,
> @@ -529,7 +537,6 @@ static const struct intel_device_info intel_battlemage_info = {
>   
>   static const struct intel_device_info intel_pantherlake_info = {
>   	.graphics_ver = 30,
> -	.graphics_rel = 0,
>   	.display_ver = 30,
>   	.has_4tile = true,
>   	.has_flatccs = true,
> @@ -700,6 +707,8 @@ const struct intel_device_info *intel_get_device_info(uint16_t devid)
>   {
>   	static __thread const struct intel_device_info *cache = &intel_generic_info;
>   	static __thread uint16_t cached_devid;
> +	static __thread struct intel_device_info xe_dev_info;
> +	struct xe_device_ipver *ipver;
>   	int i;
>   
>   	if (cached_devid == devid)
> @@ -714,6 +723,17 @@ const struct intel_device_info *intel_get_device_info(uint16_t devid)
>   	cached_devid = devid;
>   	cache = (void *)intel_device_match[i].match_data;
>   
> +	if (cache->graphics_ver >= 20) {
> +		ipver = xe_ipver_cache_lookup(devid);
> +		if (ipver && ipver->devid == devid) {
> +			memcpy(&xe_dev_info, cache, sizeof(struct intel_device_info));
> +			xe_dev_info.graphics_ver = ipver->graphics_ver;
> +			xe_dev_info.graphics_rel = ipver->graphics_rel;
> +			cache = &xe_dev_info;
> +		} else {
> +			cached_devid = 0;
> +		}
> +	}
>   out:
>   	return cache;
>   }