drm/xe/vf: Catch all unexpected register reads

While we can only mimic read32 for a few GT registers for which
the PF shared the values, we shouldn't avoid calling helper code
if we try to access non-GT register, as then we miss to trigger
a debug warning. For cases where sriov_vf_gt was not set, just
use primary_gt instead.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250311135726.1998-3-michal.wajdeczko@intel.com

drivers/gpu/drm/xe/xe_mmio.c

@@ -204,8 +204,9 @@ void xe_mmio_write32(struct xe_mmio *mmio, struct xe_reg reg, u32 val)
 
 	trace_xe_reg_rw(mmio, true, addr, val, sizeof(val));
 
-	if (!reg.vf && mmio->sriov_vf_gt)
-		xe_gt_sriov_vf_write32(mmio->sriov_vf_gt, reg, val);
+	if (!reg.vf && IS_SRIOV_VF(mmio->tile->xe))
+		xe_gt_sriov_vf_write32(mmio->sriov_vf_gt ?:
+				       mmio->tile->primary_gt, reg, val);
 	else
 		writel(val, mmio->regs + addr);
 }
@@ -218,8 +219,9 @@ u32 xe_mmio_read32(struct xe_mmio *mmio, struct xe_reg reg)
 	/* Wa_15015404425 */
 	mmio_flush_pending_writes(mmio);
 
-	if (!reg.vf && mmio->sriov_vf_gt)
-		val = xe_gt_sriov_vf_read32(mmio->sriov_vf_gt, reg);
+	if (!reg.vf && IS_SRIOV_VF(mmio->tile->xe))
+		val = xe_gt_sriov_vf_read32(mmio->sriov_vf_gt ?:
+					    mmio->tile->primary_gt, reg);
 	else
 		val = readl(mmio->regs + addr);