Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [High] cxl: cxl_configure_dcd() falsely fails overlap check and double-counts total DPA capacity --
commit e491a6175f0241ed507a397807a28860fd54aadf Author: Ira Weiny <[email protected]> cxl/mem: Read dynamic capacity configuration from the device This commit implements Dynamic Capacity (DC) mailbox commands to read and store DCD configuration information. It validates the first dynamic capacity partition and configures it as dynamic ram, disabling DCD if the configuration is invalid. > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index b3419df586b9c..def26c490dfe4 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c [ ... ] > @@ -643,6 +643,53 @@ int cxl_mem_dpa_fetch(struct cxl_memdev_state *mds, > struct cxl_dpa_info *info) > } > EXPORT_SYMBOL_NS_GPL(cxl_mem_dpa_fetch, "CXL"); > > +int cxl_configure_dcd(struct cxl_memdev_state *mds, struct cxl_dpa_info > *info) > +{ [ ... ] > + if (dc_info.start < info->size) { > + dev_err(dev, > + "DC partition 0 base %#llx overlaps static capacity > ending at %#llx\n", > + dc_info.start, info->size); > + return -EINVAL; > + } [Severity: High] Will this overlap check unconditionally fail for any valid DCD configuration? Earlier in the execution flow, cxl_mem_dpa_fetch() initializes info->size to the total DPA capacity (including both static and dynamic capacity): info->size = mds->total_bytes; Since the DC partition is placed within this total space, dc_info.start will always be strictly less than the total info->size. This appears to cause a regression where cxl_pci_probe() silently disables DCD support. [ ... ] > + if (check_add_overflow(info->size, dc_info.size, &total)) { > + dev_err(dev, > + "DC partition 0 size %#llx overflows DPA space ending > at %#llx\n", > + dc_info.size, info->size); > + return -EINVAL; > + } > + > + info->size = total; [Severity: High] If the above overlap check were bypassed, would this assignment double-count the dynamic capacity size? Since info->size already includes the dynamic capacity initialized from cxl_mem_dpa_fetch(), adding dc_info.size again to the total could cause cxl_dpa_setup() to allocate a dpa_res root resource larger than the physical device limit. -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=2
