| Message ID | 162870796589.2521182.1240403310175570220.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | b93dfa6bda4d4e88e5386490f2b277a26958f9d3 |
| Headers | show |
| Series | [v2] ACPI: NFIT: Fix support for virtual SPA ranges | expand |
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 23d9a09d7060..a3ef6cce644c 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -3021,6 +3021,9 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc, struct acpi_nfit_memory_map *memdev = nfit_memdev->memdev; struct nd_mapping_desc *mapping; + /* range index 0 == unmapped in SPA or invalid-SPA */ + if (memdev->range_index == 0 || spa->range_index == 0) + continue; if (memdev->range_index != spa->range_index) continue; if (count >= ND_MAX_MAPPINGS) {
Fix the NFIT parsing code to treat a 0 index in a SPA Range Structure as a special case and not match Region Mapping Structures that use 0 to indicate that they are not mapped. Without this fix some platform BIOS descriptions of "virtual disk" ranges do not result in the pmem driver attaching to the range. Details: In addition to typical persistent memory ranges, the ACPI NFIT may also convey "virtual" ranges. These ranges are indicated by a UUID in the SPA Range Structure of UUID_VOLATILE_VIRTUAL_DISK, UUID_VOLATILE_VIRTUAL_CD, UUID_PERSISTENT_VIRTUAL_DISK, or UUID_PERSISTENT_VIRTUAL_CD. The critical difference between virtual ranges and UUID_PERSISTENT_MEMORY, is that virtual do not support associations with Region Mapping Structures. For this reason the "index" value of virtual SPA Range Structures is allowed to be 0. If a platform BIOS decides to represent NVDIMMs with disconnected "Region Mapping Structures" (range-index == 0), the kernel may falsely associate them with standalone ranges where the "SPA Range Structure Index" is also zero. When this happens the driver may falsely require labels where "virtual disks" are expected to be label-less. I.e. "label-less" is where the namespace-range == region-range and the pmem driver attaches with no user action to create a namespace. Cc: Jacek Zloch <jacek.zloch@intel.com> Cc: Lukasz Sobieraj <lukasz.sobieraj@intel.com> Cc: "Lee, Chun-Yi" <jlee@suse.com> Cc: <stable@vger.kernel.org> Fixes: c2f32acdf848 ("acpi, nfit: treat virtual ramdisk SPA as pmem region") Reported-by: Krzysztof Rusocki <krzysztof.rusocki@intel.com> Reported-by: Damian Bassa <damian.bassa@intel.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- Changes since v1: - Clarify the changelog (Jeff) - Add a comment about why range_index is checked (Jeff) drivers/acpi/nfit/core.c | 3 +++ 1 file changed, 3 insertions(+)