From: Christoph Hellwig Date: Mon, 25 Aug 2025 13:32:49 +0000 (+0200) Subject: nvme: fix PI insert on write X-Git-Tag: nvme-6.17-2025-09-04^0 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=refs%2Fheads%2Fnvme-6.17;p=nvme.git nvme: fix PI insert on write I recently ran into an issue where the PI generated using the block layer integrity code differs from that from a kernel using the PRACT fallback when the block layer integrity code is disabled, and I tracked this down to us using PRACT incorrectly. The NVM Command Set Specification (section 5.33 in 1.2, similar in older versions) specifies the PRACT insert behavior as: Inserted protection information consists of the computed CRC for the protection information format (refer to section 5.3.1) in the Guard field, the LBAT field value in the Application Tag field, the LBST field value in the Storage Tag field, if defined, and the computed reference tag in the Logical Block Reference Tag. Where the computed reference tag is defined as following for type 1 and type 2 using the text below that is duplicated in the respective bullet points: the value of the computed reference tag for the first logical block of the command is the value contained in the Initial Logical Block Reference Tag (ILBRT) or Expected Initial Logical Block Reference Tag (EILBRT) field in the command, and the computed reference tag is incremented for each subsequent logical block. So we need to set ILBRT field, but we currently don't. Interestingly this works fine on my older type 1 formatted SSD, but Qemu trips up on this. We already set ILBRT for Write Same since commit aeb7bb061be5 ("nvme: set the PRACT bit when using Write Zeroes with T10 PI"). To ease this, move the PI type check into nvme_set_ref_tag. Reviewed-by: Martin K. Petersen Signed-off-by: Christoph Hellwig Signed-off-by: Keith Busch --- diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 812c1565114f..6b7493934535 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -903,6 +903,15 @@ static void nvme_set_ref_tag(struct nvme_ns *ns, struct nvme_command *cmnd, u32 upper, lower; u64 ref48; + /* only type1 and type 2 PI formats have a reftag */ + switch (ns->head->pi_type) { + case NVME_NS_DPS_PI_TYPE1: + case NVME_NS_DPS_PI_TYPE2: + break; + default: + return; + } + /* both rw and write zeroes share the same reftag format */ switch (ns->head->guard_type) { case NVME_NVM_NS_16B_GUARD: @@ -942,13 +951,7 @@ static inline blk_status_t nvme_setup_write_zeroes(struct nvme_ns *ns, if (nvme_ns_has_pi(ns->head)) { cmnd->write_zeroes.control |= cpu_to_le16(NVME_RW_PRINFO_PRACT); - - switch (ns->head->pi_type) { - case NVME_NS_DPS_PI_TYPE1: - case NVME_NS_DPS_PI_TYPE2: - nvme_set_ref_tag(ns, cmnd, req); - break; - } + nvme_set_ref_tag(ns, cmnd, req); } return BLK_STS_OK; @@ -1039,6 +1042,7 @@ static inline blk_status_t nvme_setup_rw(struct nvme_ns *ns, if (WARN_ON_ONCE(!nvme_ns_has_pi(ns->head))) return BLK_STS_NOTSUPP; control |= NVME_RW_PRINFO_PRACT; + nvme_set_ref_tag(ns, cmnd, req); } if (bio_integrity_flagged(req->bio, BIP_CHECK_GUARD))