On 9/10/24 04:18, Keith Busch wrote:
On Mon, Sep 09, 2024 at 07:34:45PM +0800, Changqi Lu wrote:
+static int coroutine_fn GRAPH_RDLOCK
+raw_co_pr_register(BlockDriverState *bs, uint64_t old_key,
+ uint64_t new_key, BlockPrType type,
+ bool ptpl, bool ignore_key)
+{
+ return bdrv_co_pr_register(bs->file->bs, old_key, new_key,
+ type, ptpl, ignore_key);
+}
The nvme parts look fine, but could you help me understand how this all
works? I was looking for something utilizing ioctl's, like
IOC_PR_REGISTER for this one, chained through the file-posix block
driver. Is this only supposed to work with iscsi?
Hi Keith,
IOC_PR_REGISTER family supports PR OUT direction only in Linux kernel,
so the command `blkpr` command (from util-linux since v2.39) supports PR
OUT direction only too.
- In a guest:
* `blkpr` command could test PR OUT commands.
* `sg_persist` command (from sg3-utils) works fine on a SCSI device
* `nvme` command (from nvme-cli) works fine on a NVMe device
- On a host:
* libiscsi supports PR, and LIO/SPDK supports PR from the target side,
tgt supports uncompleted PR(lack of PTPL), so QEMU libiscsi driver works
fine.
* `iscsi-pr` command (from libiscsi-bin since v1.20.0) supports the full
PR family command.
* because of the lack of PR IN commands from linux block layer, so QEMU
posix block driver can't support PR currently. Once this series is
merged into QEMU, I think we have a scenario on posix block PR IN
family, it's a hint to promote it for linux block layer.
* I wrote a user space nvme-of library `libnvmf`
(https://github.com/bytedance/libnvmf), it does not support PR family
command, but I don't think it's difficult to support if necessary.
* As far as I know, several private vendor block driver support PR
family, this QEMU block framework will make the private drivers easy to
integrate.
