Re: [PATCH v4 3/7] block: add max_hw_transfer to BlockLimits

2021-06-09 Thread Maxim Levitsky
On Tue, 2021-06-08 at 15:16 +0200, Paolo Bonzini wrote: > For block host devices, I/O can happen through either the kernel file > descriptor I/O system calls (preadv/pwritev, io_submit, io_uring) > or the SCSI passthrough ioctl SG_IO. > > In the latter case, the size of each transfer can be

Re: [PATCH v4 3/7] block: add max_hw_transfer to BlockLimits

2021-06-08 Thread Eric Blake
On Tue, Jun 08, 2021 at 03:16:30PM +0200, Paolo Bonzini wrote: > For block host devices, I/O can happen through either the kernel file > descriptor I/O system calls (preadv/pwritev, io_submit, io_uring) > or the SCSI passthrough ioctl SG_IO. > > In the latter case, the size of each transfer can

[PATCH v4 3/7] block: add max_hw_transfer to BlockLimits

2021-06-08 Thread Paolo Bonzini
For block host devices, I/O can happen through either the kernel file descriptor I/O system calls (preadv/pwritev, io_submit, io_uring) or the SCSI passthrough ioctl SG_IO. In the latter case, the size of each transfer can be limited by the HBA, while for file descriptor I/O the kernel is able to