; Sent: Sunday, September 6, 2020 1:06 PM
> > To: Tom Yan ; ebl...@redhat.com;
> > pbonz...@redhat.com; f...@euphon.net; anie...@linux.vnet.ibm.com;
> > kw...@redhat.com; mre...@redhat.com
> > Cc: qemu-devel@nongnu.org; qemu-bl...@nongnu.org
> > Subject: Re: [PATCH v4
t; kw...@redhat.com; mre...@redhat.com
> Cc: qemu-devel@nongnu.org; qemu-bl...@nongnu.org
> Subject: Re: [PATCH v4 2/2] file-posix: add sg_get_max_segments that
> actually works with sg
>
> On Sun, 2020-09-06 at 23:26 +0800, Tom Yan wrote:
> > I don't disagree with your propo
On Sun, 2020-09-06 at 23:26 +0800, Tom Yan wrote:
> I don't disagree with your proposal, but the thing is, do we even need
> another field/limit for case 1? For example, do we *really* need to
> clamp sizes[2] (NBD_INFO_BLOCK_SIZE) in nbd/server.c and
> max_io_sectors (SCSIBlockLimits) in hw/scsi/s
I don't disagree with your proposal, but the thing is, do we even need
another field/limit for case 1? For example, do we *really* need to
clamp sizes[2] (NBD_INFO_BLOCK_SIZE) in nbd/server.c and
max_io_sectors (SCSIBlockLimits) in hw/scsi/scsi-disk.c to to any kind
of "dynamic" limit?
Either way
On Sun, 2020-09-06 at 19:04 +0800, Tom Yan wrote:
> Maybe you want to add some condition for this:
> https://github.com/qemu/qemu/blob/v5.1.0/nbd/server.c#L659
> Or not clamp it at all.
>
> On Sun, 6 Sep 2020 at 18:58, Tom Yan wrote:
> > In commit 867eccfed84f96b54f4a432c510a02c2ce03b430, Levitsk
Maybe you want to add some condition for this:
https://github.com/qemu/qemu/blob/v5.1.0/nbd/server.c#L659
Or not clamp it at all.
On Sun, 6 Sep 2020 at 18:58, Tom Yan wrote:
>
> In commit 867eccfed84f96b54f4a432c510a02c2ce03b430, Levitsky appears
> to have assumed that the only "SCSI Passthrough"
In commit 867eccfed84f96b54f4a432c510a02c2ce03b430, Levitsky appears
to have assumed that the only "SCSI Passthrough" is `-device
scsi-generic`, while the fact is there's also `-device scsi-block`
(passthrough without the sg driver). Unlike `-device scsi-hd`, getting
max_sectors is necessary to it
sg devices have different major/minor than their corresponding
block devices. Using sysfs to get max segments never really worked
for them.
Fortunately the sg driver provides an ioctl to get sg_tablesize,
which is apparently equivalent to max segments.
Signed-off-by: Tom Yan
---
block/file-posi
