* [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev
@ 2020-03-31 13:23 Christian Schoenebeck
2020-03-31 15:27 ` Cornelia Huck
2020-04-20 15:42 ` Greg Kurz
0 siblings, 2 replies; 7+ messages in thread
From: Christian Schoenebeck @ 2020-03-31 13:23 UTC (permalink / raw)
To: qemu-devel; +Cc: Greg Kurz
The docs are ambiguous about the difference (or actually their
equality) between options '-virtfs' vs. '-fsdev'. So clarify that
'-virtfs' is actually just a convenience shortcut for its
generalized form '-fsdev' in conjunction with '-device virtio-9p-pci'.
And as we're at it, also be a bit more descriptive what 9pfs is
actually used for.
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
qemu-options.hx | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/qemu-options.hx b/qemu-options.hx
index 962a5ebaa6..fd3830c6cd 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1542,9 +1542,17 @@ SRST
``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly]``
\
``-virtfs synth,mount_tag=mount_tag``
- Define a new filesystem device and expose it to the guest using a
- virtio-9p-device. The general form of a Virtual File system
- pass-through options are:
+ Define a new virtual filesystem device and expose it to the guest using
+ a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain
+ directory on host is made directly accessible by guest as a pass-through
+ file system by using the 9P network protocol for communication between
+ host and guests, if desired even accessible, shared by several guests
+ simultaniously.
+
+ Note that ``-virtfs`` is actually just a convenience shortcut for its
+ generalized form ``-fsdev -device virtio-9p-pci``.
+
+ The general form of pass-through file system options are:
``local``
Accesses to the filesystem are done by QEMU.
--
2.20.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev
2020-03-31 13:23 [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev Christian Schoenebeck
@ 2020-03-31 15:27 ` Cornelia Huck
2020-03-31 15:41 ` Christian Schoenebeck
2020-04-20 15:42 ` Greg Kurz
1 sibling, 1 reply; 7+ messages in thread
From: Cornelia Huck @ 2020-03-31 15:27 UTC (permalink / raw)
To: Christian Schoenebeck; +Cc: qemu-devel, Greg Kurz
On Tue, 31 Mar 2020 15:23:38 +0200
Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> The docs are ambiguous about the difference (or actually their
> equality) between options '-virtfs' vs. '-fsdev'. So clarify that
> '-virtfs' is actually just a convenience shortcut for its
> generalized form '-fsdev' in conjunction with '-device virtio-9p-pci'.
>
> And as we're at it, also be a bit more descriptive what 9pfs is
> actually used for.
>
> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> ---
> qemu-options.hx | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 962a5ebaa6..fd3830c6cd 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -1542,9 +1542,17 @@ SRST
> ``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly]``
> \
> ``-virtfs synth,mount_tag=mount_tag``
> - Define a new filesystem device and expose it to the guest using a
> - virtio-9p-device. The general form of a Virtual File system
> - pass-through options are:
> + Define a new virtual filesystem device and expose it to the guest using
> + a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain
> + directory on host is made directly accessible by guest as a pass-through
> + file system by using the 9P network protocol for communication between
> + host and guests, if desired even accessible, shared by several guests
> + simultaniously.
> +
> + Note that ``-virtfs`` is actually just a convenience shortcut for its
> + generalized form ``-fsdev -device virtio-9p-pci``.
Huh. This prompted me to try this on s390, and it actually creates a
virtio-9p-pci device there as well, not a virtio-9p-ccw device. A bit
surprising; but I don't see 9p used much (if at all) on s390 anyway.
> +
> + The general form of pass-through file system options are:
>
> ``local``
> Accesses to the filesystem are done by QEMU.
Good to see this spelled out:
Acked-by: Cornelia Huck <cohuck@redhat.com>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev
2020-03-31 15:27 ` Cornelia Huck
@ 2020-03-31 15:41 ` Christian Schoenebeck
2020-03-31 16:05 ` Markus Armbruster
0 siblings, 1 reply; 7+ messages in thread
From: Christian Schoenebeck @ 2020-03-31 15:41 UTC (permalink / raw)
To: Cornelia Huck; +Cc: qemu-devel, Greg Kurz
On Dienstag, 31. März 2020 17:27:27 CEST Cornelia Huck wrote:
> > diff --git a/qemu-options.hx b/qemu-options.hx
> > index 962a5ebaa6..fd3830c6cd 100644
> > --- a/qemu-options.hx
> > +++ b/qemu-options.hx
> > @@ -1542,9 +1542,17 @@ SRST
> >
> > ``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag
> > [,writeout=writeout][,readonly]``>
> > \
> >
> > ``-virtfs synth,mount_tag=mount_tag``
> >
> > - Define a new filesystem device and expose it to the guest using a
> > - virtio-9p-device. The general form of a Virtual File system
> > - pass-through options are:
> > + Define a new virtual filesystem device and expose it to the guest
> > using + a virtio-9p-device (a.k.a. 9pfs), which essentially means that
> > a certain + directory on host is made directly accessible by guest as
> > a pass-through + file system by using the 9P network protocol for
> > communication between + host and guests, if desired even accessible,
> > shared by several guests + simultaniously.
> > +
> > + Note that ``-virtfs`` is actually just a convenience shortcut for its
> > + generalized form ``-fsdev -device virtio-9p-pci``.
>
> Huh. This prompted me to try this on s390, and it actually creates a
> virtio-9p-pci device there as well, not a virtio-9p-ccw device. A bit
> surprising; but I don't see 9p used much (if at all) on s390 anyway.
Yeah, "virtio-9p-pci" is currently hard coded in softmmu/vl.c [line 3352]:
https://github.com/qemu/qemu/blob/17083d6d1e0635371418c26b613a6fa68d392f49/softmmu/vl.c#L3352
> > +
> >
> > + The general form of pass-through file system options are:
> > ``local``
> >
> > Accesses to the filesystem are done by QEMU.
>
> Good to see this spelled out:
>
> Acked-by: Cornelia Huck <cohuck@redhat.com>
Best regards,
Christian Schoenebeck
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev
2020-03-31 15:41 ` Christian Schoenebeck
@ 2020-03-31 16:05 ` Markus Armbruster
2020-03-31 16:10 ` Cornelia Huck
0 siblings, 1 reply; 7+ messages in thread
From: Markus Armbruster @ 2020-03-31 16:05 UTC (permalink / raw)
To: Christian Schoenebeck; +Cc: Cornelia Huck, qemu-devel, Greg Kurz
Christian Schoenebeck <qemu_oss@crudebyte.com> writes:
> On Dienstag, 31. März 2020 17:27:27 CEST Cornelia Huck wrote:
>> > diff --git a/qemu-options.hx b/qemu-options.hx
>> > index 962a5ebaa6..fd3830c6cd 100644
>> > --- a/qemu-options.hx
>> > +++ b/qemu-options.hx
>> > @@ -1542,9 +1542,17 @@ SRST
>> >
>> > ``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag
>> > [,writeout=writeout][,readonly]``>
>> > \
>> >
>> > ``-virtfs synth,mount_tag=mount_tag``
>> >
>> > - Define a new filesystem device and expose it to the guest using a
>> > - virtio-9p-device. The general form of a Virtual File system
>> > - pass-through options are:
>> > + Define a new virtual filesystem device and expose it to the guest
>> > using + a virtio-9p-device (a.k.a. 9pfs), which essentially means that
>> > a certain + directory on host is made directly accessible by guest as
>> > a pass-through + file system by using the 9P network protocol for
>> > communication between + host and guests, if desired even accessible,
>> > shared by several guests + simultaniously.
>> > +
>> > + Note that ``-virtfs`` is actually just a convenience shortcut for its
>> > + generalized form ``-fsdev -device virtio-9p-pci``.
>>
>> Huh. This prompted me to try this on s390, and it actually creates a
>> virtio-9p-pci device there as well, not a virtio-9p-ccw device. A bit
>> surprising; but I don't see 9p used much (if at all) on s390 anyway.
>
> Yeah, "virtio-9p-pci" is currently hard coded in softmmu/vl.c [line 3352]:
> https://github.com/qemu/qemu/blob/17083d6d1e0635371418c26b613a6fa68d392f49/softmmu/vl.c#L3352
Should it be "virtio-9p" instead? It's an alias for "virtio-9p-pci",
except for s390x, where it's an alias for "virtio-9p-ccw".
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev
2020-03-31 16:05 ` Markus Armbruster
@ 2020-03-31 16:10 ` Cornelia Huck
2020-04-01 9:08 ` Christian Schoenebeck
0 siblings, 1 reply; 7+ messages in thread
From: Cornelia Huck @ 2020-03-31 16:10 UTC (permalink / raw)
To: Markus Armbruster; +Cc: Christian Schoenebeck, qemu-devel, Greg Kurz
On Tue, 31 Mar 2020 18:05:08 +0200
Markus Armbruster <armbru@redhat.com> wrote:
> Christian Schoenebeck <qemu_oss@crudebyte.com> writes:
>
> > On Dienstag, 31. März 2020 17:27:27 CEST Cornelia Huck wrote:
> >> > diff --git a/qemu-options.hx b/qemu-options.hx
> >> > index 962a5ebaa6..fd3830c6cd 100644
> >> > --- a/qemu-options.hx
> >> > +++ b/qemu-options.hx
> >> > @@ -1542,9 +1542,17 @@ SRST
> >> >
> >> > ``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag
> >> > [,writeout=writeout][,readonly]``>
> >> > \
> >> >
> >> > ``-virtfs synth,mount_tag=mount_tag``
> >> >
> >> > - Define a new filesystem device and expose it to the guest using a
> >> > - virtio-9p-device. The general form of a Virtual File system
> >> > - pass-through options are:
> >> > + Define a new virtual filesystem device and expose it to the guest
> >> > using + a virtio-9p-device (a.k.a. 9pfs), which essentially means that
> >> > a certain + directory on host is made directly accessible by guest as
> >> > a pass-through + file system by using the 9P network protocol for
> >> > communication between + host and guests, if desired even accessible,
> >> > shared by several guests + simultaniously.
> >> > +
> >> > + Note that ``-virtfs`` is actually just a convenience shortcut for its
> >> > + generalized form ``-fsdev -device virtio-9p-pci``.
> >>
> >> Huh. This prompted me to try this on s390, and it actually creates a
> >> virtio-9p-pci device there as well, not a virtio-9p-ccw device. A bit
> >> surprising; but I don't see 9p used much (if at all) on s390 anyway.
> >
> > Yeah, "virtio-9p-pci" is currently hard coded in softmmu/vl.c [line 3352]:
> > https://github.com/qemu/qemu/blob/17083d6d1e0635371418c26b613a6fa68d392f49/softmmu/vl.c#L3352
>
> Should it be "virtio-9p" instead? It's an alias for "virtio-9p-pci",
> except for s390x, where it's an alias for "virtio-9p-ccw".
Seems like a reasonable change (although I'm not sure it matters too
much).
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev
2020-03-31 16:10 ` Cornelia Huck
@ 2020-04-01 9:08 ` Christian Schoenebeck
0 siblings, 0 replies; 7+ messages in thread
From: Christian Schoenebeck @ 2020-04-01 9:08 UTC (permalink / raw)
To: qemu-devel; +Cc: Cornelia Huck, Markus Armbruster, Greg Kurz
On Dienstag, 31. März 2020 18:10:33 CEST Cornelia Huck wrote:
> > >> Huh. This prompted me to try this on s390, and it actually creates a
> > >> virtio-9p-pci device there as well, not a virtio-9p-ccw device. A bit
> > >> surprising; but I don't see 9p used much (if at all) on s390 anyway.
> > >
> > > Yeah, "virtio-9p-pci" is currently hard coded in softmmu/vl.c [line
> > > 3352]:
> > > https://github.com/qemu/qemu/blob/17083d6d1e0635371418c26b613a6fa68d392f
> > > 49/softmmu/vl.c#L3352>
> > Should it be "virtio-9p" instead? It's an alias for "virtio-9p-pci",
> > except for s390x, where it's an alias for "virtio-9p-ccw".
>
> Seems like a reasonable change (although I'm not sure it matters too
> much).
It would be a minor change it seems, and yes there seems to be a virtio-9p-ccw
implementation, however as long as nobody complains I leave it untouched for
now. Especially since I have no idea about the s390 architecture, nor testing
it.
Best regards,
Christian Schoenebeck
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev
2020-03-31 13:23 [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev Christian Schoenebeck
2020-03-31 15:27 ` Cornelia Huck
@ 2020-04-20 15:42 ` Greg Kurz
1 sibling, 0 replies; 7+ messages in thread
From: Greg Kurz @ 2020-04-20 15:42 UTC (permalink / raw)
To: Christian Schoenebeck; +Cc: qemu-devel
On Tue, 31 Mar 2020 15:23:38 +0200
Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> The docs are ambiguous about the difference (or actually their
> equality) between options '-virtfs' vs. '-fsdev'. So clarify that
> '-virtfs' is actually just a convenience shortcut for its
> generalized form '-fsdev' in conjunction with '-device virtio-9p-pci'.
>
> And as we're at it, also be a bit more descriptive what 9pfs is
> actually used for.
>
> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> ---
Applied to 9p-next.
> qemu-options.hx | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 962a5ebaa6..fd3830c6cd 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -1542,9 +1542,17 @@ SRST
> ``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly]``
> \
> ``-virtfs synth,mount_tag=mount_tag``
> - Define a new filesystem device and expose it to the guest using a
> - virtio-9p-device. The general form of a Virtual File system
> - pass-through options are:
> + Define a new virtual filesystem device and expose it to the guest using
> + a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain
> + directory on host is made directly accessible by guest as a pass-through
> + file system by using the 9P network protocol for communication between
> + host and guests, if desired even accessible, shared by several guests
> + simultaniously.
> +
> + Note that ``-virtfs`` is actually just a convenience shortcut for its
> + generalized form ``-fsdev -device virtio-9p-pci``.
> +
> + The general form of pass-through file system options are:
>
> ``local``
> Accesses to the filesystem are done by QEMU.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2020-04-20 15:43 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2020-03-31 13:23 [PATCH] qemu-options.hx: 9p: clarify -virtfs vs. -fsdev Christian Schoenebeck
2020-03-31 15:27 ` Cornelia Huck
2020-03-31 15:41 ` Christian Schoenebeck
2020-03-31 16:05 ` Markus Armbruster
2020-03-31 16:10 ` Cornelia Huck
2020-04-01 9:08 ` Christian Schoenebeck
2020-04-20 15:42 ` Greg Kurz
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