Re: [Xen-devel] [PATCH 1/2] xen: wrap xenbus on xenfs with COMPAT option
On 01/12/15 13:45, Doug Goldstein wrote: > On 12/1/15 4:44 AM, David Vrabel wrote: >> On 01/12/15 10:42, David Vrabel wrote: >>> On 30/11/15 21:35, Doug Goldstein wrote: Since Xen 4.6.0, using xenbus via xenfs (/proc/xen/xenbus) is deprecated and /dev/xen/xenbus via pvops is used instead. This is an effort to eventually drop this interface after a reasonable amount of time. >>> >>> I would prefer the ... /proc/xen/evtchn files to be >> >> I meant /proc/xen/privcmd here. >> >> David >> > > I can look into that. I do have a few questions, some of which are out > of scope from the original patch. > > Would it be preferable to just remove "xenbus" from the xenfs > filesystem? Ever since Linux 3.14 even if you are running a version of > Xen earlier than 4.6 you will not be able to have a disaggregated > xenstore (which is the xenbus consumer) due to the addition of F_ATOMIC_POS. If /proc/xen/xenbus is made a symlink then older Xen toolstacks will work again. > Is it safe for a kernel virtual filesystem to provide a symlink outside > of itself where the destination can't be verified? Yes. The symlink target is just a string containing a path. > Since the /proc/xen mount point has been marked as COMPAT for nearly 6 > years would the eventual goal be to move xenfs to somewhere like > /sys/hypervisor given that most of the virtual filesystems are mounted > under /sys now days? No. The information might move to /sys/hypervisor (or elsewhere) but xenfs will always be mounted in /proc/xen (or not mounted at all). David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Xen-devel] [PATCH 1/2] xen: wrap xenbus on xenfs with COMPAT option
On 12/1/15 4:44 AM, David Vrabel wrote: > On 01/12/15 10:42, David Vrabel wrote: >> On 30/11/15 21:35, Doug Goldstein wrote: >>> Since Xen 4.6.0, using xenbus via xenfs (/proc/xen/xenbus) is deprecated >>> and /dev/xen/xenbus via pvops is used instead. This is an effort to >>> eventually drop this interface after a reasonable amount of time. >> >> I would prefer the ... /proc/xen/evtchn files to be > > I meant /proc/xen/privcmd here. > > David > I can look into that. I do have a few questions, some of which are out of scope from the original patch. Would it be preferable to just remove "xenbus" from the xenfs filesystem? Ever since Linux 3.14 even if you are running a version of Xen earlier than 4.6 you will not be able to have a disaggregated xenstore (which is the xenbus consumer) due to the addition of F_ATOMIC_POS. Is it safe for a kernel virtual filesystem to provide a symlink outside of itself where the destination can't be verified? Its possible this already exists and I just don't know off any cases off the top of my head. Since the /proc/xen mount point has been marked as COMPAT for nearly 6 years would the eventual goal be to move xenfs to somewhere like /sys/hypervisor given that most of the virtual filesystems are mounted under /sys now days? -- Doug Goldstein signature.asc Description: OpenPGP digital signature
Re: [Xen-devel] [PATCH 1/2] xen: wrap xenbus on xenfs with COMPAT option
On 01/12/15 10:42, David Vrabel wrote: > On 30/11/15 21:35, Doug Goldstein wrote: >> Since Xen 4.6.0, using xenbus via xenfs (/proc/xen/xenbus) is deprecated >> and /dev/xen/xenbus via pvops is used instead. This is an effort to >> eventually drop this interface after a reasonable amount of time. > > I would prefer the ... /proc/xen/evtchn files to be I meant /proc/xen/privcmd here. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Xen-devel] [PATCH 1/2] xen: wrap xenbus on xenfs with COMPAT option
On 30/11/15 21:35, Doug Goldstein wrote: > Since Xen 4.6.0, using xenbus via xenfs (/proc/xen/xenbus) is deprecated > and /dev/xen/xenbus via pvops is used instead. This is an effort to > eventually drop this interface after a reasonable amount of time. I would prefer the /proc/xen/xenbus and /proc/xen/evtchn files to be replaced with symlinks to the corresponding /dev/xen/ devices. Then I see no need to ever remove them, thus avoiding the need for yet another config option. I did briefly look at this and it seemed possible but didn't get as far as actually trying to change it. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Xen-devel] [PATCH 1/2] xen: wrap xenbus on xenfs with COMPAT option
On 30/11/15 21:35, Doug Goldstein wrote: > Since Xen 4.6.0, using xenbus via xenfs (/proc/xen/xenbus) is deprecated > and /dev/xen/xenbus via pvops is used instead. This is an effort to > eventually drop this interface after a reasonable amount of time. I would prefer the /proc/xen/xenbus and /proc/xen/evtchn files to be replaced with symlinks to the corresponding /dev/xen/ devices. Then I see no need to ever remove them, thus avoiding the need for yet another config option. I did briefly look at this and it seemed possible but didn't get as far as actually trying to change it. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Xen-devel] [PATCH 1/2] xen: wrap xenbus on xenfs with COMPAT option
On 01/12/15 10:42, David Vrabel wrote: > On 30/11/15 21:35, Doug Goldstein wrote: >> Since Xen 4.6.0, using xenbus via xenfs (/proc/xen/xenbus) is deprecated >> and /dev/xen/xenbus via pvops is used instead. This is an effort to >> eventually drop this interface after a reasonable amount of time. > > I would prefer the ... /proc/xen/evtchn files to be I meant /proc/xen/privcmd here. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Xen-devel] [PATCH 1/2] xen: wrap xenbus on xenfs with COMPAT option
On 01/12/15 13:45, Doug Goldstein wrote: > On 12/1/15 4:44 AM, David Vrabel wrote: >> On 01/12/15 10:42, David Vrabel wrote: >>> On 30/11/15 21:35, Doug Goldstein wrote: Since Xen 4.6.0, using xenbus via xenfs (/proc/xen/xenbus) is deprecated and /dev/xen/xenbus via pvops is used instead. This is an effort to eventually drop this interface after a reasonable amount of time. >>> >>> I would prefer the ... /proc/xen/evtchn files to be >> >> I meant /proc/xen/privcmd here. >> >> David >> > > I can look into that. I do have a few questions, some of which are out > of scope from the original patch. > > Would it be preferable to just remove "xenbus" from the xenfs > filesystem? Ever since Linux 3.14 even if you are running a version of > Xen earlier than 4.6 you will not be able to have a disaggregated > xenstore (which is the xenbus consumer) due to the addition of F_ATOMIC_POS. If /proc/xen/xenbus is made a symlink then older Xen toolstacks will work again. > Is it safe for a kernel virtual filesystem to provide a symlink outside > of itself where the destination can't be verified? Yes. The symlink target is just a string containing a path. > Since the /proc/xen mount point has been marked as COMPAT for nearly 6 > years would the eventual goal be to move xenfs to somewhere like > /sys/hypervisor given that most of the virtual filesystems are mounted > under /sys now days? No. The information might move to /sys/hypervisor (or elsewhere) but xenfs will always be mounted in /proc/xen (or not mounted at all). David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Xen-devel] [PATCH 1/2] xen: wrap xenbus on xenfs with COMPAT option
On 12/1/15 4:44 AM, David Vrabel wrote: > On 01/12/15 10:42, David Vrabel wrote: >> On 30/11/15 21:35, Doug Goldstein wrote: >>> Since Xen 4.6.0, using xenbus via xenfs (/proc/xen/xenbus) is deprecated >>> and /dev/xen/xenbus via pvops is used instead. This is an effort to >>> eventually drop this interface after a reasonable amount of time. >> >> I would prefer the ... /proc/xen/evtchn files to be > > I meant /proc/xen/privcmd here. > > David > I can look into that. I do have a few questions, some of which are out of scope from the original patch. Would it be preferable to just remove "xenbus" from the xenfs filesystem? Ever since Linux 3.14 even if you are running a version of Xen earlier than 4.6 you will not be able to have a disaggregated xenstore (which is the xenbus consumer) due to the addition of F_ATOMIC_POS. Is it safe for a kernel virtual filesystem to provide a symlink outside of itself where the destination can't be verified? Its possible this already exists and I just don't know off any cases off the top of my head. Since the /proc/xen mount point has been marked as COMPAT for nearly 6 years would the eventual goal be to move xenfs to somewhere like /sys/hypervisor given that most of the virtual filesystems are mounted under /sys now days? -- Doug Goldstein signature.asc Description: OpenPGP digital signature
