search for: hotunplug

Changes in v2: - Remove code duplication in tcm_vhost_{hotplug,hotunplug} - Fix racing of vs_events_nr - Add flush fix patch to this series Asias He (6): tcm_vhost: Add missed lock in vhost_scsi_clear_endpoint() tcm_vhost: Introduce tcm_vhost_check_feature() tcm_vhost: Introduce tcm_vhost_check_endpoint() tcm_vhost: Fix vs->vs_endpoint checking in vhost_scsi...

Changes in v2: - Remove code duplication in tcm_vhost_{hotplug,hotunplug} - Fix racing of vs_events_nr - Add flush fix patch to this series Asias He (6): tcm_vhost: Add missed lock in vhost_scsi_clear_endpoint() tcm_vhost: Introduce tcm_vhost_check_feature() tcm_vhost: Introduce tcm_vhost_check_endpoint() tcm_vhost: Fix vs->vs_endpoint checking in vhost_scsi...

...e careful wrt > > > serialization, especially if we want to reuse the ccw structure as > > > well, for example. Nothing complicated, I'd just need some free time to > > > do it :) > > > > > > The more likely reason for get_config to fail is a device hotunplug, > > > however. We'll get a seperate notification about that (via machine > > > check + channel report), but it would be nice if we could stop poking > > > the device immediately, as there's no use trying to do something with > > > it anymore. > >...

...e careful wrt > > > serialization, especially if we want to reuse the ccw structure as > > > well, for example. Nothing complicated, I'd just need some free time to > > > do it :) > > > > > > The more likely reason for get_config to fail is a device hotunplug, > > > however. We'll get a seperate notification about that (via machine > > > check + channel report), but it would be nice if we could stop poking > > > the device immediately, as there's no use trying to do something with > > > it anymore. > >...

In commit 365a7150094 ([SCSI] virtio-scsi: hotplug support for virtio-scsi), hotplug support is added to virtio-scsi. This patch adds hotplug and hotunplug support to tcm_vhost. You can create or delate a LUN in targetcli to hotplug or hotplug a LUN in guest. Signed-off-by: Asias He <asias at redhat.com> --- drivers/vhost/tcm_vhost.c | 171 ++++++++++++++++++++++++++++++++++++++++++++-- drivers/vhost/tcm_vhost.h | 9 +++ 2 files changed, 17...

In commit 365a7150094 ([SCSI] virtio-scsi: hotplug support for virtio-scsi), hotplug support is added to virtio-scsi. This patch adds hotplug and hotunplug support to tcm_vhost. You can create or delate a LUN in targetcli to hotplug or hotplug a LUN in guest. Signed-off-by: Asias He <asias at redhat.com> --- drivers/vhost/tcm_vhost.c | 171 ++++++++++++++++++++++++++++++++++++++++++++-- drivers/vhost/tcm_vhost.h | 9 +++ 2 files changed, 17...

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1121540 When we try to hot-unplugging a busy virtio-rng device, the device can't be removed. And the reading process in guest gets stuck. Those two patches fixed this issue by completing have_data completion and preventing invalid reading. Thanks for the help of Amit. Cc: stable at vger.kernel.org V2: reset data_avail (Amit) adjust

...; we need it to be under 2G. And we need to be more careful wrt > serialization, especially if we want to reuse the ccw structure as > well, for example. Nothing complicated, I'd just need some free time to > do it :) > > The more likely reason for get_config to fail is a device hotunplug, > however. We'll get a seperate notification about that (via machine > check + channel report), but it would be nice if we could stop poking > the device immediately, as there's no use trying to do something with > it anymore. Normally, hotunplug requires guest cooperation. IO...

...; we need it to be under 2G. And we need to be more careful wrt > serialization, especially if we want to reuse the ccw structure as > well, for example. Nothing complicated, I'd just need some free time to > do it :) > > The more likely reason for get_config to fail is a device hotunplug, > however. We'll get a seperate notification about that (via machine > check + channel report), but it would be nice if we could stop poking > the device immediately, as there's no use trying to do something with > it anymore. Normally, hotunplug requires guest cooperation. IO...

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1121540 When we try to hot-unplugging a busy virtio-rng device, the device can't be removed. And the reading process in guest gets stuck. Those two patches fixed this issue by completing have_data completion and preventing invalid reading. Thanks for the help of Amit. Cc: stable at vger.kernel.org V2: reset data_avail (Amit) adjust

Asias He (2): tcm_vhost: Introduce tcm_vhost_check_feature() tcm_vhost: Add hotplug/hotunplug support drivers/vhost/tcm_vhost.c | 224 ++++++++++++++++++++++++++++++++++++++++++++-- drivers/vhost/tcm_vhost.h | 10 +++ 2 files changed, 229 insertions(+), 5 deletions(-) -- 1.8.1.4

Asias He (2): tcm_vhost: Introduce tcm_vhost_check_feature() tcm_vhost: Add hotplug/hotunplug support drivers/vhost/tcm_vhost.c | 224 ++++++++++++++++++++++++++++++++++++++++++++-- drivers/vhost/tcm_vhost.h | 10 +++ 2 files changed, 229 insertions(+), 5 deletions(-) -- 1.8.1.4

When I hotunplug a busy virtio-rng device or try to access hwrng attributes in non-smp guest, it gets stuck. My hotplug tests: | test 0: | hotunplug rng device from qemu monitor | | test 1: | guest) # dd if=/dev/hwrng of=/dev/null & | hotunplug rng device from qemu monitor | | test 2: | guest) # dd if...

When I hotunplug a busy virtio-rng device or try to access hwrng attributes in non-smp guest, it gets stuck. My hotplug tests: | test 0: | hotunplug rng device from qemu monitor | | test 1: | guest) # dd if=/dev/hwrng of=/dev/null & | hotunplug rng device from qemu monitor | | test 2: | guest) # dd if...

...; Yes, if the scan is over a single pmd then caching it makes sense. > > Quite frankly an easier an better solution is to remove the pagemap > lookup as HMM user abide by mmu notifier it means we will not make > use or dereference the struct page so that we are safe from any > racing hotunplug of dax memory (as long as device driver using hmm > do not have a bug). Yes, as long as the driver remove is synchronized against HMM operations via another mechanism then there is no need to take pagemap references. Can you briefly describe what that other mechanism is?

There's currently a big lock around everything, and it means that we can't query sysfs (eg /sys/devices/virtual/misc/hw_random/rng_current) while the rng is reading. This is a real problem when the rng is slow, or blocked (eg. virtio_rng with qemu's default /dev/random backend) This doesn't help (it leaves the current lock untouched), just adds a lock to protect the read function

This hotplug state will be used to remove a device without the guest cooperation. Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> --- hw/acpi_piix4.c | 5 +++++ hw/pci.h | 1 + 2 files changed, 6 insertions(+), 0 deletions(-) diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c index 585da4e..dfd5a9d 100644 --- a/hw/acpi_piix4.c +++ b/hw/acpi_piix4.c @@ -587,6 +587,11 @@

...2G. And we need to be more careful wrt > > serialization, especially if we want to reuse the ccw structure as > > well, for example. Nothing complicated, I'd just need some free time to > > do it :) > > > > The more likely reason for get_config to fail is a device hotunplug, > > however. We'll get a seperate notification about that (via machine > > check + channel report), but it would be nice if we could stop poking > > the device immediately, as there's no use trying to do something with > > it anymore. > > Normally, hotunplug...

...2G. And we need to be more careful wrt > > serialization, especially if we want to reuse the ccw structure as > > well, for example. Nothing complicated, I'd just need some free time to > > do it :) > > > > The more likely reason for get_config to fail is a device hotunplug, > > however. We'll get a seperate notification about that (via machine > > check + channel report), but it would be nice if we could stop poking > > the device immediately, as there's no use trying to do something with > > it anymore. > > Normally, hotunplug...

Asias He (4): tcm_vhost: Refactor the lock nesting rule tcm_vhost: Add hotplug/hotunplug support tcm_vhost: Add ioctl to get and set events missed flag tcm_vhost: Enable VIRTIO_SCSI_F_HOTPLUG drivers/vhost/tcm_vhost.c | 262 +++++++++++++++++++++++++++++++++++++++++++--- drivers/vhost/tcm_vhost.h | 13 +++ 2 files changed, 259 insertions(+), 16 deletions(-) -- 1.8.1.4