similar to: Re: [PATCH v3 0/6] launch: direct: Disable qemu locking when opening drives readonly.

On Wed, Sep 13, 2017 at 12:40:29PM +0300, Roman Kagan wrote: > On Wed, Sep 13, 2017 at 09:47:52AM +0100, Richard W.M. Jones wrote: > > On Wed, Sep 13, 2017 at 11:25:32AM +0300, Roman Kagan wrote: > > > On Tue, Sep 12, 2017 at 06:04:18PM +0100, Richard W.M. Jones wrote: > > > > v2 -> v3: > > > > > > > > - I addressed everything that Pino

On Wed, Sep 13, 2017 at 11:25:32AM +0300, Roman Kagan wrote: > On Tue, Sep 12, 2017 at 06:04:18PM +0100, Richard W.M. Jones wrote: > > v2 -> v3: > > > > - I addressed everything that Pino mentioned last time. > > > > - It's tricky to get a stable run when multiple copies of qemu are > > involved, because the same cache files get overwritten by

On Wed, Sep 06, 2017 at 10:41:24AM +0300, Roman Kagan wrote: > On Tue, Sep 05, 2017 at 03:55:08PM +0100, Richard W.M. Jones wrote: > > Since qemu 2.10, qemu locks all drives even when they are opened > > readonly. This disables this locking in this safe case. > > > > Incomplete fix for > > https://bugzilla.redhat.com/show_bug.cgi?id=1417306 > > --- >

--- lib/launch-direct.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/lib/launch-direct.c b/lib/launch-direct.c index 9f85013f9..00cb25077 100644 --- a/lib/launch-direct.c +++ b/lib/launch-direct.c @@ -66,6 +66,7 @@ struct backend_direct_data { pid_t recoverypid; /* Recovery process PID. */ struct version qemu_version; /* qemu version (0 if

On Tuesday, 12 September 2017 14:29:16 CEST Richard W.M. Jones wrote: > @@ -255,11 +256,13 @@ add_drive_standard_params (guestfs_h *g, struct backend_direct_data *data, > } > else { > /* Writable qcow2 overlay on top of read-only drive. */ > - append_list_format ("file=%s", drv->overlay); > + append_list_format ("file.file.filename=%s",

Since qemu 2.10, qemu locks all drives even when they are opened readonly. This disables this locking in this safe case. Incomplete fix for https://bugzilla.redhat.com/show_bug.cgi?id=1417306 --- lib/launch-direct.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/launch-direct.c b/lib/launch-direct.c index 3b848165c..e5465539d 100644 --- a/lib/launch-direct.c +++

On Tuesday, 5 September 2017 16:55:08 CEST Richard W.M. Jones wrote: > Since qemu 2.10, qemu locks all drives even when they are opened > readonly. This disables this locking in this safe case. > > Incomplete fix for > https://bugzilla.redhat.com/show_bug.cgi?id=1417306 > --- I guess that, according to the other message in this thread, the commit message will be amended to use

Incomplete fix for https://bugzilla.redhat.com/show_bug.cgi?id=1417306 The full fix is waiting for a libvirt change, but this can still go upstream. Rich.

v2 -> v3: - I addressed everything that Pino mentioned last time. - It's tricky to get a stable run when multiple copies of qemu are involved, because the same cache files get overwritten by parallel libguestfs. So I changed the names of the cache files to include the qemu binary key (size, mtime), which removes this conflict. This is in new patch 4/6. Rich.

Patches 1-4 are almost the same as they are when previously posted here: https://www.redhat.com/archives/libguestfs/2017-September/msg00039.html Patch 5 actually uses the mandatory locking test to turn off locking in the narrow case where a drive is opened readonly, and then only for the drive being inspected. Passes ordinary tests (‘check-direct’ and ‘check-valgrind-direct’). Rich.

Ancient qemu 1.5 (in RHEL 7) does not understand the file.file.filename= and file.driver= parameters. Go back to using the old-style file= and format= parameters when we're not trying to set the file.backing.file.locking=off parameter. Fixes commit 9fe592808ccfd9ed184b88ca9c6cad2e1798dee3. Thanks: Yongkui Guo, Václav Kadlčík. --- lib/launch-direct.c | 31 +++++++++++++++++++++---------- 1

QEMU does not accept options unrecognized by the block driver in use. Disable locking only for read-only disks that are file-backed, as that's the only block driver it is supported with. Signed-off-by: Lars Seipel <ls@slrz.net> --- lib/launch-direct.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/lib/launch-direct.c b/lib/launch-direct.c index

From: "Richard W.M. Jones" <rjones@redhat.com> --- src/launch-direct.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/launch-direct.c b/src/launch-direct.c index f06bb23..58e4b1a 100644 --- a/src/launch-direct.c +++ b/src/launch-direct.c @@ -328,6 +328,13 @@ launch_direct (guestfs_h *g, void *datav, const char *arg) ADD_CMDLINE (VIRTIO_BLK

--- src/launch-direct.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/src/launch-direct.c b/src/launch-direct.c index 6eaee63..c091732 100644 --- a/src/launch-direct.c +++ b/src/launch-direct.c @@ -491,7 +491,14 @@ launch_direct (guestfs_h *g, void *datav, const char *arg) */ ADD_CMDLINE ("-no-hpet"); #endif - ADD_CMDLINE

Dr. David Gilbert pointed out to me that the first line of the qemu -help output includes the qemu version, so we don't need to run qemu -version at all. This saves about 0.04s on the launch time when using the direct backend. --- src/launch-direct.c | 54 +++++++++++++++++++---------------------------------- 1 file changed, 19 insertions(+), 35 deletions(-) diff --git a/src/launch-direct.c

On Wed, 2016-03-09 at 20:04 +0300, Roman Kagan wrote: > On Wed, Mar 09, 2016 at 05:41:39PM +0200, Michael S. Tsirkin wrote: > > On Wed, Mar 09, 2016 at 05:28:54PM +0300, Roman Kagan wrote: > > > For (1) I've been trying to make a point that skipping clean > > > pages is > > > much more likely to result in noticable benefit than free pages > > >

On Wed, Mar 09, 2016 at 08:04:39PM +0300, Roman Kagan wrote: > On Wed, Mar 09, 2016 at 05:41:39PM +0200, Michael S. Tsirkin wrote: > > On Wed, Mar 09, 2016 at 05:28:54PM +0300, Roman Kagan wrote: > > > For (1) I've been trying to make a point that skipping clean pages is > > > much more likely to result in noticable benefit than free pages only. > > > >

On 26 October 2015 at 09:50, Andrey Smetanin <asmetanin at virtuozzo.com> wrote: > Signed-off-by: Andrey Smetanin <asmetanin at virtuozzo.com> > Reviewed-by: Roman Kagan <rkagan at virtuozzo.com> > Signed-off-by: Denis V. Lunev <den at openvz.org> > CC: Vitaly Kuznetsov <vkuznets at redhat.com> > CC: "K. Y. Srinivasan" <kys at

On Tue, Aug 11, 2015 at 08:00:21PM +0300, Roman Kagan wrote: > Opening the source VM and amending the properties in its internal > representation in accordance with command-line options fit nicely into > two isolated functions. Better to write this as: let rec main () = ... and open_source ... = ... and amend_source ... = ... and inspect_source ... = ... so

QEMU >= 2.10 started to do mandatory locking. This checks the QMP schema to see if we are using that version of qemu. (Note it is sometimes disabled in downstream builds, and it was also enabled in upstream prereleases with version 2.9.9x, so we cannot just check the version number). --- lib/guestfs-internal.h | 1 + lib/qemu.c | 60