March 2020 - Libguestfs - libguestfs List Archives

[PATCH v2 0/4] daemon: Translate device names if Linux device is unstable (RHBZ#1804207).
by Richard W.M. Jones 07 Mar '20

07 Mar '20

v1 was here: https://www.redhat.com/archives/libguestfs/2020-February/msg00220.html This patch series is a little bit better. It's still a bit of a hack. The _real_ fix for this is outlined in the TODO file (see patch 1) but that requires a lot more work than we could do before 1.42 is released, unless we delay 1.42 for a lot longer. I'm hoping with this to have something which works for 1.42, and then fix it properly in 1.43. Patch 2 is a debugging patch. It's separated out because we might consider reverting it in future once we are confident that the approach is working. Patch 3 is the second change necessary to how we launch the supermin appliance. This actually stands alone so could be reviewed separately. It requires a modest update to our baseline supermin version. Patch 4 should be ignored, it's just for my (additional) debugging. Rich.

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[PATCH nbdkit v2] New filter: limit: Limit number of clients that can connect.
by Richard W.M. Jones 07 Mar '20

07 Mar '20

This is a second version of the limit filter. v1 was posted here: https://www.redhat.com/archives/libguestfs/2020-March/msg00015.html I didn't bother to repost the other three patches because they are the same. The difference is this version of the filter takes security more seriously. It shouldn't be possible for malicious clients to connect more than limit=N times to the plugin now, which should be the main "threat" that this filter protects against. However malicious clients could still play tricks at the TCP level (eg. half-opened connections), connect as many times as they want to the server, and have as many NBD negotiations going on (albeit slowly). It would be possible to mitigate this further in the filter by counting "preconnected" clients separately, but the filter does not do this at present. Most likely if you were serious about this you'd want some other kind of protection outside the server. I'll note here that nbdkit has no time limit on NBD protocol negotiation. Possibly it should. $ nbdkit null $ telnet localhost 10809 Trying ::1... Connected to localhost. Escape character is '^]'. NBDMAGICIHAVEOPT <--- sits forever Rich.

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[PATCH nbdkit 0/4] server: Add nbdkit_shutdown() call and two new filters.
by Richard W.M. Jones 07 Mar '20

07 Mar '20

This adds a new nbdkit_shutdown() API whereby plugins and filters can request that the server shuts down (asynchronously) during the serving phase. Two new filters are added, one of which depends on this feature and the other not needing it but being somewhat related. Rich.

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Having integration tests "test the future" with QEMU
by Markus Armbruster 06 Mar '20

06 Mar '20

I understand libguestfs comes with integration tests. You might be interested in something I'm developing for QEMU 5.0 to permit "testing the future". I'd like to ensure it is actually useful before I continue. Let me know what you think. = Motivation = When layers above QEMU somehow miss feature deprecation, things continue to work until the deprecated interface goes away, at which point we have an entirely avoidable regression. We've been trying to get better at communicating feature deprecation to the layers above QEMU. An obvious first step was systematic documentation. However, documentation is all too easy to miss. Even if you don't miss it, you may need to continue using the deprecated feature with old versions of QEMU, and that logic needs to be tested. I'm working on a way to run QEMU with the deprecated features disabled. This permits "testing the future". >From my cover letter: This series extends QMP introspection to cover deprecation. Additionally, new option -compat lets you configure what to do when deprecated interfaces get used. This is intended for testing users of the management interfaces. It is experimental. -compat deprecated-input=<in-policy> configures what to do when deprecated input is received. Available policies: * accept: Accept deprecated commands and arguments (default) * reject: Reject them * crash: Crash -compat deprecated-output=<out-policy> configures what to do when deprecated output is sent. Available output policies: * accept: Emit deprecated command results and events (default) * hide: Suppress them For now, -compat covers only deprecated syntactic aspects of QMP. We may want to extend it to cover semantic aspects, CLI, and experimental features. If you want to learn more, check out the last three commit messages in the series. = Patches = [PATCH v2 00/30] Configurable policy for handling deprecated interfaces Message-Id: <20200303163505.32041-1-armbru(a)redhat.com> https://lists.nongnu.org/archive/html/qemu-devel/2020-03/msg00645.html = Git = Tag patchew/20200303163505.32041-1-armbru(a)redhat.com in repository https://github.com/patchew-project/qemu.git

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Bug: readdir() returning null on large number of files
by Sergey Ivanov 06 Mar '20

06 Mar '20

There's a bug (https://bugzilla.redhat.com/show_bug.cgi?id=1674392) and it's almost a year since it has been reported. Is there any plans/suggestions on its fixing? Didn't find any commits regarding this issue but maybe I'm just blind.

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[PATCH v3] windows: delay installation of qemu-ga MSI
by Tomáš Golembiovský 05 Mar '20

05 Mar '20

Instead of running firstboot script during early boot schedule a task delayed for 2 minutes. During the first boot, after virt-v2v conversion, Windows installs the drivers injected by virt-v2v. When this installation is finished Windows enforces some kind of internal reboot. This unfortunately terminates any running firstboot scripts thus killing the installation of qemu-ga MSI. This is just a best-effort mitigation. It can still happen (e.g. with slow disk drives) that the drivers are not yet installed when the delayed installation starts. On the other hand we cannot delay it too much otherwise we risk that the users logs in and will be doing some work when the MSI installation starts. After MSI installation finishes the VM needs to be rebooted which would be annoying if that would happen under users hands. Although this is not a best fix (that may come later as it is more complex, e.g. introducing waiting mechanism), the delay as it is defined works in most cases. And it dramaticaly improves the situations -- originaly I experienced more than 90% failure rate. Signed-off-by: Tomáš Golembiovský <tgolembi(a)redhat.com> --- common | 2 +- v2v/convert_windows.ml | 12 ++++-------- 2 files changed, 5 insertions(+), 9 deletions(-) diff --git a/common b/common index ea10827b..5371257c 160000 --- a/common +++ b/common @@ -1 +1 @@ -Subproject commit ea10827b4cfb3cfe5f782421c01d2902e5f73f90 +Subproject commit 5371257c3cf27fb09d5f2e31ba378b0e6ccf5df6 diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml index 0fda1d4e..bed5989a 100644 --- a/v2v/convert_windows.ml +++ b/v2v/convert_windows.ml @@ -429,14 +429,10 @@ popd List.iter ( fun msi_path -> let fb_script = "\ -echo Installing qemu-ga from " ^ msi_path ^ " -\"\\" ^ msi_path ^ "\" /norestart /qn /l+*vx \"%~dpn0.log\" -set elvl=!errorlevel! -echo Done installing qemu-ga error_level=!elvl! -if !elvl! == 0 ( - echo Restarting Windows... - shutdown /r /f /c \"rebooted by firstboot script\" -) +echo Removing any previously scheduled qemu-ga installation +schtasks.exe /Delete /TN Firstboot-qemu-ga /F +echo Scheduling delayed installation of qemu-ga from " ^ msi_path ^ " +powershell.exe -command \"$d = (get-date).AddSeconds(120); schtasks.exe /Create /SC ONCE /ST $d.ToString('HH:mm') /SD $d.ToString('MM/dd/yyyy') /RU SYSTEM /TN Firstboot-qemu-ga /TR \\\"C:\\" ^ msi_path ^ " /forcerestart /qn /l+*vx C:\\" ^ msi_path ^ ".log\\\"\" " in Firstboot.add_firstboot_script g inspect.i_root ("install " ^ msi_path) fb_script; -- 2.25.0

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[PATCH nbdkit] server: Only display "close: " debug message if callback is called.
by Richard W.M. Jones 04 Mar '20

04 Mar '20

For example if .preconnect fails, it printed the debug messages: debug: preconnect: ... debug: close: ... This confused me into thinking that the close callback was actually being called without a corresponding open. In fact it is not called in this case. Suppress the debug message unless the callback is actually being called. --- server/backend.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/server/backend.c b/server/backend.c index 51b56a48..108f4a25 100644 --- a/server/backend.c +++ b/server/backend.c @@ -241,10 +241,10 @@ backend_close (struct backend *b) struct handle *h = get_handle (conn, b->i); /* outer-to-inner order, opposite .open */ - controlpath_debug ("%s: close", b->name); if (h->handle) { assert (h->state & HANDLE_OPEN); + controlpath_debug ("%s: close", b->name); b->close (b, h->handle); } else -- 2.25.0

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[PATCH 0/1] Delay installation of QEMU-GA
by Tomáš Golembiovský 03 Mar '20

03 Mar '20

This is a replacement for previously posted patch "Delay firstboot scripts to some later time": https://www.redhat.com/archives/libguestfs/2019-November/msg00134.html Instead of delaying all the firstboot scripts we just delay the QEMU-GA installation that we know is problematic. I will possibly send a similar patch for RHEV-APT installation later. Tomáš Golembiovský (1): windows: delay installation of qemu-ga MSI v2v/convert_windows.ml | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) -- 2.25.0

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[PATCH v2] windows: delay installation of qemu-ga MSI
by Tomáš Golembiovský 03 Mar '20

03 Mar '20

Instead of running firstboot script during early boot schedule a task delayed for 2 minutes. During the first boot, after virt-v2v conversion, Windows installs the drivers injected by virt-v2v. When this installation is finished Windows enforces some kind of internal reboot. This unfortunately terminates any running firstboot scripts thus killing the installation of qemu-ga MSI. Signed-off-by: Tomáš Golembiovský <tgolembi(a)redhat.com> --- common | 2 +- v2v/convert_windows.ml | 12 ++++-------- 2 files changed, 5 insertions(+), 9 deletions(-) diff --git a/common b/common index ea10827b..5371257c 160000 --- a/common +++ b/common @@ -1 +1 @@ -Subproject commit ea10827b4cfb3cfe5f782421c01d2902e5f73f90 +Subproject commit 5371257c3cf27fb09d5f2e31ba378b0e6ccf5df6 diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml index 0fda1d4e..bed5989a 100644 --- a/v2v/convert_windows.ml +++ b/v2v/convert_windows.ml @@ -429,14 +429,10 @@ popd List.iter ( fun msi_path -> let fb_script = "\ -echo Installing qemu-ga from " ^ msi_path ^ " -\"\\" ^ msi_path ^ "\" /norestart /qn /l+*vx \"%~dpn0.log\" -set elvl=!errorlevel! -echo Done installing qemu-ga error_level=!elvl! -if !elvl! == 0 ( - echo Restarting Windows... - shutdown /r /f /c \"rebooted by firstboot script\" -) +echo Removing any previously scheduled qemu-ga installation +schtasks.exe /Delete /TN Firstboot-qemu-ga /F +echo Scheduling delayed installation of qemu-ga from " ^ msi_path ^ " +powershell.exe -command \"$d = (get-date).AddSeconds(120); schtasks.exe /Create /SC ONCE /ST $d.ToString('HH:mm') /SD $d.ToString('MM/dd/yyyy') /RU SYSTEM /TN Firstboot-qemu-ga /TR \\\"C:\\" ^ msi_path ^ " /forcerestart /qn /l+*vx C:\\" ^ msi_path ^ ".log\\\"\" " in Firstboot.add_firstboot_script g inspect.i_root ("install " ^ msi_path) fb_script; -- 2.25.0

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