June 2022 - Devel - libvirt List Archives

Summary on new backup interfaces in QEMU
by Vladimir Sementsov-Ogievskiy 21 Feb '23

21 Feb '23

Hi all! Here I want to summarize new interfaces and use cases for backup in QEMU. TODO for me: convert this into good rst documentation in docs/. OK, let's begin. First, note that drive-backup qmp command is deprecated. Next, some terminology: push backup: the whole process is inside QEMU process, also may be called "internal backup" pull backup: QEMU only exports a kind of snapshot (for example by NBD), and third party software reads this export and stores it somehow, also called "external backup" copy-before-write operations: We usually do backup of active disk, guest is running and may write to the disk during the process of backup. When guest wants to rewrite data region which is not backed up yet, we must stop this guest write, and copy original data to somewhere before continuing guest write. That's a copy-before-write operation. image-fleecing: the technique that allows to export a "snapshotted" state of the active disk with help of copy-before-write operations. We create a temporary image - target for copy-before-write operations, and provide an interface to the user to read the "snapshotted" state. And for read, we do read from temporary image the data which is already changed in original active disk, and we read unchanged data directly from active disk. The temporary image itself is also called "reverse delta" or "reversed delta". == Simple push backup == Just use blockdev-backup, nothing new here. I just note some technical details, that are relatively new: 1. First, backup job inserts copy-before-write filter above source disk, to do copy-before-write operation. 2. Created copy-before-write filter shares internal block-copy state with backup job, so they work in collaboration, to not copy same things twice. == Full pull backup == Assume, we are going to do incremental backup in future, so we also need to create a dirty bitmap, to track dirtiness of active disk since full backup. 1. Create empty temporary image for fleecing. It must be of the same size as active disk. It's not necessary to be qcow2, and if it's a qcow2, you shouldn't make the original active disk a backing file for the new temporary qcow2 image (it was necessary in old fleecing scheme). Example: qemu-img create -f qcow2 temp.qcow2 64G 2. Initialize fleecing scheme and create dirty bitmap for future incremental backup. Assume, disk0 is an active disk, attached to qdev-id sda, to be backed up. qmp: transaction [ block-dirty-bitmap-add {node: disk0, name: bitmap0, persistent: true} blockdev-add* {node-name: tmp-protocol, driver: file, filename: temp.qcow2} blockdev-add {node-name: tmp, driver: qcow2, file: tmp-protocol} blockdev-add {node-name: cbw, driver: copy-before-write, file: disk0, target: tmp} blockdev-replace** {parent-type: qdev, qdev-id: sda, new-child: cbw} blockdev-add {node-name: acc, driver: snapshot-access, file: cbw} ] qmp: nbd-server-start {...} qmp: nbd-server-add {device: acc, ...} This way we create the following block-graph: [guest] [NBD export] | | | root | root v file v [copy-before-write]<------[snapshot-access] | | | file | target v v [active-disk] [temp.qcow2] * "[PATCH 0/2] blockdev-add transaction" series needed for this ** "[PATCH v3 00/11] blockdev-replace" series needed for this Note additional useful options for copy-before-write filter: "[PATCH 0/3] block: copy-before-write: on-cbw-error behavior" provides possibility of option on-cbw-error=break-snapshot, which means that on failure of CBW operation we will not break guest write, but instead all further reads by NBD client will fail, which formally means: break the backup process, not guest write. "[PATCH 0/4] block: copy-before-write: cbw-timeout" provides an option cbw-timeout, to set a timeout for CBW operations. That's very useful to avoid guest stuck. 3. Now third party backup tool can read data from NBD export NBD_CMD_TRIM (discard) operation is supported on the export, it has the following effects: 1. discard this data from temp image, if it is stored here 2. avoid further copy-before-write operation (guest is free to rewrite corresponding data with no extra latency) 3. all further read requests from discarded areas by NBD client will fail So, NBD client may discard regions that are already backed up to avoid extra latency for guest writes and to free disk space on the host. Possible TODO here is to implement NBD protocol extension, that allows to READ & DISCARD in command. In this case we avoid extra command in the wire, but lose possibility of retrying the READ operation if it failed. 4. After backup is complete, we should destroy the fleecing scheme: qmp: nbd-server-stop qmp: blockdev-del {node-name: acc} qmp: blockdev-replace {parent-type: qdev, qdev-id: sda, new-child: disk0} qmp: blockdev-del {node-name: cbw} qmp: blockdev-del {node-name: tmp} qmp: blockdev-del {node-name: tmp-protocol} 5. If backup failed, we should remove created dirty bitmap: qmp: block-dirty-bitmap-remove {node: disk0, name: bitmap0} == Incremental pull backup == OK, now we have a bitmap called bitmap0, and want to do incremental backup, accordingly to that bitmap. In short, we want: - create a new bitmap to continue dirty tracking for next incremental backup - export "snapshotted" state of disk0 through NBD - export "frozen" bitmap, so that external tool know what to copy Mostly, all points remains the same, let's go through: 1. Create empty temporary image for fleecing -- same as for full backup, no difference 2. Initialize fleecing scheme and create dirty bitmap for future incremental backup. qmp: transaction [ block-dirty-bitmap-add {node: disk0, name: bitmap1, persistent: true} block-dirty-bitmap-disable {node: disk0, name: bitmap0} blockdev-add {node-name: tmp-protocol, driver: file, filename: temp.qcow2} blockdev-add {node-name: tmp, driver: qcow2, file: tmp-protocol} blockdev-add {node-name: cbw, driver: copy-before-write, file: disk0, target: tmp, bitmap: {node: disk0, name: bitmap0}} blockdev-replace {parent-type: qdev, qdev-id: sda, new-child: cbw} blockdev-add {node-name: acc, driver: snapshot-access, file: cbw} ] qmp: nbd-server-start {...} qmp: block-export-add {type: nbd, node-name: acc, bitmaps: [{node: disk0, name: bitmap0}]} 3. Now third party backup tool can read data from NBD export - Client may negotiate meta contexts, to query exported dirty bitmap by NBD_BLOCK_STATUS commend - If client reads "not-dirty" (by bitmap0) areas, it gets an error. - NBD_CMD_TRIM (discard) works as for full backup, no difference 4. After backup is complete, we should destroy the fleecing scheme: - Same as for full backup 5. Next, we should handle dirty bitmaps: 5.1 Failure path Merge-back bitmap1 to bitmap0 and continue tracking in bitmap0: qmp: transaction [ block-dirty-bitmap-enable {node: disk0, name: bitmap0} block-dirty-bitmap-merge {node: disk0, target: bitmap0, bitmaps: ['bitmap1']} block-dirty-bitmap-remove {node: disk0, name: bitmap1} ] 5.2 Success path We have two possible user scenarios on success: 5.2.1 Continue tracking for next incremental backup in bitmap1 In this case, just remove bitmap0: qmp: block-dirty-bitmap-remove {node: disk0, name: bitmap0} Or you may not delete bitmap0 and keep it disabled, to be reused in future for differential backup (see below). 5.2.2 Continue tracking for next incremental backup in bitmap0 (assume, we always work with one bitmap and don't want any kind of differential backups, and don't associate bitmap name with stored backups) In this case, enable and clear bitmap0, merge bitmap1 to bitmap0 and remove bitmap1: qmp: transaction [ block-dirty-bitmap-enable {node: disk0, name: bitmap0} block-dirty-bitmap-clear {node: disk0, name: bitmap0} block-dirty-bitmap-merge {node: disk0, target: bitmap0, bitmaps: ['bitmap1']} block-dirty-bitmap-remove {node: disk0, name: bitmap1} ] == Push backup with fleecing full/incremental == Reasoning: the main problem of simple push backup is that guest writes may be seriously affected by copy-on-write operations, when backup target is slow. To solve this problem, we'll use the scheme like for pull backup: we create local temporary image, which is a target for copy-before-write operations, and instead of exporting the "snapshot-access" node we start internal backup from it to the target. So, the scheme and commands looks exactly the same as for full and incremental pull backup. The only difference is that we don't need to start nbd export, but instead we should add target node to qemu and start internal backup. And good thing is that it may be done in same transaction with initializing fleecing scheme: qmp: transaction [ ... initialize fleecing scheme for full or incremental backup ... # Add target node. Here is qcow2 added, but it may be nbd node or something else blockdev-add {node-name: target-protocol, driver: file, filename: target.qcow2} blockdev-add {node-name: target, driver: qcow2, file: target-protocol} # Start backup blockdev-backup {device: acc, target: target, ...} ] If it is an incremental backup, pass also bitmap parameter: blockdev-backup {..., bitmap: bitmap0, sync: incremental, bitmap-mode: never} Note bitmap-mode=never: this means that backup will do nothing with bitmap0, so we have same scheme like for pull backups (handle bitmaps by hand after backup). Still, push-backup scheme may be adopted to use other bitmap modes. What we lack here is discarding in 'acc' node after successful copying of the block to the target, to safe disk space and avoid extra copy-before-write operations. It's a TODO, should be implemented like discard-source parameter for blockdev-backup. == Differential backups == I'm not fan of this idea, but I think it should be described. Assume we have already a chain of incremental backups (represented as qcow2 chain on backup storage server, for example). They corresponds to some points in time: T0, T1, T2, T3. Assume T3 is the last backup. If we want to create usual incremental backup, it would be diff between T3 and current time (which becomes T4). Differential backup say: I want to make backup starting from T1 to current time. What's for? Maybe T2 and T3 was removed or somehow damaged.. How to do that in Qemu: on each incremental backup you start a new bitmap, and _keep_ old one as disabled. This way we have bitmap0 (which presents diff between T0 and T1), bitmap1 (diff T1 T2), bitmap2 (diff T2 T3), and bitmap3 which shows diff from T3 up to current time. bitmap3 is the only enabled bitmap and others are disabled. So, to make differential backup, use block-dirty-bitmap-merge command, to merge all bitmaps you need into one, and than use it in any backup scheme. The drawback is that all these disabled bitmaps eat RAM. Possible solution is to not keep them in RAM, it's OK to keep them in qcow2, and load only on demand. That's not realized now and that's a TODO for thous who want differential backups. -- Best regards, Vladimir

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Test failures on macOS 12
by Andrea Bolognani 10 Aug '22

10 Aug '22

I'm trying to enable CI coverage for macOS 12, but I'm running into a couple of issues that I'm not sure how to handle. Note that the test suite currently passes on macOS 11[1], so these failures have to be a consequence to changes made to macOS that we haven't yet learned how to cope with. The first one is in vircryptotest: Encrypt aes265cbc ... Expected ciphertext doesn't match I've added some debug statements and it looks like the generated data is different every time, which seems like a pretty good indication that virrandommock is not being picked up correctly. This is not the only test program that uses that specific mock though, so I'm not sure what makes it fail when all the others are succeeding. The other issue is in qemuxml2argvtest: error : virCommandWait:2752 : internal error: Child process (/usr/libexec/qemu/vhost-user/test-vhost-user-gpu --print-capabilities) unexpected fatal signal 6: dyld[8896]: symbol not found in flat namespace '_virQEMUCapsGet' error : qemuVhostUserFillDomainGPU:394 : operation failed: Unable to find a satisfying vhost-user-gpu So the various virFileWrapperAddPrefix() calls that cause the contents of tests/qemuvhostuserdata/ to override the host's own vhostuser configuration are still effective, but for some reason the trivial test-vhost-user-gpu shell script can't be run successfully because an internal libvirt symbol can't be found somehow? Confusing. Roman, does any of this ring a bell? Any chance you could investigate? macOS 12 has been out for a while now so I'd be very keen to have it added to CI. Thanks in advance! [1] https://gitlab.com/libvirt/libvirt/-/jobs/2421455154 -- Andrea Bolognani / Red Hat / Virtualization

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[PATCH v2 0/9] qemu: Enable SCHED_CORE for domains and helper processes
by Michal Privoznik 10 Aug '22

10 Aug '22

v2 of: https://listman.redhat.com/archives/libvir-list/2022-May/230902.html While technically, the original series was "just" and RFC, it got proper review and thus I'm marking this as v2. What's still missing? ===================== * Per Dario's suggestion, we should take vcpu pinning (and possibly emulator pinning as well) into account, so that the guest doesn't have to do SCHED_CORE inside it. * per-VM knob to enable/disable SCHED_CORE. But as discussed under my RFC patches, it's probably not needed, at least for now. It can always be added later, should somebody need it. Diff to v1: =========== * Turned qemu.conf knob into an enum rather than boolean, so that users can chose whether helper processes are placed into the emulator group too * Cleaned up virCommand* code; per Dan's suggestion use one variable to differentiate runAlone/runAmong states, instead of two. Michal Prívozník (9): qemu_dbus: Separate PID read code into qemuDBusGetPID qemu_vhost_user_gpu: Export qemuVhostUserGPUGetPid() qemu_tpm: Expose qemuTPMEmulatorGetPid() qemu_virtiofs: Separate PID read code into qemuVirtioFSGetPid virprocess: Core Scheduling support virCommand: Introduce APIs for core scheduling qemu_conf: Introduce a knob to set SCHED_CORE qemu: Enable SCHED_CORE for domains and helper processes qemu: Place helper processes into the same trusted group src/libvirt_private.syms | 6 ++ src/qemu/libvirtd_qemu.aug | 1 + src/qemu/qemu.conf.in | 14 ++++ src/qemu/qemu_conf.c | 42 ++++++++++ src/qemu/qemu_conf.h | 11 +++ src/qemu/qemu_dbus.c | 42 +++++++--- src/qemu/qemu_dbus.h | 4 + src/qemu/qemu_extdevice.c | 120 ++++++++++++++++++++++++++++ src/qemu/qemu_extdevice.h | 3 + src/qemu/qemu_process.c | 9 +++ src/qemu/qemu_security.c | 4 + src/qemu/qemu_tpm.c | 2 +- src/qemu/qemu_tpm.h | 7 ++ src/qemu/qemu_vhost_user_gpu.c | 2 +- src/qemu/qemu_vhost_user_gpu.h | 8 ++ src/qemu/qemu_virtiofs.c | 41 +++++++--- src/qemu/qemu_virtiofs.h | 5 ++ src/qemu/test_libvirtd_qemu.aug.in | 1 + src/util/vircommand.c | 63 +++++++++++++++ src/util/vircommand.h | 5 ++ src/util/virprocess.c | 124 +++++++++++++++++++++++++++++ src/util/virprocess.h | 8 ++ 22 files changed, 494 insertions(+), 28 deletions(-) -- 2.35.1

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[libvirt] Semantic change in v4.3 slows down image creation and snapshots (on ZFS)
by Christian Ehrhardt 31 Jul '22

31 Jul '22

Hi, when discussing bug [1] triggered by [2] Daniel and I have found that the change [3] which is in since v4.3 was a semantic change to the behavior of libvirt. virt-manager used and still does issue a volume XML like: <volume> <name>disk.qcow2</name> <capacity>16106127360</capacity> <allocation>16106127360</allocation> <target> <format type="qcow2"/> <features> <lazy_refcounts/> </features> </target> </volume> Up until the commit above that was using preallocation=metadata, but now uses preallocation=falloc. In many cases (read: Fileystems) that won't be very user-visible, but if you are running on ZFS (or anything else that can't fallocate well) this is made worse by [4] slowing down these operations a lot. After the POV for virt-manager seems to have settled on the bug [1] referenced the remaining question is if libvirt should revert/modify the change [3] - and that we agreed required a wider discussion to be had here, hence this mail. [1]: https://bugzilla.redhat.com/show_bug.cgi?id=1759454 [2]: https://bugs.launchpad.net/virt-manager/+bug/1847105 [3]: https://libvirt.org/git/?p=libvirt.git;a=commit;h=c9ec7088c7a3f4cd26bb471f1… [4]: https://github.com/zfsonlinux/zfs/issues/326 -- Christian Ehrhardt Software Engineer, Ubuntu Server Canonical Ltd

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[libvirt][PATCH v11 0/4] Support query and use SGX
by Lin Yang 25 Jul '22

25 Jul '22

This patch series provides support for enabling Intel's Software Guard Extensions (SGX) feature in guest VM. Giving the SGX support in QEMU had been merged. Intel SGX is a set of instructions that increases the security of application code and data, giving them more protection from disclosure or modification. Developers can partition sensitive information into enclaves, which are areas of execution in memory with more security protection. It depends on QEMU fixing[1], which will move cpu QOM object from /machine/unattached/device[nn] to /machine/cpu[nn]. It requires libvirt to change the default cpu QOM object location once QEMU patch gets accepted, but it is out of this SGX patch scope. The typical flow looks below at very high level: 1. Calls virConnectGetDomainCapabilities API to domain capabilities that includes the following SGX information. <feature> ... <sgx supported='yes'> <epc_size unit='KiB'>N</epc_size> </sgx> ... </feature> 2. User requests to start a guest calling virCreateXML() with SGX requirement. It does not support NUMA yet, since latest QEMU 6.2 release does not support NUMA. It should contain <devices> ... <memory model='sgx-epc'> <target> <size unit='KiB'>N</size> </target> </memory> ... </devices> Please note that SGX NUMA support will be implemented in future patches. [1] https://lists.nongnu.org/archive/html/qemu-devel/2022-01/msg03534.html Haibin Huang (2): qemu: provide support to query the SGX capability conf: expose SGX feature in domain capabilities Lin Yang (2): conf: Introduce SGX EPC element into device memory xml qemu: Add command-line to generate SGX EPC memory backend docs/formatdomain.rst | 9 +- docs/formatdomaincaps.rst | 26 ++++ src/conf/domain_capabilities.c | 29 ++++ src/conf/domain_capabilities.h | 13 ++ src/conf/domain_conf.c | 6 + src/conf/domain_conf.h | 1 + src/conf/domain_validate.c | 16 ++ src/conf/schemas/domaincaps.rng | 22 ++- src/conf/schemas/domaincommon.rng | 1 + src/libvirt_private.syms | 1 + src/qemu/qemu_alias.c | 6 +- src/qemu/qemu_capabilities.c | 143 ++++++++++++++++++ src/qemu/qemu_capabilities.h | 6 + src/qemu/qemu_capspriv.h | 4 + src/qemu/qemu_command.c | 54 ++++++- src/qemu/qemu_domain.c | 38 +++-- src/qemu/qemu_domain_address.c | 6 + src/qemu/qemu_driver.c | 1 + src/qemu/qemu_monitor.c | 10 ++ src/qemu/qemu_monitor.h | 3 + src/qemu/qemu_monitor_json.c | 104 ++++++++++++- src/qemu/qemu_monitor_json.h | 9 ++ src/qemu/qemu_process.c | 2 + src/qemu/qemu_validate.c | 8 + src/security/security_apparmor.c | 1 + src/security/security_dac.c | 2 + src/security/security_selinux.c | 2 + tests/domaincapsdata/bhyve_basic.x86_64.xml | 1 + tests/domaincapsdata/bhyve_fbuf.x86_64.xml | 1 + tests/domaincapsdata/bhyve_uefi.x86_64.xml | 1 + tests/domaincapsdata/empty.xml | 1 + tests/domaincapsdata/libxl-xenfv.xml | 1 + tests/domaincapsdata/libxl-xenpv.xml | 1 + .../domaincapsdata/qemu_2.11.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_2.11.0-tcg.x86_64.xml | 1 + tests/domaincapsdata/qemu_2.11.0.s390x.xml | 1 + tests/domaincapsdata/qemu_2.11.0.x86_64.xml | 1 + .../domaincapsdata/qemu_2.12.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_2.12.0-tcg.x86_64.xml | 1 + .../qemu_2.12.0-virt.aarch64.xml | 1 + tests/domaincapsdata/qemu_2.12.0.aarch64.xml | 1 + tests/domaincapsdata/qemu_2.12.0.ppc64.xml | 1 + tests/domaincapsdata/qemu_2.12.0.s390x.xml | 1 + tests/domaincapsdata/qemu_2.12.0.x86_64.xml | 1 + .../domaincapsdata/qemu_3.0.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_3.0.0-tcg.x86_64.xml | 1 + tests/domaincapsdata/qemu_3.0.0.ppc64.xml | 1 + tests/domaincapsdata/qemu_3.0.0.s390x.xml | 1 + tests/domaincapsdata/qemu_3.0.0.x86_64.xml | 1 + .../domaincapsdata/qemu_3.1.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_3.1.0-tcg.x86_64.xml | 1 + tests/domaincapsdata/qemu_3.1.0.ppc64.xml | 1 + tests/domaincapsdata/qemu_3.1.0.x86_64.xml | 1 + .../domaincapsdata/qemu_4.0.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_4.0.0-tcg.x86_64.xml | 1 + .../qemu_4.0.0-virt.aarch64.xml | 1 + tests/domaincapsdata/qemu_4.0.0.aarch64.xml | 1 + tests/domaincapsdata/qemu_4.0.0.ppc64.xml | 1 + tests/domaincapsdata/qemu_4.0.0.s390x.xml | 1 + tests/domaincapsdata/qemu_4.0.0.x86_64.xml | 1 + .../domaincapsdata/qemu_4.1.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_4.1.0-tcg.x86_64.xml | 1 + tests/domaincapsdata/qemu_4.1.0.x86_64.xml | 1 + .../domaincapsdata/qemu_4.2.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_4.2.0-tcg.x86_64.xml | 1 + .../qemu_4.2.0-virt.aarch64.xml | 1 + tests/domaincapsdata/qemu_4.2.0.aarch64.xml | 1 + tests/domaincapsdata/qemu_4.2.0.ppc64.xml | 1 + tests/domaincapsdata/qemu_4.2.0.s390x.xml | 1 + tests/domaincapsdata/qemu_4.2.0.x86_64.xml | 1 + .../domaincapsdata/qemu_5.0.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_5.0.0-tcg.x86_64.xml | 1 + .../qemu_5.0.0-virt.aarch64.xml | 1 + tests/domaincapsdata/qemu_5.0.0.aarch64.xml | 1 + tests/domaincapsdata/qemu_5.0.0.ppc64.xml | 1 + tests/domaincapsdata/qemu_5.0.0.x86_64.xml | 1 + .../domaincapsdata/qemu_5.1.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_5.1.0-tcg.x86_64.xml | 1 + tests/domaincapsdata/qemu_5.1.0.sparc.xml | 1 + tests/domaincapsdata/qemu_5.1.0.x86_64.xml | 1 + .../domaincapsdata/qemu_5.2.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_5.2.0-tcg.x86_64.xml | 1 + .../qemu_5.2.0-virt.aarch64.xml | 1 + tests/domaincapsdata/qemu_5.2.0.aarch64.xml | 1 + tests/domaincapsdata/qemu_5.2.0.ppc64.xml | 1 + tests/domaincapsdata/qemu_5.2.0.s390x.xml | 1 + tests/domaincapsdata/qemu_5.2.0.x86_64.xml | 1 + .../domaincapsdata/qemu_6.0.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_6.0.0-tcg.x86_64.xml | 1 + .../qemu_6.0.0-virt.aarch64.xml | 1 + tests/domaincapsdata/qemu_6.0.0.aarch64.xml | 1 + tests/domaincapsdata/qemu_6.0.0.s390x.xml | 1 + tests/domaincapsdata/qemu_6.0.0.x86_64.xml | 1 + .../domaincapsdata/qemu_6.1.0-q35.x86_64.xml | 1 + .../domaincapsdata/qemu_6.1.0-tcg.x86_64.xml | 1 + tests/domaincapsdata/qemu_6.1.0.x86_64.xml | 1 + .../domaincapsdata/qemu_6.2.0-q35.x86_64.xml | 4 + .../domaincapsdata/qemu_6.2.0-tcg.x86_64.xml | 4 + .../qemu_6.2.0-virt.aarch64.xml | 1 + tests/domaincapsdata/qemu_6.2.0.aarch64.xml | 1 + tests/domaincapsdata/qemu_6.2.0.ppc64.xml | 1 + tests/domaincapsdata/qemu_6.2.0.x86_64.xml | 4 + .../domaincapsdata/qemu_7.0.0-q35.x86_64.xml | 4 + .../domaincapsdata/qemu_7.0.0-tcg.x86_64.xml | 4 + .../qemu_7.0.0-virt.aarch64.xml | 1 + tests/domaincapsdata/qemu_7.0.0.aarch64.xml | 1 + tests/domaincapsdata/qemu_7.0.0.ppc64.xml | 1 + tests/domaincapsdata/qemu_7.0.0.x86_64.xml | 4 + .../caps_6.2.0.x86_64.replies | 22 ++- .../caps_6.2.0.x86_64.xml | 5 + .../caps_7.0.0.x86_64.replies | 22 ++- .../caps_7.0.0.x86_64.xml | 5 + .../sgx-epc.x86_64-6.2.0.args | 37 +++++ tests/qemuxml2argvdata/sgx-epc.xml | 36 +++++ tests/qemuxml2argvtest.c | 2 + .../sgx-epc.x86_64-latest.xml | 52 +++++++ tests/qemuxml2xmltest.c | 2 + 117 files changed, 769 insertions(+), 36 deletions(-) create mode 100644 tests/qemuxml2argvdata/sgx-epc.x86_64-6.2.0.args create mode 100644 tests/qemuxml2argvdata/sgx-epc.xml create mode 100644 tests/qemuxml2xmloutdata/sgx-epc.x86_64-latest.xml -- 2.25.1

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[PATCH] cmdQemuMonitorCommandQMPWrap: Reset ignored errors from JSON parsing
by Peter Krempa 25 Jul '22

25 Jul '22

'cmdQemuMonitorCommandQMPWrap' is checking whether the user provided string is not valid JSON to avoid wrapping it. In cases where it's not JSON we ignore the error and add the wrapper. If the caller then reports a different non-libvirt error the error from the JSON parsing would be printed as well. Reset errors we ignore: # virsh qemu-monitor-command cd --pass-fds a asdf error: Unable to parse FD number 'a' error: internal error: cannot parse json asdf: lexical error: invalid char in json text. asdf (right here) ------^ In the above case 'asdf' is not valid JSON, but the code did wrap it into '{"execute":"asdf"}', the only problem is the argument for --pass-fds. Signed-off-by: Peter Krempa <pkrempa(a)redhat.com> --- tools/virsh-domain.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index 9b1b14cdc2..743660e794 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -9769,6 +9769,8 @@ cmdQemuMonitorCommandQMPWrap(vshControl *ctl, if (virJSONValueIsObject(fullcmdjson)) return g_steal_pointer(&fullcmd); + vshResetLibvirtError(); + /* we try to wrap the command and possible arguments into a JSON object, if * we as fall back we pass through what we've got from the user */ @@ -9787,6 +9789,8 @@ cmdQemuMonitorCommandQMPWrap(vshControl *ctl, * JSON object wrapper and try using that */ g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER; + vshResetLibvirtError(); + virBufferAddLit(&buf, "{"); /* opt points to the _ARGV option bit containing the command so we'll * iterate through the arguments now */ -- 2.35.1

2 2

[libvirt PATCH 0/9] [RFC] Dynamic CPU models
by Tim Wiederhake 18 Jul '22

18 Jul '22

libvirt and qemu cpu models are out of sync. libvirt cpu models are considered static and never changing, whereas qemu cpu models have changed over time. This leads to problems and confusion for users, as the cpu models they specify may have different features than what they expect. This series introduces two new APIs to enumerate and retrieve cpu models dynamically from the hypervisor at runtime, allowing the user to make use of cpu models from newer hypervisor versions even if libvirt is not aware of them. These two new functions are intended as building blocks onto which higher-level functionality can be build, e.g. the ability to specify a hypervisor cpu model directly in a domain xml. With these two functions alone this has to be done manually for now, i.e. enumerate the available cpu models, retrieve the cpu description and manually insert it into the domain xml accordingly: $ virsh hypervisor-cpu-models --arch x86_64 Name Alias ---------------------------------------------------- max host base qemu64-v1 qemu64 qemu64-v1 qemu32-v1 qemu32 qemu32-v1 phenom-v1 phenom phenom-v1 (...) $ virsh hypervisor-cpu-definition --machine pc --arch x86_64 qemu64 <cpu> <model>qemu64</model> <feature name='cmov'/> <feature name='mmx'/> <feature name='xd'/> <feature name='x-intel-pt-auto-level'/> <feature name='kvm_asyncpf'/> <feature name='kvm-asyncpf'/> <feature name='legacy-cache'/> <feature name='vmware-cpuid-freq'/> <feature name='mce'/> <feature name='mca'/> <feature name='msr'/> <feature name='fxsr'/> <feature name='cpuid-0xb'/> <feature name='kvm_pv_eoi'/> <feature name='pni'/> <feature name='x2apic'/> <feature name='i64'/> <feature name='pae'/> <feature name='pat'/> <feature name='sse'/> <feature name='kvm_nopiodelay'/> <feature name='kvm-nopiodelay'/> <feature name='kvmclock-stable-bit'/> <feature name='hypervisor'/> <feature name='syscall'/> <feature name='x-migrate-smi-count'/> <feature name='full-cpuid-auto-level'/> <feature name='sse3'/> <feature name='sse2'/> <feature name='kvm-pv-eoi'/> <feature name='cx8'/> <feature name='pge'/> <feature name='fill-mtrr-mask'/> <feature name='cx16'/> <feature name='de'/> <feature name='clflush'/> <feature name='tsc'/> <feature name='fpu'/> <feature name='check'/> <feature name='apic'/> <feature name='kvm-steal-time'/> <feature name='kvm_steal_time'/> <feature name='kvmclock'/> <feature name='l3-cache'/> <feature name='nx'/> <feature name='tcg-cpuid'/> <feature name='lm'/> <feature name='pse'/> <feature name='sep'/> <feature name='kvm'/> <feature name='lahf-lm'/> <feature name='lahf_lm'/> <feature name='mtrr'/> <feature name='pse36'/> </cpu> The returned cpu description is currently completely unfiltered, as can be seen by the duplicate entries differing only in "-" vs. "_" usage, inclusion of experimental feature flags and generally, flags that are not recognized by libvirt. One possibility to adress this would be to extend virQEMUCapsCPUFeatureTranslate. Before I continue with this, I would love to hear other people's thoughts, comments and potential use cases. Cheers, Tim Tim Wiederhake (9): qemuMonitorCPUDefInfo: Add alias libvirt: introduce virConnectGetHypervisorCPUModelNames public API remote: Add RPC support for the virConnectGetHypervisorCPUModelNames API qemu: implement virConnectGetHypervisorCPUModelNames API tools: Report hypervisor cpu model names libvirt: introduce virConnectGetHypervisorCPUModelDefinition public API remote: Add support for the virConnectGetHypervisorCPUModelDefinition API qemu: Implement virConnectGetHypervisorCPUModelDefinition API tools: Report hypervisor cpu model definitions docs/manpages/virsh.rst | 27 ++++++ include/libvirt/libvirt-host.h | 13 +++ src/driver-hypervisor.h | 17 ++++ src/libvirt-host.c | 109 +++++++++++++++++++++++ src/libvirt_public.syms | 2 + src/qemu/qemu_driver.c | 105 ++++++++++++++++++++++ src/qemu/qemu_monitor.c | 2 + src/qemu/qemu_monitor.h | 1 + src/qemu/qemu_monitor_json.c | 3 + src/remote/remote_daemon_dispatch.c | 76 ++++++++++++++++ src/remote/remote_driver.c | 100 +++++++++++++++++++++ src/remote/remote_protocol.x | 37 +++++++- src/remote_protocol-structs | 27 ++++++ tools/virsh-host.c | 132 ++++++++++++++++++++++++++++ 14 files changed, 650 insertions(+), 1 deletion(-) -- 2.31.1

2 22

[PATCH] qemu_monitor_json: Implement logic for setting iothread.thread-pool-{min, max}
by Michal Privoznik 07 Jul '22

07 Jul '22

When virDomainSetIOThreadParams() API is called, well its QEMU impl: qemuDomainSetIOThreadParams() then typed params are parsed by qemuDomainIOThreadParseParams() into this qemuMonitorIOThreadInfo struct. In the struct we have a <int, bool> pair for every IOThread attribute we can tune through monitor. The struct is then passed to qemuMonitorJSONSetIOThread() which looks at the bool and if set then the corresponding attribute is set to given value. Each attribute is thus changed in a separate call. While this works for attributes independent of each other ("poll-max-ns", "poll-grow", "poll-shrink"), it does not always work for the other attributes ("thread-pool-min" and "thread-pool-max"). The limitation here is that the lower boundary (minimum) has to be lower (or equal to) the upper boundary (maximum) at all times. This means, that in some cases we might need to set attributes in reversed order to meet the constraint. Resolves: https://gitlab.com/libvirt/libvirt/-/issues/339 Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com> --- src/qemu/qemu_monitor_json.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 3aad2ab212..80696de731 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -7428,6 +7428,7 @@ qemuMonitorJSONSetIOThread(qemuMonitor *mon, { g_autofree char *path = NULL; qemuMonitorJSONObjectProperty prop; + bool setMaxFirst = false; path = g_strdup_printf("/objects/iothread%u", iothreadInfo->iothread_id); @@ -7443,8 +7444,32 @@ qemuMonitorJSONSetIOThread(qemuMonitor *mon, VIR_IOTHREAD_SET_PROP("poll-max-ns", poll_max_ns); VIR_IOTHREAD_SET_PROP("poll-grow", poll_grow); VIR_IOTHREAD_SET_PROP("poll-shrink", poll_shrink); - VIR_IOTHREAD_SET_PROP("thread-pool-min", thread_pool_min); - VIR_IOTHREAD_SET_PROP("thread-pool-max", thread_pool_max); + + if (iothreadInfo->set_thread_pool_min && + iothreadInfo->set_thread_pool_max) { + int curr_max = -1; + + /* By default, the minimum is set first, followed by the maximum. But + * if the current maximum is below the minimum we want to set we need + * to set the maximum first. Otherwise would get an error because we + * would be attempting to shift minimum above maximum. */ + prop.type = QEMU_MONITOR_OBJECT_PROPERTY_INT; + if (qemuMonitorJSONGetObjectProperty(mon, path, + "thread-pool-max", &prop) < 0) + return -1; + curr_max = prop.val.iv; + + if (curr_max < iothreadInfo->thread_pool_min) + setMaxFirst = true; + } + + if (setMaxFirst) { + VIR_IOTHREAD_SET_PROP("thread-pool-max", thread_pool_max); + VIR_IOTHREAD_SET_PROP("thread-pool-min", thread_pool_min); + } else { + VIR_IOTHREAD_SET_PROP("thread-pool-min", thread_pool_min); + VIR_IOTHREAD_SET_PROP("thread-pool-max", thread_pool_max); + } #undef VIR_IOTHREAD_SET_PROP -- 2.35.1

2 1

[libvirt PATCH v2] tools: add virt-qmp-proxy for proxying QMP clients to libvirt QEMU guests
by Daniel P. Berrangé 01 Jul '22

01 Jul '22

Libvirt provides QMP passthrough APIs for the QEMU driver and these are exposed in virsh. It is not especially pleasant, however, using the raw QMP JSON syntax. QEMU has a tool 'qmp-shell' which can speak QMP and exposes a human friendly interactive shell. It is not possible to use this with libvirt managed guest, however, since only one client can attach to he QMP socket at any point in time. The virt-qmp-proxy tool aims to solve this problem. It opens a UNIX socket and listens for incoming client connections, speaking QMP on the connected socket. It will forward any QMP commands received onto the running libvirt QEMU guest, and forward any replies back to the QMP client. $ virsh start demo $ virt-qmp-proxy demo demo.qmp & $ qmp-shell demo.qmp Welcome to the QMP low-level shell! Connected to QEMU 6.2.0 (QEMU) query-kvm { "return": { "enabled": true, "present": true } } Note this tool of course has the same risks as the raw libvirt QMP passthrough. It is safe to run query commands to fetch information but commands which change the QEMU state risk disrupting libvirt's management of QEMU, potentially resulting in data loss/corruption in the worst case. Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com> --- Changed in v2: - Rewrote to not be such a gross hack, specifically - Wired up usage of libvirt event loop for sock I/O - Register with libvirt for QMP events - Incrementally read from socket & try json parsing until we get a full command, instead of assuming a full command in one read - Forwarding of passed FDs in both directions (libvirt -> client untested, since AFAIK, no QMP cmd returns FDs currently) Other thought.... This patch is against libvirt.git but has a dependancy on the libvirt-python.git APIs. If we put this in libvirt-client RPM then we get a new dep on python. Perhaps better to have this live in libvirt-python.git/examples, though I would like it present as a standard tool ? Another option is to bundle with virt-install which is a python app commonly present on virt hosts ? docs/manpages/meson.build | 1 + docs/manpages/virt-qmp-proxy.rst | 120 +++++++++++ tools/meson.build | 5 + tools/virt-qmp-proxy | 360 +++++++++++++++++++++++++++++++ 4 files changed, 486 insertions(+) create mode 100644 docs/manpages/virt-qmp-proxy.rst create mode 100755 tools/virt-qmp-proxy diff --git a/docs/manpages/meson.build b/docs/manpages/meson.build index ba673cf472..4162a9969a 100644 --- a/docs/manpages/meson.build +++ b/docs/manpages/meson.build @@ -18,6 +18,7 @@ docs_man_files = [ { 'name': 'virt-pki-query-dn', 'section': '1', 'install': true }, { 'name': 'virt-pki-validate', 'section': '1', 'install': true }, { 'name': 'virt-qemu-run', 'section': '1', 'install': conf.has('WITH_QEMU') }, + { 'name': 'virt-qmp-proxy', 'section': '1', 'install': conf.has('WITH_QEMU') }, { 'name': 'virt-xml-validate', 'section': '1', 'install': true }, { 'name': 'libvirt-guests', 'section': '8', 'install': conf.has('WITH_LIBVIRTD') }, diff --git a/docs/manpages/virt-qmp-proxy.rst b/docs/manpages/virt-qmp-proxy.rst new file mode 100644 index 0000000000..30b9f6699d --- /dev/null +++ b/docs/manpages/virt-qmp-proxy.rst @@ -0,0 +1,120 @@ +============== +virt-qmp-proxy +============== + +-------------------------------------------------- +Expose a QMP proxy server for a libvirt QEMU guest +-------------------------------------------------- + +:Manual section: 1 +:Manual group: Virtualization Support + +.. contents:: + + +SYNOPSIS +======== + +``virt-qmp-proxy`` [*OPTION*]... *DOMAIN* *QMP-SOCKET-PATH* + + +DESCRIPTION +=========== + +This tool provides a way to expose a QMP proxy server that communicates +with a QEMU guest managed by libvirt. This enables standard QMP client +tools to interact with libvirt managed guests. + +**NOTE: use of this tool will result in the running QEMU guest being +marked as tainted.** It is strongly recommended that this tool *only be +used to send commands which query information* about the running guest. +If this tool is used to make changes to the state of the guest, this +may have negative interactions with the QEMU driver, resulting in an +inability to manage the guest operation thereafter, and in the worst +case **potentially lead to data loss or corruption**. + +The ``virt-qmp-proxy`` program will listen on a UNIX socket for incoming +client connections, and run the QMP protocol over the connection. Any +commands received will be sent to the running libvirt guest, and replies +sent back. + +The ``virt-qemu-proxy`` program may be interrupted (eg Ctrl-C) when it +is no longer required. The libvirt QEMU guest will continue running. + + +OPTIONS +======= + +*DOMAIN* + +The ID or UUID or Name of the libvirt QEMU guest. + +*QMP-SOCKET-PATH* + +The filesystem path at which to run the QMP server, listening for +incoming connections. + +``-c`` *CONNECTION-URI* +``--connect``\ =\ *CONNECTION-URI* + +The URI for the connection to the libvirt QEMU driver. If omitted, +a URI will be auto-detected. + +``-v``, ``--verbose`` + +Run in verbose mode, printing all QMP commands and replies that +are handled. + +``-h``, ``--help`` + +Display the command line help. + + +EXIT STATUS +=========== + +Upon successful shutdown, an exit status of 0 will be set. Upon +failure a non-zero status will be set. + + +AUTHOR +====== + +Daniel P. Berrangé + + +BUGS +==== + +Please report all bugs you discover. This should be done via either: + +#. the mailing list + + `https://libvirt.org/contact.html <https://libvirt.org/contact.html>`_ + +#. the bug tracker + + `https://libvirt.org/bugs.html <https://libvirt.org/bugs.html>`_ + +Alternatively, you may report bugs to your software distributor / vendor. + +COPYRIGHT +========= + +Copyright (C) 2022 by Red Hat, Inc. + + +LICENSE +======= + +``virt-qemu-proxy`` is distributed under the terms of the GNU LGPL v2+. +This is free software; see the source for copying conditions. There +is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR +PURPOSE + + +SEE ALSO +======== + +virsh(1), `https://libvirt.org/ <https://libvirt.org/>`_, +`QMP reference <https://www.qemu.org/docs/master/interop/qemu-qmp-ref.html>`_ diff --git a/tools/meson.build b/tools/meson.build index bb28a904dc..4e959ecf0b 100644 --- a/tools/meson.build +++ b/tools/meson.build @@ -320,6 +320,11 @@ if conf.has('WITH_LIBVIRTD') endif endif +if conf.has('WITH_QEMU') + install_data('virt-qmp-proxy', + install_dir: bindir) +endif + if bash_completion_dep.found() subdir('bash-completion') endif diff --git a/tools/virt-qmp-proxy b/tools/virt-qmp-proxy new file mode 100755 index 0000000000..d85342bd2b --- /dev/null +++ b/tools/virt-qmp-proxy @@ -0,0 +1,360 @@ +#!/usr/bin/env python3 + +import argparse +import array +import libvirt +import libvirt_qemu +import os +import re +import socket +import sys +import traceback +import json +import fcntl + + +debug = False + +def get_domain(uri, domstr): + conn = libvirt.open(uri) + + dom = None + saveex = None + + def try_lookup(cb): + try: + return cb() + except libvirt.libvirtError as ex: + nonlocal saveex + if saveex is None: + saveex = ex + + if re.match(r'^\d+$', domstr): + dom = try_lookup(lambda: conn.lookupByID(int(domstr))) + + if dom is None and re.match(r'^[-a-f0-9]{36}|[a-f0-9]{32}$', domstr): + dom = try_lookup(lambda: conn.lookupByUUIDString(domstr)) + + if dom is None: + dom = try_lookup(lambda: conn.lookupByName(domstr)) + + if dom is None: + raise saveex + + if not dom.isActive(): + raise Exception("Domain must be running to use QMP") + + return conn, dom + + +class QMPProxy(object): + + def __init__(self, conn, dom, serversock, verbose): + self.conn = conn + self.dom = dom + self.verbose = verbose + + self.serversock = serversock + self.serverwatch = 0 + + self.clientsock = None + self.clientwatch = 0 + + self.api2sock = bytes([]) + self.api2sockfds = [] + + self.sock2api = bytes([]) + self.sock2apifds = [] + + self.serverwatch = libvirt.virEventAddHandle( + self.serversock.fileno(), libvirt.VIR_EVENT_HANDLE_READABLE, + self.handle_server_io, self) + + libvirt_qemu.qemuMonitorEventRegister(self.conn, self.dom, + None, + self.handle_qmp_event, + self) + + + @staticmethod + def handle_qmp_event(conn, dom, event, secs, usecs, details, self): + evdoc = { + "event": event, + "timestamp": {"seconds": secs, "microseconds": usecs } + } + if details is not None: + evdoc["data"] = details + + ev = json.dumps(evdoc) + if self.verbose: + print(ev) + ev += "\r\n" + self.api2sock += ev.encode("utf-8") + self.update_client_events() + + + def recv_with_fds(self): + # Match VIR_NET_MESSAGE_NUM_FDS_MAX in virnetprotocol.x + maxfds = 32 + fds = array.array('i') + cmsgdatalen = socket.CMSG_LEN(maxfds * fds.itemsize) + + data, cmsgdata, flags, addr = self.clientsock.recvmsg(1024, + cmsgdatalen) + for cmsg_level, cmsg_type, cmsg_data in cmsgdata: + if (cmsg_level == socket.SOL_SOCKET and + cmsg_type == socket.SCM_RIGHTS): + fds.frombytes(cmsg_data[:len(cmsg_data) - + (len(cmsg_data) % fds.itemsize)]) + else: + raise Exception("Unexpected CMSGDATA level %d type %d" % ( + cmsg_level, cmsg_type)) + + return data, [self.make_file(fd) for fd in fds] + + + def send_with_fds(self, data, fds): + cfds = [fd.fileno() for fd in fds] + + cmsgdata = [(socket.SOL_SOCKET, socket.SCM_RIGHTS, + array.array("i", cfds))] + + return self.clientsock.sendmsg([data], cmsgdata) + + + @staticmethod + def make_file(fd): + flags = fcntl.fcntl(fd, fcntl.F_GETFL) + + mask = os.O_RDONLY | os.O_WRONLY | os.O_RDWR | os.O_APPEND + flags = flags & mask + mode = "" + if flags == os.O_RDONLY: + mode = "rb" + elif flags == os.O_WRONLY: + mode = "wb" + elif flags == os.O_RDWR: + mode = "r+b" + elif flags == (os.O_WRONLY | os.O_APPEND): + mode = "ab" + elif flags == (os.O_RDWR | os.O_APPEND): + mode = "a+b" + + return os.fdopen(fd, mode) + + + def add_client(self, sock): + ver = self.conn.getVersion() + major = int(ver / 1000000) % 1000 + minor = int(ver / 1000) % 1000 + micro = ver % 1000 + + greetingobj = { + "QMP": { + "version": { + "qemu": { + "major": major, + "minor": minor, + "micro": micro, + }, + "package": f"qemu-{major}.{minor}.{micro}", + }, + "capabilities": [ + "oob" + ], + } + } + greeting = json.dumps(greetingobj) + if self.verbose: + print(greeting) + greeting += "\r\n" + + self.clientsock = sock + self.clientwatch = libvirt.virEventAddHandle( + self.clientsock.fileno(), libvirt.VIR_EVENT_HANDLE_WRITABLE, + self.handle_client_io, self) + self.api2sock += greeting.encode("utf-8") + self.update_server_events() + + + def remove_client(self): + libvirt.virEventRemoveHandle(self.clientwatch) + self.clientsock.close() + self.clientsock = None + self.clientwatch = 0 + self.update_server_events() + + self.api2sock = bytes([]) + self.api2sockfds = [] + + self.sock2api = bytes([]) + self.sock2apifds = [] + + + def update_client_events(self): + # For simplicity of tracking distinct QMP cmds and their passed FDs + # we don't try to support "pipelining", only a single cmd may be + # inflight + if len(self.api2sock) > 0: + events = libvirt.VIR_EVENT_HANDLE_WRITABLE + else: + events = libvirt.VIR_EVENT_HANDLE_READABLE + + libvirt.virEventUpdateHandle(self.clientwatch, events) + + + def update_server_events(self): + if self.clientsock is not None: + libvirt.virEventUpdateHandle(self.serverwatch, 0) + else: + libvirt.virEventUpdateHandle(self.serverwatch, + libvirt.VIR_EVENT_HANDLE_READABLE) + + + def try_command(self): + try: + cmdstr = self.sock2api.decode("utf-8") + cmd = json.loads(cmdstr) + + if self.verbose: + cmdstr = cmdstr.strip() + print(cmdstr) + except Exception as ex: + if debug: + print("Incomplete %s: %s" % ( self.sock2api, ex)) + return + + id = None + if "id" in cmd: + id = cmd["id"] + del cmd["id"] + + if cmd.get("execute", "") == "qmp_capabilities": + resobj = { + "return": {}, + } + resfds = [] + else: + if hasattr(libvirt_qemu, "qemuMonitorCommandWithFiles"): + res, resfds = libvirt_qemu.qemuMonitorCommandWithFiles( + self.dom, json.dumps(cmd), [f.fileno() for f in self.sock2apifds]) + resobj = json.loads(res) + else: + if len(self.sock2apifds) > 0: + raise Exception("FD passing not supported") + res = libvirt_qemu.qemuMonitorCommand( + self.dom, json.dumps(cmd)) + resfds = [] + resobj = json.loads(res) + + if "id" in resobj: + del resobj["id"] + if id is not None: + resobj["id"] = id + + res = json.dumps(resobj) + if self.verbose: + print(res) + res += "\r\n" + + self.sock2api = bytes([]) + self.sock2apifds = [] + self.api2sock += res.encode("utf-8") + self.api2sockfds = resfds + + + @staticmethod + def handle_client_io(watch, fd, events, self): + error = False + try: + if events & libvirt.VIR_EVENT_HANDLE_WRITABLE: + done = self.send_with_fds(self.api2sock, self.api2sockfds) + if done > 0: + self.api2sock = self.api2sock[done:] + self.api2sockfds = [] + elif events & libvirt.VIR_EVENT_HANDLE_READABLE: + data, fds = self.recv_with_fds() + if len(data) == 0: + error = True + else: + self.sock2api += data + if len(fds): + self.sock2apifds += fds + + self.try_command() + else: + error = True + except Exception as e: + global debug + if debug: + print("%s: %s" % (sys.argv[0], str(e))) + print(traceback.format_exc()) + error = True + + if error: + self.remove_client() + else: + self.update_client_events() + + + @staticmethod + def handle_server_io(watch, fd, events, self): + if self.clientsock is None: + sock, addr = self.serversock.accept() + self.add_client(sock) + else: + self.update_server_events() + + +def parse_commandline(): + parser = argparse.ArgumentParser(description="Libvirt QMP proxy") + parser.add_argument("--connect", "-c", + help="Libvirt QEMU driver connection URI") + parser.add_argument("--debug", "-d", action='store_true', + help="Display debugging information") + parser.add_argument("--verbose", "-v", action='store_true', + help="Display QMP traffic") + parser.add_argument("domain", metavar="DOMAIN", + help="Libvirt guest domain ID/UUID/Name") + parser.add_argument("sockpath", metavar="QMP-SOCK-PATH", + help="UNIX socket path for QMP server") + + return parser.parse_args() + + +def main(): + args = parse_commandline() + global debug + debug = args.debug + + if not debug: + libvirt.registerErrorHandler(lambda opaque, error: None, None) + + libvirt.virEventRegisterDefaultImpl() + + conn, dom = get_domain(args.connect, args.domain) + + if conn.getType() != "QEMU": + raise Exception("QMP proxy requires a QEMU driver connection not %s" % + conn.getType()) + + sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) + if os.path.exists(args.sockpath): + os.unlink(args.sockpath) + sock.bind(args.sockpath) + sock.listen(1) + + proxy = QMPProxy(conn, dom, sock, args.verbose) + + while True: + libvirt.virEventRunDefaultImpl() + + +try: + main() + sys.exit(0) +except Exception as e: + print("%s: %s" % (sys.argv[0], str(e))) + if debug: + print(traceback.format_exc()) + sys.exit(1) -- 2.36.1

3 2

[PATCH] security_selinux.c: Relabel existing mode="bind" UNIX sockets
by David Michael 01 Jul '22

01 Jul '22

This supports sockets created by libvirt and passed by FD using the same method as in security_dac.c. Signed-off-by: David Michael <david(a)bigbadwolfsecurity.com> --- Hi, Custom SELinux labels are not applied to sockets when they have mode="bind", but other security models (DAC) allow changing these sockets. Can the same method be used to support SELinux? Thanks. David src/security/security_selinux.c | 6 ++++-- tests/securityselinuxlabeldata/chardev.txt | 2 +- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/src/security/security_selinux.c b/src/security/security_selinux.c index e2f34a27dc..8b258c9e36 100644 --- a/src/security/security_selinux.c +++ b/src/security/security_selinux.c @@ -2541,7 +2541,9 @@ virSecuritySELinuxSetChardevLabel(virSecurityManager *mgr, break; case VIR_DOMAIN_CHR_TYPE_UNIX: - if (!dev_source->data.nix.listen) { + if (!dev_source->data.nix.listen || + (dev_source->data.nix.path && + virFileExists(dev_source->data.nix.path))) { if (virSecuritySELinuxSetFilecon(mgr, dev_source->data.nix.path, imagelabel, @@ -2618,7 +2620,7 @@ virSecuritySELinuxRestoreChardevLabel(virSecurityManager *mgr, case VIR_DOMAIN_CHR_TYPE_UNIX: if (!dev_source->data.nix.listen) { if (virSecuritySELinuxRestoreFileLabel(mgr, - dev_source->data.file.path, + dev_source->data.nix.path, true) < 0) goto done; } diff --git a/tests/securityselinuxlabeldata/chardev.txt b/tests/securityselinuxlabeldata/chardev.txt index 3f4b6302b9..bdb367f7a5 100644 --- a/tests/securityselinuxlabeldata/chardev.txt +++ b/tests/securityselinuxlabeldata/chardev.txt @@ -2,6 +2,6 @@ /plain.dev;system_u:object_r:svirt_image_t:s0:c41,c264 /plain.fifo;system_u:object_r:svirt_image_t:s0:c41,c264 /nolabel.sock; -/plain.sock; +/plain.sock;system_u:object_r:svirt_image_t:s0:c41,c264 /yeslabel.sock;system_u:object_r:svirt_image_t:s0:c41,c264 /altlabel.sock;system_u:object_r:svirt_image_custom_t:s0:c41,c264 -- 2.36.1

4 7