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[libvirt] [PATCH 2/5] macvtap support for libvirt -- parse new interface XML
by Stefan Berger 08 Feb '10

08 Feb '10

This part adds support to domain_conf.{c|h} for parsing the new interface XML of type 'direct'. Signed-off-by: Stefan Berger <stefanb(a)us.ibm.com>

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[libvirt] [PATCH 4/5] macvtap support for libvirt -- helper code
by Stefan Berger 08 Feb '10

08 Feb '10

This part adds the helper code to setup and tear down macvtap devices using direct communication with the device driver via netlink sockets. Signed-off-by: Stefan Berger <stefanb(a)us.ibm.com>

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[libvirt] RFC: solving problem with qemu domain save on root-squashing NFS
by Laine Stump 08 Feb '10

08 Feb '10

(I had sent this message last week as a response to a message in a patch thread, but thought today that possibly some mail readers would bury it, so I'm sending it again disconnected from any existing thread. I can send the patches I mention below to anyone interested in playing around with them, but they're not useful since they still fail at the final step...) On 01/24/2010 11:57 AM, Dan Kenigsberg wrote: > On Wed, Jan 20, 2010 at 03:14:57PM +0000, Daniel P. Berrange wrote: >> This patch series does some work on te security drivers, and the QEMU >> code >> for managing DAC permissions on files. >> >> The core goal is to turn the QEMU driver DAC file management code into a >> security driver. Instead of QEMU calling into the SELinux/AppArmour >> drivers >> directly, a stacked driver module is introduced. This delegates all >> operations >> to first the QEMU DAC driver, and then the main SELinux/AppArmour >> driver. >> The end result is that all the permissions management code is removed >> from >> the QEMU driver, and we're left with just simple security driver calls. >> >> In the process of this a number of flaws in the current hotplug code >> were >> found, and code was generally tidied up with a view to making it >> easier to >> manage. >> >> Finally, we add the ability to turn off the QEMU DAC file managment >> code, >> and also deal gracefully with failures to change ownership (eg on NFS >> with >> root squash, or readonly FS). > Thanks for this series. However, it seems that we still have a problem > when trying to save domain to a root-squashing nfs export. > When using qemu directly, as a user with write permissions to that > export, there is no problem. When using libvirt, libvirt tries to write > its own state to the target file. I would not want to pre-create the > target file as world redable. > > How about performing open(path, O_CREAT|O_TRUNC|O_WRONLY, > S_IRUSR|S_IWUSR)) with the euid of the qemu process? I came up with a patch that creates the domain state file by first forking, followed by the child process doing setuid(qemu) and all the write-to-the-file stuff that creates the file (similar to the recent virFileCreate patch). This works all the way up through qemu's appending its state onto the file. The trouble comes when qemudDomainSave calls securityDriver->domainRestoreSavedStateLabel() (in this case, qemuSecurityStackedRestoreSavedStateLabel()). That function first calls the primary security driver's qemuSecurityDACRestoreSavedStateLabel(), which will fail because it attempts to chown the file to 0,0 (to prevent other qemu instances from messing with it). That can be disabled by setting "dynamic_ownership=0" in qemu.conf (needed in several other places when stuff is stored on root-squashing NFS anyway :-/). Then the stacked security driver calls the secondary security driver's SELinuxRestoreSavedStateLabel(), which also fails because of an SELinux function (matchpathcon) returning failure. We could ignore this failure, but that would create an unnecessary security hole for all those installations that *aren't* storing their domains on root-squashing NFS. So I *think* what I'm looking for a good way to avoid the SELinux stuff when the destination file is located on a root-squashing NFS share, but not ignore it otherwise (I believe the consensus is that we *don't* want to require another configuration knob if at all possible, since that would not only lead to extra complexity of config, but also to uninformed users turning it off when not necessary). Does anyone have any good ideas for doing this (or for a different approach)? (I suppose I could always attempt the entire operation assuming not, then redo with fork/setuid if the first attempt failed, but that seems less than elegant).

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[libvirt] Live migration woes
by Thomas Treutner 08 Feb '10

08 Feb '10

Hi, is anyone using libvirt-git and qemu-kvm post-0.11 and can live migrate VMs successfully for- and backwards? qemu-kvm-0.11 seems to be the latest release were live migration works, and I'm trying to figure out if its a kvm or libvirt problem, since there were other things (balloon parameter f.e.) that were changed with qemu-kvm-0.12 and caused troubles when using libvirt. thx,t

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[libvirt] Regarding lxc driver for libvirt.
by Kumar L Srikanth-B22348 08 Feb '10

08 Feb '10

Hi, I am new to libvirt. I want to create a Domain using libvirt XML. In order to mount the host's '/home/srikanth' directory to the new container's '/' directory, my XML format is shown below: <domain type='lxc' id='1'> <name>container1_vm</name> <memory>500000</memory> <os> <type>exe</type> <init>/bin/sh</init> </os> <vcpu>1</vcpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/libexec/libvirt_lxc</emulator> <filesystem type='mount'> <source dir='/home/srikanth'/> <target dir='/'/> </filesystem> <console type='pty' /> </devices> </domain> With the above libvirt XML, Domain is defining, but not starting. When I issue the start command it's saying "Domain started", but showing "shut off" status. If I changed the target directory(<traget dir='/'/>) from '/' to '/home/container1'(<traget dir='/home/container1'/>), the domain is starting normally and I am able to see the contents in the target directory. Can you please let me know, how can I set the target directory to '/'? By the way, I am using libvirt version o.7.6. Regards, Srikanth.

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[libvirt] [PATCH UPDATE] Add support for virtio channel
by Matthew Booth 08 Feb '10

08 Feb '10

Amit pointed out that byte_limit, guest_byte_limit and cache_buffers are now gone. They are removed in these updated patches.

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[libvirt] FYI, [PATCH] build: update gnulib submodule to latest
by Jim Meyering 05 Feb '10

05 Feb '10

FYI, I've just pushed this: >From 26bd7bef58296300cd81756297de514b9c2073df Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyering(a)redhat.com> Date: Fri, 5 Feb 2010 17:57:39 +0100 Subject: [PATCH] build: update gnulib submodule to latest * .gnulib: This fixes a warning in test-gettimeofday.c, seen via "make check". Reported by Daniel Veillard. --- .gnulib | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/.gnulib b/.gnulib index 9d0ad65..11fbc57 160000 --- a/.gnulib +++ b/.gnulib @@ -1 +1 @@ -Subproject commit 9d0ad652de159d08e5f679842f8a2a5658196361 +Subproject commit 11fbc57405a118e6ec9a3ebc19bbf5ececdae4d6 -- 1.7.0.rc1.204.gb96e

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[libvirt] FW: Regarding lxc driver for libvirt.
by Kumar L Srikanth-B22348 05 Feb '10

05 Feb '10

Can anyone help in the below issue? Regards, Srikanth. -----Original Message----- From: Kumar L Srikanth-B22348 Sent: Friday, February 05, 2010 4:02 PM To: 'libvir-list(a)redhat.com' Subject: Regarding lxc driver for libvirt. Hi, I am new to libvirt. I want to create a Domain using libvirt XML. In order to mount the host's '/home/srikanth' directory to the new container's '/' directory, my XML format is shown below: <domain type='lxc' id='1'> <name>container1_vm</name> <memory>500000</memory> <os> <type>exe</type> <init>/bin/sh</init> </os> <vcpu>1</vcpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/libexec/libvirt_lxc</emulator> <filesystem type='mount'> <source dir='/home/srikanth'/> <target dir='/'/> </filesystem> <console type='pty' /> </devices> </domain> With the above libvirt XML, Domain is defining, but not starting. When I issue the start command it's saying "Domain started", but showing "shut off" status. If I changed the target directory(<traget dir='/'/>) from '/' to '/home/container1'(<traget dir='/home/container1'/>), the domain is starting normally and I am able to see the contents in the target directory. Can you please let me know, how can I set the target directory to '/'? By the way, I am using libvirt version o.7.6. Regards, Srikanth.

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[libvirt] [PATCH] absolutePathFromBaseFile: don't leak when first arg contains no "/"
by Jim Meyering 05 Feb '10

05 Feb '10

Not only did this function leak(p), but it would also over-allocate (by the length of basename(base_file)), and then later, re-alloc to compensate, so I rewrote it: >From 1dc52930daa000b407d8a8f18588a19cf4e8b7f5 Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyering(a)redhat.com> Date: Thu, 4 Feb 2010 16:55:57 +0100 Subject: [PATCH] absolutePathFromBaseFile: don't leak when first arg contains no "/" * src/util/storage_file.c: Include "dirname.h". (absolutePathFromBaseFile): Rewrite not to leak, and to require fewer allocations. * bootstrap (modules): Add dirname-lgpl and stpncpy. * .gnulib: Update submodule to the latest. --- .gnulib | 2 +- bootstrap | 2 ++ src/util/storage_file.c | 27 ++++++++++----------------- 3 files changed, 13 insertions(+), 18 deletions(-) diff --git a/.gnulib b/.gnulib index 146d914..9d0ad65 160000 --- a/.gnulib +++ b/.gnulib @@ -1 +1 @@ -Subproject commit 146d9145073e62a2096a2d6b33f75e93908fedf3 +Subproject commit 9d0ad652de159d08e5f679842f8a2a5658196361 diff --git a/bootstrap b/bootstrap index cc3c6ef..5cc43c5 100755 --- a/bootstrap +++ b/bootstrap @@ -71,6 +71,7 @@ c-ctype canonicalize-lgpl close connect +dirname-lgpl getaddrinfo gethostname getpass @@ -93,6 +94,7 @@ send setsockopt socket stpcpy +stpncpy strchrnul strndup strerror diff --git a/src/util/storage_file.c b/src/util/storage_file.c index 44057d2..8c53fba 100644 --- a/src/util/storage_file.c +++ b/src/util/storage_file.c @@ -1,7 +1,7 @@ /* * storage_file.c: file utility functions for FS storage backend * - * Copyright (C) 2007-2009 Red Hat, Inc. + * Copyright (C) 2007-2010 Red Hat, Inc. * Copyright (C) 2007-2008 Daniel P. Berrange * * This library is free software; you can redistribute it and/or @@ -26,6 +26,7 @@ #include <unistd.h> #include <fcntl.h> +#include "dirname.h" #include "memory.h" #include "virterror_internal.h" @@ -246,26 +247,18 @@ vmdk4GetBackingStore(virConnectPtr conn, static char * absolutePathFromBaseFile(const char *base_file, const char *path) { - size_t base_size, path_size; - char *res, *p; + char *res; + size_t d_len = dir_len (base_file); - if (*path == '/') + /* If path is already absolute, or if dirname(base_file) is ".", + just return a copy of path. */ + if (*path == '/' || d_len == 0) return strdup(path); - base_size = strlen(base_file) + 1; - path_size = strlen(path) + 1; - if (VIR_ALLOC_N(res, base_size - 1 + path_size) < 0) + if (VIR_ALLOC_N(res, d_len + 1 + strlen(path) + 1) < 0) return NULL; - memcpy(res, base_file, base_size); - p = strrchr(res, '/'); - if (p != NULL) - p++; - else - p = res; - memcpy(p, path, path_size); - if (VIR_REALLOC_N(res, (p + path_size) - res) < 0) { - /* Ignore failure */ - } + + stpcpy(stpcpy(stpncpy(res, base_file, d_len), "/"), path); return res; } -- 1.7.0.rc1.199.g9253a

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[libvirt] [PATCH 0/12] Improve security driver handling & QEMU DAC management
by Daniel P. Berrange 05 Feb '10

05 Feb '10

This patch series does some work on te security drivers, and the QEMU code for managing DAC permissions on files. The core goal is to turn the QEMU driver DAC file management code into a security driver. Instead of QEMU calling into the SELinux/AppArmour drivers directly, a stacked driver module is introduced. This delegates all operations to first the QEMU DAC driver, and then the main SELinux/AppArmour driver. The end result is that all the permissions management code is removed from the QEMU driver, and we're left with just simple security driver calls. In the process of this a number of flaws in the current hotplug code were found, and code was generally tidied up with a view to making it easier to manage. Finally, we add the ability to turn off the QEMU DAC file managment code, and also deal gracefully with failures to change ownership (eg on NFS with root squash, or readonly FS).

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