virt-install: Make missing --osinfo fatal for most cases

This was previously discussed here:
https://listman.redhat.com/archives/virt-tools-list/2020-September/msg00017.html

For the x86 + hvm case, failure to specify an --osinfo/--os-variant
OS, and failure to detect an OS from install media, will now throw
a big error:

```
--os-variant/--osinfo OS name is required, but no value was
set or detected.

This is now a fatal error. Specifying an OS name is required
for modern, performant, and secure virtual machine defaults.

If you expected virt-install to detect an OS name from the
install media, you can set a fallback OS name with:

  --osinfo detect=on,name=OSNAME

You can see a full list of possible OS name values with:

   virt-install --osinfo list

If your Linux distro is not listed, try one of generic values
such as: linux2020, linux2018, linux2016

If you just need to get the old behavior back, you can use:

  --osinfo detect=on,require=off

Or export VIRTINSTALL_OSINFO_DISABLE_REQUIRE=1
```

The thread goes into more detail, but basically, for x86 VMs at least,
it's unlikely you will _ever_ want the default 'generic' behavior,
which gives gives no virtio, no PCIe, no usb3, IDE disks, slow
network devices, etc.

Many people use virt-install in scripts and CI, and this may now
cause breakage. The environment variable is there to help them
get things back to normal as quick as possible, but it will still
noisy up their logs with the warning to hopefully get them to make
a useful change to their virt-install invocations.

This is limited to x86, since that's where most of our defaults
historically differ, and where we can depend on libosinfo to give
the most accurate device info. This may be relevant to change for
other KVM architectures in the future.

Signed-off-by: Cole Robinson <crobinso@redhat.com>

man/virt-install.rst

@@ -48,7 +48,7 @@ argument, example: virt-install --disk=?
 
 Most options are not required. If a suitable --osinfo value is specified
 or detected, all defaults will be filled in and reported in the terminal
-output. If an --osinfo is not specified. minimum required options are --memory,
+output. Otherwise, minimum required options are --memory,
 guest storage (--disk or --filesystem), and an install method choice.
 
 
@@ -974,14 +974,13 @@ GUEST OS OPTIONS
 ``--os-variant``, ``--osinfo``
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-**Syntax:** ``--osinfo`` [OS_VARIANT|OPT1=VAL1,...]
+**Syntax:** ``--osinfo`` [OSNAME|OPT1=VAL1,...]
 
-Optimize the guest configuration for a specific operating system (ex.
+Optimize the guest configuration for a specific operating system.
-'fedora29', 'rhel7', 'win10'). While not required, specifying this
+For most cases, an OS must be specified or detected from the install
-options is HIGHLY RECOMMENDED, as it can greatly increase performance
+media so performance critical features like virtio can be enabled.
-by specifying virtio among other guest tweaks.
 
-The simplest usage is ``--os-variant OS-NAME`` or ``--osinfo OS-NAME``,
+The simplest usage is ``--os-variant OSNAME`` or ``--osinfo OSNAME``,
 for example ``--osinfo fedora32``. The supported suboptions are:
 
 ``name=``, ``short-id=``
@@ -1012,17 +1011,23 @@ Some interesting examples:
     Attempt OS detection from install media, but if that fails, use
     OSNAME as a fallback.
 
-
-By default, virt-install will do ``--osinfo detect=on,name=generic``,
-using the detected OS if found, and falling back to the stub ``generic``
-value otherwise, and printing a warning.
-
 If any manual ``--osinfo`` value is specified, the default is
-all settings off or unset.
+all other settings off or unset.
+
+By default, virt-install will always attempt ``--osinfo detect=on``
+for appropriate install media. If no OS is detected, we will fail
+in certain common cases (x86 KVM for example). This fatal error was
+added in 2022. You can work around this by using the fallback example
+above, or disabling the ``require`` option. If you just need to get back
+to the old non-fatal behavior ASAP, set the environment variable
+VIRTINSTALL_OSINFO_DISABLE_REQUIRE=1.
 
 Use the command ``virt-install --osinfo list`` to get the list of the
 accepted OS variants. See ``osinfo-query os`` for even more output.
 
+Note: ``--os-variant`` and ``--osinfo`` are aliases for one another.
+``--osinfo`` is the preferred new style naming.
+
 
 
 STORAGE OPTIONS

tests/test_cli.py

@@ -771,7 +771,7 @@ source.reservations.managed=no,source.reservations.source.type=unix,source.reser
 # Boot install options #
 ########################
 
-c = vinst.add_category("boot", "--nographics --noautoconsole --import --disk none --controller usb,model=none")
+c = vinst.add_category("boot", "--nographics --noautoconsole --import --disk none --controller usb,model=none --osinfo generic")
 c.add_compare("--boot loader=/path/to/loader,loader_secure=yes", "boot-loader-secure")
 c.add_compare("--boot firmware=bios,loader=/path/to/loader,loader.readonly=yes,loader.secure=no,loader.type=rom,bios.rebootTimeout=5000,bootmenu.enable=yes,bootmenu.timeout=5000", "boot-guest-loader-bios")
 c.add_compare("--boot firmware=efi,loader=/path/to/loader,loader.readonly=yes,loader.secure=yes,loader.type=pflash,bios.useserial=yes,nvram=/path/to/nvram", "boot-guest-loader-efi")
@@ -786,7 +786,7 @@ c.add_compare("--boot init=/bin/systemd,initargs='--unit emergency.service',init
 # CPU/RAM/numa and other singleton VM config tests #
 ####################################################
 
-c = vinst.add_category("cpuram", "--hvm --nographics --noautoconsole --nodisks --pxe")
+c = vinst.add_category("cpuram", "--hvm --nographics --noautoconsole --nodisks --pxe --osinfo generic")
 c.add_valid("--ram 4000000")  # Ram overcommit
 c.add_valid("--vcpus sockets=2,threads=2")  # Topology only
 c.add_valid("--cpuset 1,2,3")  # cpuset backcompat with no --vcpus specified
@@ -810,7 +810,7 @@ c.add_compare("--cpu model=core2duo,model.fallback=allow,model.vendor_id=Genuine
 # Storage provisioning #
 ########################
 
-c = vinst.add_category("storage", "--pxe --nographics --noautoconsole --hvm")
+c = vinst.add_category("storage", "--pxe --nographics --noautoconsole --hvm --osinfo detect=yes,require=no")
 c.add_valid("--disk path=%(EXISTIMG1)s")  # Existing disk, no extra options
 c.add_valid("--disk pool=default-pool,size=.0001 --disk pool=default-pool,size=.0001")  # Create 2 volumes in a pool
 c.add_valid("--disk vol=default-pool/testvol1.img")  # Existing volume
@@ -858,7 +858,7 @@ c.add_invalid("--disk size=1 --file foobar", grep="Cannot mix --file")  # --disk
 # Invalid devices that hit virtinst code paths #
 ################################################
 
-c = vinst.add_category("invalid-devices", "--noautoconsole --nodisks --pxe")
+c = vinst.add_category("invalid-devices", "--noautoconsole --nodisks --pxe --osinfo require=no")
 c.add_invalid("--connect %(URI-TEST-FULL)s --host-device 1d6b:2", grep="corresponds to multiple node devices")
 c.add_invalid("--connect %(URI-TEST-FULL)s --host-device pci_8086_2850_scsi_host_scsi_host", grep="Unsupported node device type 'scsi_host'")  # Unsupported hostdev type
 c.add_invalid("--host-device foobarhostdev", grep="Unknown hostdev address string format")  # Unknown hostdev
@@ -880,11 +880,8 @@ c.add_invalid("--memdev nvdimm,source.path=/path/to/nvdimm,target.size=2,target.
 ########################
 
 c = vinst.add_category("nodisk-install", "--nographics --noautoconsole --nodisks")
-c.add_valid("--hvm --cdrom %(EXISTIMG1)s")  # Simple cdrom install
+c.add_valid("--os-variant generic --pxe --ram 16", grep="Requested memory 16 MiB is abnormally low")  # catch low memory error
-c.add_valid("--pxe --ram 16", grep="Requested memory 16 MiB is abnormally low")  # catch low memory error
 c.add_valid("--os-variant winxp --ram 32 --cdrom %(EXISTIMG1)s", grep="32 MiB is less than the recommended 64 MiB")  # Windows. Catch memory warning
-c.add_valid("--pxe --virt-type test")  # Explicit virt-type
-c.add_valid("--arch i686 --pxe")  # Explicitly fullvirt + arch
 c.add_valid("--location location=%(TREEDIR)s")  # Directory tree URL install
 c.add_valid("--location %(TREEDIR)s --initrd-inject virt-install --extra-args ks=file:/virt-install")  # initrd-inject
 c.add_valid("--hvm --location %(TREEDIR)s --extra-args console=ttyS0")  # Directory tree URL install with extra-args
@@ -892,11 +889,11 @@ c.add_valid("--paravirt --location %(TREEDIR)s")  # Paravirt location
 c.add_valid("--location %(TREEDIR)s --os-variant fedora12")  # URL install with manual os-variant
 c.add_valid("--cdrom %(EXISTIMG2)s --os-variant win2k3")  # HVM windows install with disk
 c.add_valid("--cdrom %(EXISTIMG2)s --os-variant win2k3 --print-step 2")  # HVM windows install, print 3rd stage XML
-c.add_valid("--pxe --autostart")  # --autostart flag
+c.add_valid("--osinfo generic --pxe --autostart")  # --autostart flag
-c.add_compare("--cdrom http://example.com/path/to/some.iso", "cdrom-url")
+c.add_compare("--cdrom http://example.com/path/to/some.iso --os-variant detect=yes,require=no", "cdrom-url")
 c.add_compare("--pxe --print-step all --os-variant none", "simple-pxe")  # Diskless PXE install
 c.add_compare("--location ftp://example.com --os-variant auto", "fake-ftp")  # fake ftp:// install using urlfetcher.py mocking
-c.add_compare("--location https://foobar.com --os-variant detect=no", "fake-http")  # fake https:// install using urlfetcher.py mocking, but also hit --os-variant detect=no
+c.add_compare("--location https://foobar.com --os-variant detect=no,require=no", "fake-http")  # fake https:// install using urlfetcher.py mocking, but also hit --os-variant detect=no
 c.add_compare("--location https://foobar.com --os-variant detect=yes,name=win7", "os-detect-success-fallback")  # os detection succeeds, so fallback should be ignored
 c.add_compare("--pxe --os-variant detect=yes,name=win7", "os-detect-fail-fallback")  # os detection succeeds, so fallback should be ignored
 c.add_compare("--connect %(URI-KVM-X86)s --install fedora26", "osinfo-url")  # getting URL from osinfo
@@ -913,32 +910,33 @@ c.add_invalid("-c qemu:///system", grep="looks like a libvirt URI")  # error for
 c.add_invalid("--location /", grep="Error validating install location")  # detect_distro failure
 c.add_invalid("--os-variant id=foo://bar", grep="Unknown libosinfo ID")  # bad full id
 c.add_invalid("--location http://testsuitefail.com", grep="installable distribution")  # will trigger a particular mock failure
-
+c.add_invalid("--cdrom %(EXISTIMG2)s", grep="expected virt-install to detect")  # hits the missing --osinfo error
+c.add_invalid("--pxe", grep="linux2018, linux2016", nogrep="expected virt-install to detect")  # hits missing --osinfo error but doesn't trigger the bit about detectable media
 
 
 c = vinst.add_category("single-disk-install", "--nographics --noautoconsole --disk %(EXISTIMG1)s")
-c.add_valid("--hvm --import")  # FV Import install
+c.add_valid("--osinfo generic --hvm --install no_install=yes")  # import install equivalent
-c.add_valid("--hvm --install no_install=yes")  # import install equivalent
+c.add_valid("--osinfo generic --hvm --import --prompt --force")  # Working scenario w/ prompt shouldn't ask anything
-c.add_valid("--hvm --import --prompt --force")  # Working scenario w/ prompt shouldn't ask anything
 c.add_valid("--paravirt --import")  # PV Import install
 c.add_valid("--paravirt --print-xml 1")  # print single XML, implied import install
-c.add_valid("--hvm --import --wait 0", grep="Treating --wait 0 as --noautoconsole")  # --wait 0 is the same as --noautoconsole
+c.add_valid("--osinfo generic --hvm --import --wait 0", grep="Treating --wait 0 as --noautoconsole")  # --wait 0 is the same as --noautoconsole
 c.add_compare("-c %(EXISTIMG2)s --osinfo win2k3 --vcpus cores=4 --controller usb,model=none", "w2k3-cdrom")  # HVM windows install with disk
 c.add_compare("--connect %(URI-KVM-X86)s --install fedora26 --os-variant fedora27 --disk size=20", "osinfo-url-with-disk")  # filling in defaults, but with disk specified, and making sure we don't overwrite --os-variant
 c.add_compare("--connect %(URI-KVM-X86)s --pxe --os-variant short-id=debianbuster --disk none", "osinfo-multiple-short-id", prerun_check=lambda: not OSDB.lookup_os("debianbuster"))  # test plumbing for multiple short ids
-c.add_invalid("--hvm --import --wait 2", grep="exceeded specified time limit")  # --wait positive number, but test suite hack
+c.add_invalid("--osinfo generic --hvm --import --wait 2", grep="exceeded specified time limit")  # --wait positive number, but test suite hack
-c.add_invalid("--hvm --import --wait -1", grep="exceeded specified time limit")  # --wait -1, but test suite hack
+c.add_invalid("--osinfo generic --hvm --import --wait -1", grep="exceeded specified time limit")  # --wait -1, but test suite hack
-c.add_invalid("--hvm --import --wait", grep="exceeded specified time limit")  # --wait aka --wait -1, but test suite hack
+c.add_invalid("--osinfo generic --hvm --import --wait", grep="exceeded specified time limit")  # --wait aka --wait -1, but test suite hack
-c.add_invalid("--connect test:///default --name foo --ram 64 --disk none --sdl --hvm --import", use_default_args=False, grep="exceeded specified time limit")  # --sdl doesn't have a console callback, triggers implicit --wait -1
+c.add_invalid("--connect test:///default --name foo --ram 64 --disk none --sdl --osinfo generic --hvm --import", use_default_args=False, grep="exceeded specified time limit")  # --sdl doesn't have a console callback, triggers implicit --wait -1
 c.add_invalid("--paravirt --import --print-xml 2", grep="does not have XML step 2")  # PV Import install, no second XML step
 c.add_invalid("--paravirt --import --print-xml 7", grep="Unknown XML step request '7'")  # Invalid --print-xml arg
 c.add_invalid("--location kernel=foo,initrd=bar", grep="location kernel/initrd may only be specified with a location URL/path")
 c.add_invalid("--location http://example.com,kernel=foo", grep="location kernel/initrd must be be specified as a pair")
-c.add_valid("--pxe --os-type linux", grep="--os-type is deprecated")
+c.add_valid("--pxe --os-variant generic --os-type linux", grep="--os-type is deprecated")
 c.add_invalid("--os-variant solaris10 --unattended", grep="not support unattended")
 
+
 c = vinst.add_category("misc-install", "--nographics --noautoconsole")
-c.add_compare("--connect %s" % (utils.URIs.test_suite), "noargs-fail", use_default_args=False)  # No arguments
+c.add_compare("--connect %s --os-variant generic" % (utils.URIs.test_suite), "noargs-fail", use_default_args=False)  # No arguments
 c.add_compare("--connect %s --os-variant fedora26" % (utils.URIs.test_suite), "osvariant-noargs-fail", use_default_args=False)  # No arguments
 c.add_compare("--connect %s --os-variant fedora26 --pxe --print-xml" % (utils.URIs.test_suite), "osvariant-defaults-pxe", use_default_args=False)  # No arguments
 c.add_compare("--disk %(EXISTIMG1)s --os-variant fedora28 --cloud-init", "cloud-init-default")  # default --cloud-init behavior is root-password-generate=yes,disable=yes
@@ -949,16 +947,17 @@ c.add_compare("--disk %(EXISTIMG1)s --os-variant fedora28 --cloud-init user-data
 c.add_compare("--disk %(EXISTIMG1)s --os-variant fedora28 --cloud-init user-data=%(XMLDIR)s/cloudinit/user-data.txt,meta-data=%(XMLDIR)s/cloudinit/meta-data.txt,network-config=%(XMLDIR)s/cloudinit/network-config.txt", "cloud-init-options")  # --cloud-init user-data=,meta-data=,network-config=
 c.add_valid("--panic help --disk=? --check=help", grep="path_in_use")  # Make sure introspection doesn't blow up
 c.add_valid("--connect test:///default --test-stub-command", use_default_args=False)  # --test-stub-command
-c.add_valid("--nodisks --pxe", grep="VM performance may suffer")  # os variant warning
+c.add_valid("--nodisks --pxe --osinfo generic", grep="VM performance may suffer")  # os variant warning
+c.add_valid("--nodisks --pxe", env={"VIRTINSTALL_OSINFO_DISABLE_REQUIRE": "1"}, grep="Skipping fatal error")
 c.add_invalid("--hvm --nodisks --pxe foobar", grep="unrecognized arguments: foobar")  # Positional arguments error
-c.add_invalid("--nodisks --pxe --name test", grep="Guest name 'test' is already")  # Colliding name
+c.add_invalid("--nodisks --pxe --name test --osinfo require=no", grep="Guest name 'test' is already")  # Colliding name
-c.add_compare("--cdrom %(EXISTIMG1)s --disk size=1 --disk %(EXISTIMG2)s,device=cdrom", "cdrom-double")  # ensure --disk device=cdrom is ordered after --cdrom, this is important for virtio-win installs with a driver ISO
+c.add_compare("--osinfo generic --cdrom %(EXISTIMG1)s --disk size=1 --disk %(EXISTIMG2)s,device=cdrom", "cdrom-double")  # ensure --disk device=cdrom is ordered after --cdrom, this is important for virtio-win installs with a driver ISO
-c.add_valid("--connect %s --pxe --disk size=1" % utils.URIs.test_defaultpool_collision)  # testdriver already has a pool using the 'default' path, make sure we don't error
+c.add_valid("--connect %s --pxe --disk size=1 --osinfo generic" % utils.URIs.test_defaultpool_collision)  # testdriver already has a pool using the 'default' path, make sure we don't error
-c.add_compare("--connect %(URI-KVM-X86)s --reinstall test-clone-simple --pxe", "reinstall-pxe")  # compare --reinstall with --pxe
+c.add_compare("--connect %(URI-KVM-X86)s --reinstall test-clone-simple --pxe --osinfo generic", "reinstall-pxe")  # compare --reinstall with --pxe
 c.add_compare("--connect %(URI-KVM-X86)s --reinstall test-clone-simple --location http://example.com", "reinstall-location")  # compare --reinstall with --location
 c.add_compare("--reinstall test-cdrom --cdrom %(ISO-WIN7)s --unattended", "reinstall-cdrom")  # compare --reinstall with --cdrom handling
 c.add_invalid("--reinstall test --cdrom %(ISO-WIN7)s", grep="already active")  # trying to reinstall an active VM should fail
-c.add_invalid("--reinstall test", grep="install method must be specified")  # missing install method
+c.add_invalid("--reinstall test --osinfo none", grep="install method must be specified")  # missing install method
 c.add_valid("--osinfo list", grep="osinfo-query os")  # --osinfo list
 
 
@@ -987,7 +986,7 @@ c.add_invalid("--install fedora29 --unattended user-login=root", grep="as user-l
 # Remote URI specific tests #
 #############################
 
-c = vinst.add_category("remote", "--connect %(URI-TEST-REMOTE)s --nographics --noautoconsole")
+c = vinst.add_category("remote", "--connect %(URI-TEST-REMOTE)s --nographics --noautoconsole --osinfo generic")
 c.add_valid("--nodisks --pxe")  # Simple pxe nodisks
 c.add_valid("--cdrom %(EXISTIMG1)s --disk none --livecd --dry")  # remote cdrom install
 c.add_compare("--pxe "
@@ -1025,20 +1024,20 @@ c.add_compare("--connect " + utils.URIs.kvm_x86_session + " --disk size=8 --os-v
 c.add_valid("--connect " + utils.URIs.kvm_x86_session + " --install fedora21", prerun_check=has_old_osinfo)  # hits some get_search_paths and media_upload code paths
 
 # misc KVM config tests
-c.add_compare("--disk none --location %(ISO-NO-OS)s,kernel=frib.img,initrd=/frob.img", "location-manual-kernel", prerun_check=missing_xorriso)  # --location with an unknown ISO but manually specified kernel paths
+c.add_compare("--osinfo generic --disk none --location %(ISO-NO-OS)s,kernel=frib.img,initrd=/frob.img", "location-manual-kernel", prerun_check=missing_xorriso)  # --location with an unknown ISO but manually specified kernel paths
 c.add_compare("--disk %(EXISTIMG1)s --location %(ISOTREE)s --nonetworks", "location-iso", prerun_check=missing_xorriso)  # Using --location iso mounting
 c.add_compare("--disk %(EXISTIMG1)s --cdrom %(ISOLABEL)s", "cdrom-centos-label")  # Using --cdrom with centos CD label, should use virtio etc.
 c.add_compare("--disk %(EXISTIMG1)s --install bootdev=network --os-variant rhel5.4 --cloud-init none", "kvm-rhel5")  # RHEL5 defaults
 c.add_compare("--disk %(EXISTIMG1)s --install kernel=%(ISO-WIN7)s,initrd=%(ISOLABEL)s,kernel_args='foo bar' --os-variant rhel6.4 --unattended none", "kvm-rhel6")  # RHEL6 defaults. ISO paths are just to point at existing files
 c.add_compare("--disk %(EXISTIMG1)s --location https://example.com --install kernel_args='test overwrite',kernel_args_overwrite=yes --os-variant rhel7.0", "kvm-rhel7", precompare_check=no_osinfo_unattend_cb)  # RHEL7 defaults
 c.add_compare("--connect " + utils.URIs.kvm_x86_nodomcaps + " --disk %(EXISTIMG1)s --pxe --os-variant rhel7.0", "kvm-cpu-default-fallback", prerun_check=has_old_osinfo)  # No domcaps, so mode=host-model isn't safe, so we fallback to host-model-only
-c.add_compare("--connect " + utils.URIs.kvm_x86_nodomcaps + " --cpu host-copy --disk none --pxe", "kvm-hostcopy-fallback")  # No domcaps so need to use capabilities for CPU host-copy
+c.add_compare("--os-variant generic --connect " + utils.URIs.kvm_x86_nodomcaps + " --cpu host-copy --disk none --pxe", "kvm-hostcopy-fallback")  # No domcaps so need to use capabilities for CPU host-copy
 c.add_compare("--disk %(EXISTIMG1)s --pxe --os-variant centos7.0", "kvm-centos7", prerun_check=has_old_osinfo)  # Centos 7 defaults
 c.add_compare("--disk %(EXISTIMG1)s --pxe --os-variant centos7.0", "kvm-centos7", prerun_check=has_old_osinfo)  # Centos 7 defaults
 c.add_compare("--disk %(EXISTIMG1)s --cdrom %(EXISTIMG2)s --os-variant win10", "kvm-win10", prerun_check=has_old_osinfo)  # win10 defaults
 c.add_compare("--os-variant win7 --cdrom %(EXISTIMG2)s --boot loader_type=pflash,loader=CODE.fd,nvram_template=VARS.fd --disk %(EXISTIMG1)s", "win7-uefi", prerun_check=has_old_osinfo)  # no HYPER-V with UEFI
-c.add_compare("--arch i686 --boot uefi --install kernel=http://example.com/httpkernel,initrd=ftp://example.com/ftpinitrd --disk none", "kvm-i686-uefi")  # i686 uefi. piggy back it for --install testing too
+c.add_compare("--osinfo generic --arch i686 --boot uefi --install kernel=http://example.com/httpkernel,initrd=ftp://example.com/ftpinitrd --disk none", "kvm-i686-uefi")  # i686 uefi. piggy back it for --install testing too
-c.add_compare("--machine q35 --cdrom %(EXISTIMG2)s --disk %(EXISTIMG1)s", "q35-defaults")  # proper q35 disk defaults
+c.add_compare("--osinfo generic --machine q35 --cdrom %(EXISTIMG2)s --disk %(EXISTIMG1)s", "q35-defaults")  # proper q35 disk defaults
 c.add_compare("--disk size=1 --os-variant openbsd4.9", "openbsd-defaults")  # triggers net fallback scenario
 c.add_compare("--connect " + utils.URIs.kvm_x86_remote + " --import --disk %(EXISTIMG1)s --os-variant fedora21 --pm suspend_to_disk=yes", "f21-kvm-remote", prerun_check=has_old_osinfo)
 c.add_compare("--connect %(URI-KVM-X86)s --os-variant fedora26 --graphics spice --controller usb,model=none", "graphics-usb-disable")
@@ -1051,7 +1050,7 @@ c.add_invalid("--nodisks --boot network --arch mips --virt-type kvm", grep="any
 c.add_invalid("--nodisks --boot network --paravirt --arch mips", grep=" 'xen' for architecture 'mips'")
 
 
-c = vinst.add_category("kvm-x86_64-launch-security", "--disk none --noautoconsole")
+c = vinst.add_category("kvm-x86_64-launch-security", "--disk none --noautoconsole --osinfo generic")
 c.add_compare("--boot uefi --machine q35 --launchSecurity type=sev,reducedPhysBits=1,policy=0x0001,cbitpos=47,dhCert=BASE64CERT,session=BASE64SESSION,kernelHashes=yes --connect " + utils.URIs.kvm_amd_sev, "x86_64-launch-security-sev-full")  # Full cmdline
 c.add_compare("--boot uefi --machine q35 --launchSecurity sev --connect " + utils.URIs.kvm_amd_sev, "x86_64-launch-security-sev")  # Fill in platform data from domcaps
 c.add_valid("--boot uefi --machine q35 --launchSecurity sev,reducedPhysBits=1,cbitpos=47 --connect " + utils.URIs.kvm_amd_sev)  # Default policy == 0x0003 will be used
@@ -1061,7 +1060,7 @@ c.add_invalid("--boot uefi --launchSecurity sev --connect " + utils.URIs.kvm_amd
 c.add_invalid("--boot uefi --machine q35 --launchSecurity sev,policy=0x0001 --connect " + utils.URIs.kvm_x86_q35, grep="SEV launch security is not supported")  # Fail with no SEV capabilities
 
 
-c = vinst.add_category("kvm-q35", "--noautoconsole --connect " + utils.URIs.kvm_x86_q35)
+c = vinst.add_category("kvm-q35", "--noautoconsole --osinfo generic --connect " + utils.URIs.kvm_x86_q35)
 c.add_compare("--boot uefi --disk none", "boot-uefi")
 c.add_compare("--boot uefi --disk size=8 --tpm none", "boot-uefi-notpm")
 
@@ -1122,8 +1121,8 @@ c = vinst.add_category("xen", "--noautoconsole --connect " + utils.URIs.xen)
 c.add_valid("--disk %(EXISTIMG1)s --location %(TREEDIR)s --paravirt --graphics none")  # Xen PV install headless
 c.add_compare("--disk %(EXISTIMG1)s --import", "xen-default")  # Xen default
 c.add_compare("--disk %(EXISTIMG1)s --location %(TREEDIR)s --paravirt --controller xenbus,maxGrantFrames=64 --input default", "xen-pv", precompare_check="5.3.0")  # Xen PV
-c.add_compare("--disk  /iscsi-pool/diskvol1 --cdrom %(EXISTIMG1)s --livecd --hvm", "xen-hvm")  # Xen HVM
+c.add_compare("--osinfo generic --disk  /iscsi-pool/diskvol1 --cdrom %(EXISTIMG1)s --livecd --hvm", "xen-hvm")  # Xen HVM
-c.add_compare("--disk  /iscsi-pool/diskvol1 --cdrom %(EXISTIMG1)s --install no_install=yes --hvm", "xen-hvm")  # Ensure --livecd and --install no_install are essentially identical
+c.add_compare("--osinfo generic --disk  /iscsi-pool/diskvol1 --cdrom %(EXISTIMG1)s --install no_install=yes --hvm", "xen-hvm")  # Ensure --livecd and --install no_install are essentially identical
 
 
 
@@ -1133,8 +1132,8 @@ c.add_compare("--disk  /iscsi-pool/diskvol1 --cdrom %(EXISTIMG1)s --install no_i
 
 c = vinst.add_category("vz", "--noautoconsole --connect " + utils.URIs.vz)
 c.add_valid("--container")  # validate the special define+start logic
-c.add_valid("--hvm --cdrom %(EXISTIMG1)s --disk none")  # hit more install vz logic
+c.add_valid("--osinfo generic --hvm --cdrom %(EXISTIMG1)s --disk none")  # hit more install vz logic
-c.add_valid("--hvm --import --disk %(EXISTIMG1)s --noreboot")  # hit more install vz logic
+c.add_valid("--osinfo generic --hvm --import --disk %(EXISTIMG1)s --noreboot")  # hit more install vz logic
 c.add_invalid("--container --transient", grep="Domain type 'vz' doesn't support transient installs.")
 c.add_compare("""
 --container
@@ -1149,7 +1148,7 @@ c.add_compare("""
 ########################
 
 c = vinst.add_category("bhyve", "--name foobhyve --noautoconsole --connect " + utils.URIs.bhyve)
-c.add_compare("--boot uefi --disk none --ram 256 --pxe", "bhyve-uefi")
+c.add_compare("--osinfo generic --boot uefi --disk none --ram 256 --pxe", "bhyve-uefi")
 c.add_compare("--os-variant fedora27", "bhyve-default-f27")
 
 
@@ -1159,7 +1158,7 @@ c.add_compare("--os-variant fedora27", "bhyve-default-f27")
 # Device option back compat testing #
 #####################################
 
-c = vinst.add_category("device-back-compat", "--nodisks --pxe --noautoconsole")
+c = vinst.add_category("device-back-compat", "--nodisks --pxe --noautoconsole --paravirt")
 c.add_valid("--sdl")  # SDL
 c.add_valid("--vnc --keymap ja --vncport 5950 --vnclisten 1.2.3.4")  # VNC w/ lots of options
 c.add_valid("--sound")  # --sound with no option back compat
@@ -1174,13 +1173,14 @@ c.add_invalid("--mac 22:11:11:11:11:11", grep="in use by another virtual machine
 c.add_invalid("--graphics vnc --vnclisten 1.2.3.4", grep="Cannot mix --graphics and old style graphical options")
 c.add_invalid("--network user --bridge foo0", grep="Cannot use --bridge and --network at the same time")
 
-c = vinst.add_category("storage-back-compat", "--pxe --noautoconsole")
+c = vinst.add_category("storage-back-compat", "--pxe --noautoconsole --osinfo generic")
 c.add_valid("--file %(EXISTIMG1)s --nonsparse --file-size 4")  # Existing file, other opts
 c.add_valid("--file %(EXISTIMG1)s")  # Existing file, no opts
 c.add_valid("--file %(EXISTIMG1)s --file %(EXISTIMG1)s")  # Multiple existing files
 c.add_valid("--file %(NEWIMG1)s --file-size .00001 --nonsparse")  # Nonexistent file
 
-c = vinst.add_category("console-tests", "--nodisks")
+
+c = vinst.add_category("console-tests", "--nodisks --os-variant generic")
 c.add_valid("--pxe", grep="graphical console command: virt-viewer")  # mock default graphics+virt-viewer usage
 c.add_valid("--pxe --graphics spice,gl=on", grep="--attach")  # using virt-viewer --attach option for gl
 c.add_valid("--pxe --graphics listen=none", grep="--attach")  # using virt-viewer --attach option for listen 'none'
@@ -1192,8 +1192,8 @@ c.add_valid("--nographics --console none --location %(TREEDIR)s", grep="Director
 c.add_valid("--pxe --nographics --transient", grep="text console command: virsh")  # --transient handling
 c.add_valid("--pxe --nographics --autoconsole graphical", grep="graphical console command: virt-viewer")  # force --autoconsole graphical
 c.add_valid("--pxe --autoconsole text", grep="text console command: virsh")  # force --autoconsole text
-c.add_valid("--connect %(URI-KVM-X86)s --install fedora28 --cloud-init", grep="Password for first root login")  # make sure we print the root login password
 c.add_valid("--pxe", grep="User stopped the VM", env={"VIRTINST_TESTSUITE_HACK_DESTROY": "1"})  # fake the user destroying the VM, we should print a specific message and not reboot the VM
+c.add_valid("--connect %(URI-KVM-X86)s --install fedora28 --cloud-init", grep="Password for first root login")  # make sure we print the root login password
 c.add_invalid("--pxe --autoconsole badval", grep="Unknown autoconsole type 'badval'")
 c.add_invalid("--pxe --autoconsole text --wait -1", grep="exceeded specified time limit")  # hits a specific code path where we skip console waitpid
 

virtinst/cli.py

@@ -1825,6 +1825,7 @@ class OSVariantData(object):
         if rawstr is None or rawstr == "auto":
             # The default behavior
             self._detect = True
+            self._require = "auto"
             return
 
         if rawstr == "none":
@@ -1845,8 +1846,10 @@ class OSVariantData(object):
 
     def is_detect(self):
         return self._detect
-    def is_require(self):
+    def is_require_on(self):
-        return self._require
+        return not self.is_require_default() and bool(self._require)
+    def is_require_default(self):
+        return self._require == "auto"
     def get_name(self):
         return self._name
 

virtinst/virtinstall.py

@@ -548,8 +548,62 @@ def installer_detect_distro(guest, installer, osdata):
     except ValueError as e:
         fail(_("Error validating install location: %s") % str(e))
 
-    if not os_set and osdata.is_require():
+    msg = _(
-        fail(_("--os-variant/--osinfo OS name is required, but no value was set or detected."))
+        "--os-variant/--osinfo OS name is required, but no value was\n"
+        "set or detected.")
+    if os_set:
+        return
+    if osdata.is_require_on():
+        fail(msg)
+    if not osdata.is_require_default():
+        return
+
+    if not _needs_accurate_osinfo(guest):
+        return
+
+    fail_msg = msg + "\n\n"
+    fail_msg += _(
+        "This is now a fatal error. Specifying an OS name is required\n"
+        "for modern, performant, and secure virtual machine defaults.\n")
+
+    detect_msg = _(
+        "If you expected virt-install to detect an OS name from the\n"
+        "install media, you can set a fallback OS name with:\n"
+        "\n"
+        "  --osinfo detect=on,name=OSNAME\n")
+    possibly_detectable = bool(installer.location or installer.cdrom)
+    if possibly_detectable:
+        fail_msg += "\n" + detect_msg
+
+    fail_msg += "\n" + _(
+        "You can see a full list of possible OS name values with:\n"
+        "\n"
+        "   virt-install --osinfo list\n")
+
+    generic_linux_names = [o.name for o in virtinst.OSDB.list_os() if
+                           o.is_linux_generic()]
+    generic_linux_msg = _(
+        "If your Linux distro is not listed, try one of generic values\n"
+        "such as: {oslist}\n").format(oslist=", ".join(generic_linux_names))
+    if generic_linux_names:
+        fail_msg += "\n" + generic_linux_msg
+
+    envkey = "VIRTINSTALL_OSINFO_DISABLE_REQUIRE"
+    fail_msg += "\n" + _(
+        "If you just need to get the old behavior back, you can use:\n"
+        "\n"
+        "  --osinfo detect=on,require=off\n"
+        "\n"
+        "Or export {env_var}=1\n"
+        ).format(env_var=envkey)
+
+    fail_msg = "\n" + fail_msg
+    if envkey in os.environ:
+        log.warning(fail_msg)
+        m = _("{env_var} set. Skipping fatal error.").format(env_var=envkey)
+        log.warning(m)
+    else:
+        fail(fail_msg)
 
 
 def _build_options_guest(conn, options):