* Stefan Berger (stef...@linux.vnet.ibm.com) wrote: > On 03/28/2018 11:48 AM, Marc-André Lureau wrote: > > Hi > > > > On Fri, Mar 16, 2018 at 10:46 PM, Stefan Berger > > <stef...@linux.vnet.ibm.com> wrote: > > > Extend the docs related to TPM with specs related to VM save and > > > restore and a troubleshooting guide for TPM migration. > > > > > Thanks a lot for writing this! some questions below > > > > > Signed-off-by: Stefan Berger <stef...@linux.vnet.ibm.com> > > > --- > > > docs/specs/tpm.txt | 106 > > > +++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 106 insertions(+) > > > > > > diff --git a/docs/specs/tpm.txt b/docs/specs/tpm.txt > > > index d1d7157..c230c4c 100644 > > > --- a/docs/specs/tpm.txt > > > +++ b/docs/specs/tpm.txt > > > @@ -200,3 +200,109 @@ crw-------. 1 root root 10, 224 Jul 11 10:11 > > > /dev/tpm0 > > > PCR-00: 35 4E 3B CE 23 9F 38 59 ... > > > ... > > > PCR-23: 00 00 00 00 00 00 00 00 ... > > > + > > > + > > > +=== Migration with the TPM emulator === > > > + > > > +The TPM emulator supports the following types of virtual machine > > > migration: > > > + > > > +- VM save / restore (migration into a file) > > > +- Network migration > > > +- Snapshotting (migration into storage like QoW2 or QED) > > > + > > > +The following command sequences can be used to test VM save / restore. > > > + > > > + > > > +In a 1st terminal start an instance of a swtpm using the following > > > command: > > > + > > > +mkdir /tmp/mytpm1 > > > +swtpm socket --tpmstate dir=/tmp/mytpm1 \ > > > + --ctrl type=unixio,path=/tmp/mytpm1/swtpm-sock \ > > > + --log level=20 --tpm2 > > > + > > > +In a 2nd terminal start the VM: > > > + > > > +qemu-system-x86_64 -display sdl -enable-kvm \ > > > + -m 1024 -boot d -bios bios-256k.bin -boot menu=on \ > > > + -chardev socket,id=chrtpm,path=/tmp/mytpm1/swtpm-sock \ > > > + -tpmdev emulator,id=tpm0,chardev=chrtpm \ > > > + -device tpm-tis,tpmdev=tpm0 \ > > > + -monitor stdio \ > > > + test.img > > > + > > > +Verify that the attached TPM is working as expected using applications > > > inside > > > +the VM. > > > + > > > +To store the state of the VM use the following command in the QEMU > > > monitor in > > > +the 2nd terminal: > > > + > > > +(qemu) migrate "exec:cat > testvm.bin" > > > +(qemu) quit > > > + > > > +At this point a file called 'testvm.bin' should exists and the swtpm and > > > QEMU > > > +processes should have ended. > > When is swtpm ending, when qemu leaves? Hopefully you can do several > > migrate commands. > > Yes, QEMU does not send it the signal to shut down. We can fall back to the > source if the destination fails. > > > > > > + > > > +To test 'VM restore' you have to start the swtpm with the same parameters > > > +as before. If previously a TPM 2 [--tpm2] was saved, --tpm2 must now be > > > +passed again on the command line. > > > + > > > +In the 1st terminal restart the swtpm with the same command line as > > > before: > > > + > > > +swtpm socket --tpmstate dir=/tmp/mytpm1 \ > > > + --ctrl type=unixio,path=/tmp/mytpm1/swtpm-sock \ > > > + --log level=20 --tpm2 > > Does that mean the tpmstate directory content must be the same and > > thus migrated as well? Can in be empty in the destination? If not, > > what should be done to initialize it? Could it be empty instead? > > QEMU migrates the state of the TPM with the CMD_GET_STATEBLOB to retrieve > the state blobs and CMD_SET_STATEBLOB to set them on the destination. The > destination only needs to have the TPM running but the directory must have > been created (--tpmstate dir=...). > > One can try this with localhost migration over the network as well, but I > didn't want to show this more complicated scenario in the doc: > > destination QEMU: > sudo ./x86_64-softmmu/qemu-system-x86_64 -vnc :11 -enable-kvm -m 1024 -smp 8 > -boot d -L /usr/share/seabios -bios bios-256k.bin -boot menu=on -chardev > socket,id=chrtpm,path=/tmp/mytpm2/ctrl.sock -tpmdev > emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 -monitor stdio > -chardev file,id=pts2,path=/tmp/seabios.log -device isa-serial,chardev=pts2 > /var/lib/libvirt/images/FC27 -incoming "exec:nc -l 127.0.0.1 12345" > > source QEMU: > sudo ./x86_64-softmmu/qemu-system-x86_64 -vnc :10 -enable-kvm -m 1024 -smp 8 > -boot d -L /usr/share/seabios -bios bios-256k.bin -boot menu=on -chardev > socket,id=chrtpm,path=/tmp/mytpm1/ctrl.sock -tpmdev > emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 -monitor stdio > -chardev file,id=pts2,path=/tmp/seabios.log -device isa-serial,chardev=pts2 > /var/lib/libvirt/images/FC27 > > (qemu) migrate "exec:nc 127.0.0.1 12345"
Migration has a tcp form that's a bit easier; -incoming tcp:127.0.0.1:12345 migrate tcp:127.0.0.1:12345 Dave > Just tested again. > > Stefan > > > > > + > > > +In the 2nd terminal restore the state of the VM using the additonal > > > +'-incoming' option. > > > + > > > +qemu-system-x86_64 -display sdl -enable-kvm \ > > > + -m 1024 -boot d -bios bios-256k.bin -boot menu=on \ > > > + -chardev socket,id=chrtpm,path=/tmp/mytpm1/swtpm-sock \ > > > + -tpmdev emulator,id=tpm0,chardev=chrtpm \ > > > + -device tpm-tis,tpmdev=tpm0 \ > > > + -incoming "exec:cat < testvm.bin" \ > > > + test.img > > > + > > > + > > > +Troubleshooting migration: > > > + > > > +There are several reasons why migration may fail. In case of problems, > > > +please ensure that the command lines adhere to the following rules and, > > > +if possible, that identical versions of QEMU and swtpm are used at all > > > +times. > > > + > > > +VM save and restore: > > > + - QEMU command line parameters should be identical apart from the > > > + '-incoming' option on VM restore > > > + - swtpm command line parameters should be identical > > > + > > > +VM migration to 'localhost': > > > + - QEMU command line parameters should be identical apart from the > > > + '-incoming' option on the destination side > > > + - swtpm command line parameters should point to two different > > > + directories on the source and destination swtpm (--tpmstate dir=...) > > > + (especially if different versions of libtpms were to be used on the > > > + same machine). > > > + > > > +VM migration across the network: > > > + - QEMU command line parameters should be identical apart from the > > > + '-incoming' option on the destination side > > > + - swtpm command line parameters should be identical > > > + > > > +VM Snapshotting: > > > + - QEMU command line parameters should be identical > > > + - swtpm command line parameters should be identical > > > + > > > + > > > +Besides that, migration failure reasons on the swtpm level may include > > > +the following: > > > + > > > + - the versions of the swtpm on the source and destination sides are > > > + incompatible > > > + - downgrading of TPM state may not be supported > > > + - the source and destination libtpms were compiled with different > > > + compile-time options and the destination side refuses to accept the > > > + state > > > + - different migration keys are used on the source and destination side > > > + and the destination side cannot decrypt the migrated state > > > + (swtpm ... --migration-key ... ) > > > -- > > > 2.5.5 > > > > > > > > > > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
