Making Testcases aware that they are running in a virtualization environment

Hi LTP users and developers,
This is a discussion which needs the comments and thoughts from everyone. Currently we see a major focus on operating system virtualization. There are many hypervisors, KVM being one of the latest ones. LTP has been executed on a variety of OSes on different hardware plateforms. However the envronment for an application(or say LTP itslef) running in the host OS vs in the guest OS might not be same in all respects. Though the goal of virtualization is to make the two environments almost exact, but for some tools like LTP this may not be 100% possible. For example, If I am calculating cpu time under a guest OS I can not normalize it to the total cpu time in the system as it all depends on the guest scheduling.(different hypervisors have their own mechanism). Other example can be cpu consolidation testcases which can not be executed under a kvm test-bed. I think group scheduling may be the next example. Similarly there can be more testcases or scenarios which need them be aware that they are running under a virtualization environment and should be able to handle the test execution accordingly. Thus in some cases the test should either run with proper care or should not execute or should break instead of failing due to improper configuration.

The outcome of this discussion should be able to provide:

1. What are the thoughts of the community on this concern of LTP.

2. To collect the existing testcases in LTP which need this modification.

3. Taking care that all the future cases which are virtualization sensitive should be able to handle it well.

4. In what all ways we can come to know which hypervisor is the guest running on. For KVM we can do something like
if [ cat /proc/cpuinfo | grep -w "model name" | cut -f3 -d " " | head -n 1 == "QEMU" ]; then echo "KVM Guest"; else echo "Non KVM Guest"; fi

5. Test developers can send quick patches if the testcases developed by them need to have this feature.

6. Modify the LTP How-To to include the virtualization awareness warning for testcases.

Please provide your valuable comments and the name of tescases which you know do need such a modification. If people do not have time we may try to modify them or put at least in the TODO on the wiki.

Hi Sudhir,

Thanks for your suggestion. Let us suppose

Quoted 45 lines · Sudhir Kumar

Hi LTP users and developers,
This is a discussion which needs the comments and thoughts from everyone. Currently we see a major focus on operating system virtualization. There are many hypervisors, KVM being one of the latest ones. LTP has been executed on a variety of OSes on different hardware plateforms. However the envronment for an application(or say LTP itslef) running in the host OS vs in the guest OS might not be same in all respects. Though the goal of virtualization is to make the two environments almost exact, but for some tools like LTP this may not be 100% possible. For example, If I am calculating cpu time under a guest OS I can not normalize it to the total cpu time in the system as it all depends on the guest scheduling.(different hypervisors have their own mechanism). Other example can be cpu consolidation testcases which can not be executed under a kvm test-bed. I think group scheduling may be the next example. Similarly there can be more testcases or scenarios which need them be aware that they are running under a virtualization environment and should be able to handle the test execution accordingly. Thus in some cases the test should either run with proper care or should not execute or should break instead of failing due to improper configuration.

The outcome of this discussion should be able to provide:

1. What are the thoughts of the community on this concern of LTP.

2. To collect the existing testcases in LTP which need this modification.

3. Taking care that all the future cases which are virtualization sensitive should be able to handle it well.

4. In what all ways we can come to know which hypervisor is the guest running on. For KVM we can do something like
if [ cat /proc/cpuinfo | grep -w "model name" | cut -f3 -d " " | head -n 1 == "QEMU" ]; then echo "KVM Guest"; else echo "Non KVM Guest"; fi

5. Test developers can send quick patches if the testcases developed by them need to have this feature.

6. Modify the LTP How-To to include the virtualization awareness warning for testcases.

Please provide your valuable comments and the name of tescases which you know do need such a modification. If people do not have time we may try to modify them or put at least in the TODO on the wiki.

Quoted 1 line