tree 2aec852e2d10c710c79d5a6b50b680d05aeff460
parent 59c5f46fbe01a00eedf54a23789634438bb80603
author Christian Borntraeger <borntraeger@de.ibm.com> 1307362478 +0200
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1307362496 +0200

[S390] kvm-s390: Fix host crash on misbehaving guests

commit 9ff4cfb3fcfd48b49fdd9be7381b3be340853aa4 ([S390] kvm-390: Let
kernel exit SIE instruction on work) fixed a problem of commit
commit cd3b70f5d4d82f85d1e1d6e822f38ae098cf7c72 ([S390] virtualization
aware cpu measurement) but uncovered another one.

If a kvm guest accesses guest real memory that doesnt exist, the
page fault handler calls the sie hook, which then rewrites
the return psw from sie_inst to either sie_exit or sie_reenter.
On return, the page fault handler will then detect the wrong access
as a kernel fault causing a kernel oops in sie_reenter or sie_exit.

We have to add these two addresses to the exception  table to allow
graceful exits.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>