linux/arch/s390/kvm
David Hildenbrand 4d4cee96fb KVM: s390: vsie: Fix delivery of addressing exceptions
Whenever we get an -EFAULT, we failed to read in guest 2 physical
address space. Such addressing exceptions are reported via a program
intercept to the nested hypervisor.

We faked the intercept, we have to return to guest 2. Instead, right
now we would be returning -EFAULT from the intercept handler, eventually
crashing the VM.
the correct thing to do is to return 1 as rc == 1 is the internal
representation of "we have to go back into g2".

Addressing exceptions can only happen if the g2->g3 page tables
reference invalid g2 addresses (say, either a table or the final page is
not accessible - so something that basically never happens in sane
environments.

Identified by manual code inspection.

Fixes: a3508fbe9d ("KVM: s390: vsie: initial support for nested virtualization")
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200403153050.20569-3-david@redhat.com
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
[borntraeger@de.ibm.com: fix patch description]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-04-07 13:12:34 +02:00
..
diag.c KVM: s390: protvirt: Report CPU state to Ultravisor 2020-02-27 19:47:12 +01:00
gaccess.c KVM: s390: Use fallthrough; 2020-03-23 18:30:07 +01:00
gaccess.h KVM: s390: Remove redundant license text 2017-12-06 09:18:42 +01:00
guestdbg.c KVM: s390: introduce defines for control registers 2018-05-17 09:02:27 +02:00
intercept.c KVM: s390: Features and Enhancements for 5.7 part1 2020-03-16 18:19:34 +01:00
interrupt.c KVM: s390: Use fallthrough; 2020-03-23 18:30:07 +01:00
irq.h KVM: s390: Remove redundant license text 2017-12-06 09:18:42 +01:00
Kconfig * ARM: support for SVE and Pointer Authentication in guests, PMU improvements 2019-05-17 10:33:30 -07:00
kvm-s390.c ARM: 2020-04-02 15:13:15 -07:00
kvm-s390.h KVM: s390: protvirt: Report CPU state to Ultravisor 2020-02-27 19:47:12 +01:00
Makefile KVM: s390: protvirt: Add initial vm and cpu lifecycle handling 2020-02-27 19:47:11 +01:00
priv.c KVM: s390: protvirt: STSI handling 2020-02-27 19:47:12 +01:00
pv.c KVM: s390: protvirt: Report CPU state to Ultravisor 2020-02-27 19:47:12 +01:00
sigp.c KVM: s390: introduce and use kvm_s390_test_cpuflags() 2018-01-24 17:46:42 +01:00
trace-s390.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vsie.c KVM: s390: vsie: Fix delivery of addressing exceptions 2020-04-07 13:12:34 +02:00