diff options
| author |   David Hildenbrand <david@redhat.com> | 2020-04-03 17:30:47 +0200 |
|---|---|---|
| committer |   Christian Borntraeger <borntraeger@de.ibm.com> | 2020-04-07 13:12:34 +0200 |
| commit | 4d4cee96fb7a3cc53702a9be8299bf525be4ee98 (patch) | |
| tree | 0b08caaf0900541290acc03a4655ecbb84065d90 /arch/s390/kvm | |
| parent | KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checks (diff) | |
| download | linux-dev-4d4cee96fb7a3cc53702a9be8299bf525be4ee98.tar.xz linux-dev-4d4cee96fb7a3cc53702a9be8299bf525be4ee98.zip | |
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: a3508fbe9dc6 ("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>
Diffstat (limited to 'arch/s390/kvm')
| -rw-r--r-- | arch/s390/kvm/vsie.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 076090f9e666..4f6c22d72072 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -1202,6 +1202,7 @@ static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) scb_s->iprcc = PGM_ADDRESSING; scb_s->pgmilc = 4; scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); + rc = 1; } return rc; } |