From: David Hildenbrand <david@redhat.com>
To: kvm@vger.kernel.org
Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
Vasily Gorbik <gor@linux.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Cornelia Huck <cohuck@redhat.com>,
Janosch Frank <frankja@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
David Hildenbrand <david@redhat.com>,
stable@vger.kernel.org
Subject: [PATCH v1 2/5] KVM: s390: vsie: Fix delivery of addressing exceptions
Date: Thu, 2 Apr 2020 20:48:16 +0200 [thread overview]
Message-ID: <20200402184819.34215-3-david@redhat.com> (raw)
In-Reply-To: <20200402184819.34215-1-david@redhat.com>
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.
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>
---
arch/s390/kvm/vsie.c | 1 +
1 file changed, 1 insertion(+)
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;
}
--
2.25.1
next prev parent reply other threads:[~2020-04-02 18:48 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-02 18:48 [PATCH v1 0/5] KVM: s390: vsie: fixes and cleanups David Hildenbrand
2020-04-02 18:48 ` [PATCH v1 1/5] KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checks David Hildenbrand
2020-04-03 12:07 ` David Hildenbrand
2020-04-03 13:41 ` Janosch Frank
2020-04-02 18:48 ` David Hildenbrand [this message]
2020-04-06 13:17 ` [PATCH v1 2/5] KVM: s390: vsie: Fix delivery of addressing exceptions Christian Borntraeger
2020-04-06 13:22 ` David Hildenbrand
2020-04-06 13:24 ` Christian Borntraeger
2020-04-02 18:48 ` [PATCH v1 3/5] KVM: s390: vsie: Fix possible race when shadowing region 3 tables David Hildenbrand
2020-04-06 13:47 ` Christian Borntraeger
2020-04-02 18:48 ` [PATCH v1 4/5] KVM: s390: vsie: Move conditional reschedule David Hildenbrand
2020-04-02 18:48 ` [PATCH v1 5/5] KVM: s390: vsie: gmap_table_walk() simplifications David Hildenbrand
2020-04-03 13:03 ` Janosch Frank
2020-04-03 13:09 ` David Hildenbrand
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