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From: Beata Michalska <beata.michalska@linaro.org>
To: qemu-devel@nongnu.org
Cc: qemu-arm@nongnu.org, kvmarm@lists.cs.columbia.edu, pbonzini@redhat.com
Subject: [PATCH v2 0/2] target/arm: kvm: Support for KVM DABT without valid ISS
Date: Wed, 29 Jan 2020 20:24:39 +0000
Message-ID: <20200129202441.12745-1-beata.michalska@linaro.org> (raw)

Some of the ARMv7 & ARMv8 load/store instructions might trigger a data abort
exception with no valid ISS info to be decoded. The lack of decode info
makes it at least tricky to emulate the instruction which is one of the
(many) reasons why KVM will not even try to do so.

So far, if a guest made an attempt to access memory outside the memory slot,
KVM reported vague ENOSYS. As a result QEMU exited with no useful information
being provided or even a clue on what has just happened.

ARM KVM introduced support for notifying guest of an attempt to execute
an instruction that resulted in dabt with no valid ISS decoding info.
This still leaves QEMU to handle the case, but at least now, it can enable
further debugging of the encountered issue by being more verbose
in a (hopefully) useful way.

- Improving/re-phrasing messaging
- Dropping messing around with forced sync (@see [PATCH v2 1/2])
  and PC alignment

Beata Michalska (2):
  target/arm: kvm: Inject events at the last stage of sync
  target/arm: kvm: Handle DABT with no valid ISS

 target/arm/cpu.h     |  2 ++
 target/arm/kvm.c     | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 target/arm/kvm32.c   | 23 +++++++------
 target/arm/kvm64.c   | 23 +++++++------
 target/arm/kvm_arm.h | 19 +++++++++++
 5 files changed, 143 insertions(+), 20 deletions(-)


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Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-29 20:24 Beata Michalska [this message]
2020-01-29 20:24 ` [PATCH v2 1/2] target/arm: kvm: Inject events at the last stage of sync Beata Michalska
2020-02-04 10:34   ` Andrew Jones
2020-02-06 21:41     ` Beata Michalska
2020-02-07  7:41       ` Andrew Jones
2020-01-29 20:24 ` [PATCH v2 2/2] target/arm: kvm: Handle DABT with no valid ISS Beata Michalska
2020-02-05 16:57   ` Andrew Jones
2020-02-06 21:48     ` Beata Michalska
2020-02-07  8:19       ` Andrew Jones
2020-02-11 23:10         ` Beata Michalska

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