linux-kernel - [PATCH v2 0/9] KVM: my debug patch queue

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Message-Id: <20210401135451.1004564-1-mlevitsk@redhat.com>
Date:   Thu,  1 Apr 2021 16:54:42 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        Ingo Molnar <mingo@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Sean Christopherson <seanjc@...gle.com>,
        Marc Zyngier <maz@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        linux-kernel@...r.kernel.org (open list),
        Julien Thierry <julien.thierry.kdev@...il.com>,
        Stefano Garzarella <sgarzare@...hat.com>,
        Borislav Petkov <bp@...en8.de>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Jonathan Corbet <corbet@....net>, Jessica Yu <jeyu@...nel.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        Jan Kiszka <jan.kiszka@...mens.com>,
        Will Deacon <will@...nel.org>,
        kvmarm@...ts.cs.columbia.edu (open list:KERNEL VIRTUAL MACHINE FOR
        ARM64 (KVM/arm64)), Paolo Bonzini <pbonzini@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Joerg Roedel <joro@...tes.org>,
        Claudio Imbrenda <imbrenda@...ux.ibm.com>,
        Jim Mattson <jmattson@...gle.com>,
        Cornelia Huck <cohuck@...hat.com>,
        David Hildenbrand <david@...hat.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Janosch Frank <frankja@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ibm.com>,
        linux-s390@...r.kernel.org (open list:S390),
        Heiko Carstens <hca@...ux.ibm.com>,
        Kieran Bingham <kbingham@...nel.org>,
        linux-doc@...r.kernel.org (open list:DOCUMENTATION),
        linux-arm-kernel@...ts.infradead.org (moderated list:KERNEL VIRTUAL
        MACHINE FOR ARM64 (KVM/arm64)), James Morse <james.morse@....com>
Subject: [PATCH v2 0/9] KVM: my debug patch queue

Hi!

I would like to publish two debug features which were needed for other stuff
I work on.

One is the reworked lx-symbols script which now actually works on at least
gdb 9.1 (gdb 9.2 was reported to fail to load the debug symbols from the kernel
for some reason, not related to this patch) and upstream qemu.

The other feature is the ability to trap all guest exceptions (on SVM for now)
and see them in kvmtrace prior to potential merge to double/triple fault.

This can be very useful and I already had to manually patch KVM a few
times for this.
I will, once time permits, implement this feature on Intel as well.

V2:

 * Some more refactoring and workarounds for lx-symbols script

 * added KVM_GUESTDBG_BLOCKEVENTS flag to enable 'block interrupts on
   single step' together with KVM_CAP_SET_GUEST_DEBUG2 capability
   to indicate which guest debug flags are supported.

   This is a replacement for unconditional block of interrupts on single
   step that was done in previous version of this patch set.
   Patches to qemu to use that feature will be sent soon.

 * Reworked the the 'intercept all exceptions for debug' feature according
   to the review feedback:

   - renamed the parameter that enables the feature and
     moved it to common kvm module.
     (only SVM part is currently implemented though)

   - disable the feature for SEV guests as was suggested during the review
   - made the vmexit table const again, as was suggested in the review as well.

Best regards,
	Maxim Levitsky

Maxim Levitsky (9):
  scripts/gdb: rework lx-symbols gdb script
  KVM: introduce KVM_CAP_SET_GUEST_DEBUG2
  KVM: x86: implement KVM_CAP_SET_GUEST_DEBUG2
  KVM: aarch64: implement KVM_CAP_SET_GUEST_DEBUG2
  KVM: s390x: implement KVM_CAP_SET_GUEST_DEBUG2
  KVM: x86: implement KVM_GUESTDBG_BLOCKEVENTS
  KVM: SVM: split svm_handle_invalid_exit
  KVM: x86: add force_intercept_exceptions_mask
  KVM: SVM: implement force_intercept_exceptions_mask

 Documentation/virt/kvm/api.rst    |   4 +
 arch/arm64/include/asm/kvm_host.h |   4 +
 arch/arm64/kvm/arm.c              |   2 +
 arch/arm64/kvm/guest.c            |   5 -
 arch/s390/include/asm/kvm_host.h  |   4 +
 arch/s390/kvm/kvm-s390.c          |   3 +
 arch/x86/include/asm/kvm_host.h   |  12 ++
 arch/x86/include/uapi/asm/kvm.h   |   1 +
 arch/x86/kvm/svm/svm.c            |  87 +++++++++++--
 arch/x86/kvm/svm/svm.h            |   6 +-
 arch/x86/kvm/x86.c                |  14 ++-
 arch/x86/kvm/x86.h                |   2 +
 include/uapi/linux/kvm.h          |   1 +
 kernel/module.c                   |   8 +-
 scripts/gdb/linux/symbols.py      | 203 ++++++++++++++++++++----------
 15 files changed, 272 insertions(+), 84 deletions(-)

-- 
2.26.2