[PATCH v3 0/7] x86: KVM: svm: get rid of hardcoded instructions lengths

From: Vitaly Kuznetsov
Date: Thu Aug 08 2019 - 13:30:58 EST


Changes since v2 [Sean Christopherson]:
- Add Reviewed-by tags:
- PATCH2 replaced with the suggested "x86: kvm: svm: propagate errors from
skip_emulated_instruction()" approach.
- PATCH5 split into three separating vmrun_interception() from others and
implementing the suggested solution.

Original description:

Jim rightfully complains that hardcoding instuctions lengths is not always
correct: additional (redundant) prefixes can be used. Luckily, the ugliness
is mostly harmless: modern AMD CPUs support NRIP_SAVE feature but I'd like
to clean things up and sacrifice speed in favor of correctness.

Vitaly Kuznetsov (7):
x86: KVM: svm: don't pretend to advance RIP in case
wrmsr_interception() results in #GP
x86: kvm: svm: propagate errors from skip_emulated_instruction()
x86: KVM: clear interrupt shadow on EMULTYPE_SKIP
x86: KVM: add xsetbv to the emulator
x86: KVM: svm: remove hardcoded instruction length from intercepts
x86: KVM: svm: eliminate weird goto from vmrun_interception()
x86: KVM: svm: eliminate hardcoded RIP advancement from
vmrun_interception()

arch/x86/include/asm/kvm_emulate.h | 3 +-
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/emulate.c | 23 ++++++-
arch/x86/kvm/svm.c | 98 +++++++++++++-----------------
arch/x86/kvm/vmx/vmx.c | 8 ++-
arch/x86/kvm/x86.c | 13 +++-
6 files changed, 83 insertions(+), 64 deletions(-)

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2.20.1