Hi
There is a long-standing problem whereby running Intel PT on host and guest in Host/Guest mode, causes VM-Entry failure.
The motivation for this patch set is to provide a fix for stable kernels prior to the advent of the "Mediated Passthrough vPMU" patch set:
https://lore.kernel.org/kvm/20240801045907.4010984-1-mizhang@google.com/
which would render a large part of the fix unnecessary but likely not be suitable for backport to stable due to its size and complexity.
Ideally, this patch set would be applied before "Mediated Passthrough vPMU"
Note that the fix does not conflict with "Mediated Passthrough vPMU", it is just that "Mediated Passthrough vPMU" will make the code to stop and restart Intel PT unnecessary.
Adrian Hunter (3): KVM: x86: Fix Intel PT IA32_RTIT_CTL MSR validation KVM: x86: Fix Intel PT Host/Guest mode when host tracing also KVM: selftests: Add guest Intel PT test
arch/x86/events/intel/pt.c | 131 ++++++- arch/x86/events/intel/pt.h | 10 + arch/x86/include/asm/intel_pt.h | 4 + arch/x86/kvm/vmx/vmx.c | 26 +- arch/x86/kvm/vmx/vmx.h | 1 - tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/include/x86_64/processor.h | 1 + tools/testing/selftests/kvm/x86_64/intel_pt.c | 381 +++++++++++++++++++++ 8 files changed, 532 insertions(+), 23 deletions(-) create mode 100644 tools/testing/selftests/kvm/x86_64/intel_pt.c
base-commit: d45aab436cf06544abeeffc607110f559a3af3b4
Regards Adrian