cd9e6da804
Unwind the RIP advancement done by svm_queue_exception() when injecting
an INT3 ultimately "fails" due to the CPU encountering a VM-Exit while
vectoring the injected event, even if the exception reported by the CPU
isn't the same event that was injected. If vectoring INT3 encounters an
exception, e.g. #NP, and vectoring the #NP encounters an intercepted
exception, e.g. #PF when KVM is using shadow paging, then the #NP will
be reported as the event that was in-progress.
Note, this is still imperfect, as it will get a false positive if the
INT3 is cleanly injected, no VM-Exit occurs before the IRET from the INT3
handler in the guest, the instruction following the INT3 generates an
exception (directly or indirectly), _and_ vectoring that exception
encounters an exception that is intercepted by KVM. The false positives
could theoretically be solved by further analyzing the vectoring event,
e.g. by comparing the error code against the expected error code were an
exception to occur when vectoring the original injected exception, but
SVM without NRIPS is a complete disaster, trying to make it 100% correct
is a waste of time.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Fixes: 66b7138f9136 ("KVM: SVM: Emulate nRIP feature when reinjecting INT3")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <450133cf0a026cb9825a2ff55d02cb136a1cb111.1651440202.git.maciej.szmigiero@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.