e27e46d5e5
commit 901d3765fa804ce42812f1d5b1f3de2dfbb26723 upstream.
Commit 7e2175ebd695 ("KVM: x86: Fix recording of guest steal time
/ preempted status", 2021-11-11) open coded the previous call to
kvm_map_gfn, but in doing so it dropped the comparison between the cached
guest physical address and the one in the MSR. This cause an incorrect
cache hit if the guest modifies the steal time address while the memslots
remain the same. This can happen with kexec, in which case the steal
time data is written at the address used by the old kernel instead of
the old one.
While at it, rename the variable from gfn to gpa since it is a plain
physical address and not a right-shifted one.
Reported-by: Dave Young <ruyang@redhat.com>
Reported-by: Xiaoying Yan <yiyan@redhat.com>
Analyzed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: stable@vger.kernel.org
Fixes: 7e2175ebd695 ("KVM: x86: Fix recording of guest steal time / preempted status")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.