02cba24f98
commit 342993f96ab24d5864ab1216f46c0b199c2baf8e upstream.
After commit 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest
mode") Hyper-V guests on KVM stopped booting with:
kvm_nested_vmexit: rip fffff802987d6169 reason EPT_VIOLATION info1 181
info2 0 int_info 0 int_info_err 0
kvm_page_fault: address febd0000 error_code 181
kvm_emulate_insn: 0:fffff802987d6169: f3 a5
kvm_emulate_insn: 0:fffff802987d6169: f3 a5 FAIL
kvm_inj_exception: #UD (0x0)
"f3 a5" is a "rep movsw" instruction, which should not be intercepted
at all. Commit c44b4c6ab80e ("KVM: emulate: clean up initializations in
init_decode_cache") reduced the number of fields cleared by
init_decode_cache() claiming that they are being cleared elsewhere,
'intercept', however, is left uncleared if the instruction does not have
any of the "slow path" flags (NotImpl, Stack, Op3264, Sse, Mmx, CheckPerm,
NearBranch, No16 and of course Intercept itself).
Fixes: c44b4c6ab80e ("KVM: emulate: clean up initializations in init_decode_cache")
Fixes: 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest mode")
Cc: stable@vger.kernel.org
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.