On Thu, Aug 29, 2019 at 08:23:18AM +0000, Jan Dakinevich wrote:
> inject_emulated_exception() returns true if and only if nested page
> fault happens. However, page fault can come from guest page tables
> walk, either nested or not nested. In both cases we should stop an
> attempt to read under RIP and give guest to step over its own page
> fault handler.
>
> Fixes: 6ea6e84 ("KVM: x86: inject exceptions produced by x86_decode_insn")
Commit ids should be at least 12 chars, the full tag should be
Fixes: 6ea6e84309ca ("KVM: x86: inject exceptions produced by x86_decode_insn")
You can force this in your git config, e.g.
git config --global core.abbrev 12
Both patches in this series should probably have
Cc: <stable@xxxxxxxxxxxxxxx>
Reviewed-and-tested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Cc: Denis Lunev <den@xxxxxxxxxxxxx>
> Cc: Roman Kagan <rkagan@xxxxxxxxxxxxx>
> Cc: Denis Plotnikov <dplotnikov@xxxxxxxxxxxxx>
> Signed-off-by: Jan Dakinevich <jan.dakinevich@xxxxxxxxxxxxx>
> ---
> arch/x86/kvm/x86.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index b4cfd78..6bf7b55 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6537,8 +6537,13 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
> if (reexecute_instruction(vcpu, cr2, write_fault_to_spt,
> emulation_type))
> return EMULATE_DONE;
> - if (ctxt->have_exception && inject_emulated_exception(vcpu))
> + if (ctxt->have_exception) {
> + WARN_ON_ONCE(ctxt->exception.vector == UD_VECTOR);
> + WARN_ON_ONCE(exception_type(ctxt->exception.vector)
> + == EXCPT_TRAP);
> + inject_emulated_exception(vcpu);
> return EMULATE_DONE;
> + }
> if (emulation_type & EMULTYPE_SKIP)
> return EMULATE_FAIL;
> return handle_emulation_failure(vcpu, emulation_type);
> --
> 2.1.4
>
