BugLink: https://bugs.launchpad.net/bugs/1864775

commit 13c5183a upstream.

This fixes a Spectre-v1/L1TF vulnerability in the get_gp_pmc() and
get_fixed_pmc() functions.
They both contain index computations based on the (attacker-controlled)
MSR number.

Fixes: 25462f7f ("KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch")
Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>