KVM: nVMX: Truncate base/index GPR value on address calc in !64-bit

KVM: nVMX: Truncate base/index GPR value on address calc in !64-bit

commit 82277eeed65eed6c6ee5b8f97bd978763eab148f upstream.

Drop bits 63:32 of the base and/or index GPRs when calculating the
effective address of a VMX instruction memory operand.  Outside of 64-bit
mode, memory encodings are strictly limited to E*X and below.

Fixes: 064aea774768 ("KVM: nVMX: Decoding memory operands of VMX instructions")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422022128.3464144-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>