Almost most of the devices were effected by these Meltdown and Spectre flaws including the Apple devices.Both the "Spectre and Meltdown" flaws affect the performance of CPU feature called Speculative Execution which is responsible for improving speed and operate multiple operations.
Intel had announced the patches for Meltdown and Spectre hardware flaws however the exact number of devices affected remains unknown. This is to minimize the performance impact of the original Meltdown and Spectre patches on Intel devices. Then a third category would be users with such an older chip and Windows 7 or 8, according to Microsoft, will notice a further reduction in the performance of their PC.
An employee of Google's Project Zero was the first to discover the two vulnerabilities, and the company justified breaking the embargo, saying: "We are posting before an originally co-ordinated disclosure date of 9 January 2018 because of existing public reports and growing speculation in the press and security research community about the issue, which raises the risk of exploitation".
Mark Papermaster, AMD's Senior Vice President and Chief Technology Officer, wrote "while we believe that AMD's processor architectures make it difficult to exploit Variant 2, we continue to work closely with the industry on this threat". To get your affected PC back to a bootable state, you will have to visit Microsoft's support site for fixes.
So, nothing has happened yet (at least so we are told). The kernel memory is not supposed to be accessible to applications although the meltdown vulnerability could allow access by outside malicious actors.