[vfio-users] Spectre, meltdown what's the performance implication for vga-passthrough gaming setups?

[Bronek Kozicki]

On Sun, 7 Jan 2018, at 12:00 PM, Patrick O'Callaghan wrote:
> On Sun, 2018-01-07 at 11:28 +0000, Ivan Volosyuk wrote:
> > From what I heard virtualization setups suffer the most from the vulnerabilities. After virtualized windows is patched as well as host linux what is the expected slowdown for gaming? I have pretty much zero understanding how much syscall/interrupt heavy qemu/kvm with vfio. 
> > Is it time to urgently switch to AMD CPU?
> 
> I have patched Linux host and patched Windows guest and haven't noticed
> anything so far. Games are unlikely to be severely slowed down as much
> of the work is done by the GPU with relatively few system calls.

I patched my host (kernel 4.14.12) , and I also have Windows 10 which self-updated  to https://support.microsoft.com/en-gb/help/4056892/ . While I can see that the PTI has been activated in the host:

% dmesg | grep isolation
[    0.000000] Kernel/User page tables isolation: enabled

... but I am not so sure about the guest systems. Anyway, with the patch active in the host the guest machines are just fine for gaming.


B.