On Thu, 2022-11-24 at 10:26 +0100, Peter Zijlstra wrote: > On Wed, Nov 23, 2022 at 05:50:37PM -0800, Dan Williams wrote: > > > arch_add_memory() does not add memory to the page allocator. For > > example, memremap_pages() uses arch_add_memory() and explicitly does not > > release the memory to the page allocator. This check belongs in > > add_memory_resource() to prevent new memory that violates TDX from being > > onlined. Hopefully there is also an option to disable TDX from the > > kernel boot command line to recover memory-hotplug without needing to > > boot into the BIOS to toggle TDX. > > So I've been pushing for all this to either require: tdx=force on the > cmdline to boot-time enable, or delay all the memory allocation to the > first KVM/TDX instance being created. > > That is, by default, none of this crud should ever trigger and consume > memory if you're not using TDX (most of us really). > > (every machine I have loads kvm.ko unconditionally -- even if I never > user KVM, so kvm.ko load time is not a valid point in time to do TDX > enablement). > Thanks for input. I am fine with 'tdx=force'. Although, I'd like to point out KVM will have a module parameter 'enable_tdx'. Hi Dave, Sean, do you have any comments?
