On 2/16/23 10:12, Kirill A. Shutemov wrote: > On Thu, Feb 16, 2023 at 09:50:32AM -0800, Dave Hansen wrote: >> On 2/13/23 15:48, Kirill A. Shutemov wrote: >>> The patch brings basic enabling of kexec in TDX guests. >>> >>> By "basic enabling" I mean, kexec in the guests with a single CPU. >>> TDX guests use ACPI MADT MPWK to bring up secondary CPUs. The mechanism >>> doesn't allow to put a CPU back offline if it has woken up. >>> >>> We are looking into this, but it might take time. >> This is simple enough. But, nobody will _actually_ use this code as-is, >> right? What's the point of applying it now? > Why nobody? Single CPU VMs are not that uncommon. Here's one data point: the only "General Purpose" ones I see AWS offering are Haswell era: https://aws.amazon.com/ec2/instance-types/ That _might_ be because of concerns about SMT side-channel exposure on anything newer. So, we can argue about what "uncommon" means. But, a minority of folks care about 1-cpu VMs. Also, a separate minority of folks care about kexec(). I'm worried that the overlap between the two will be an *OVERWHELMING* minority of folks. In other words, so few people will use this code that it'll just bitrot. I'm looking for compelling arguments why mainline should carry this. _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
