moby
HPET: 64-bit main counter
What would it take to implement 64-bit main counter - https://github.com/moby/hyperkit/blob/8975f80ae46ef315e600552328ba63af09b742f7/src/lib/vmm/io/vhpet.c#L96?
Could anyone please weigh in on it? Would you be interested in a pull request to enhance hpet clock functionality in hyperkit to support 64-bit counters?
I general PRs are always welcome, yes.
Why do you need a 64 -bit HPET though, are you seeing an issue?
While trying to make OSv unikernel to boot on hyperkit I discovered that the assert https://github.com/cloudius-systems/osv/blob/master/drivers/hpet.cc#L55 to verify the counter is 64-bit breaks. I actually disabled the assert which made OSv boot and run but eventually fail in another place after roughly 8 minutes. I am not really familiar with HPET but I am guessing disabling the assert is not the right way to fix it on OSv side. So I was wondering if it might be easier to support 64-bit counter on hyperkit side same way as QEMU supports. Looking at Linux implementation - https://github.com/torvalds/linux/blob/master/arch/x86/kernel/hpet.c - it seems that properly supporting HPET in both 32 and 64 bit mode might be pretty tricky judging the lines of code (1300) and some comments in there https://github.com/torvalds/linux/blob/master/arch/x86/kernel/hpet.c#L362-L384.
If FreeBSD bhyve supports 64bit HPET it should be relatively easier to backport. I would check that
On 5 Mar 2019, at 03:32, WALDEMAR KOZACZUK [email protected] wrote:
While trying to make OSv unikernel to boot on hyperkit I discovered that the assert https://github.com/cloudius-systems/osv/blob/master/drivers/hpet.cc#L55 to verify the counter is 64-bit breaks. I actually disabled the assert which made OSv boot and run but eventually fail in another place after roughly 8 minutes. I am not really familiar with HPET but I am guessing disabling the assert is not the right way to fix it on OSv side. So I was wondering if it might be easier to support 64-bit counter on hyperkit side same way as QEMU supports. Looking at Linux implementation - https://github.com/torvalds/linux/blob/master/arch/x86/kernel/hpet.c - it seems that properly supporting HPET in both 32 and 64 bit mode might be pretty tricky judging the lines of code (1300) and some comments in there https://github.com/torvalds/linux/blob/master/arch/x86/kernel/hpet.c#L362-L384.
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