Page MenuHomeFreeBSD

FreeBSD enablement for ARM64 in Hyper-V
ClosedPublic

Authored by schakrabarti_microsoft.com on Sep 6 2022, 1:07 PM.

Details

Summary

These changes are part of the large review, which includes : D36256 , D36052.
The changes are to refactor the code of vmbus.c and hyperv.c to keep minimal arch specific codes there and have them in separate files in x86/ arm64/ .
x86 is a new directory, which contains codes for x86 / x86_64. Instead of repeating the same codes in existing amd64/ and i386/, this approach reduced the
repetition.

Diff Detail

Repository
rG FreeBSD src repository
Lint
Lint Not Applicable
Unit
Tests Not Applicable

Event Timeline

This revision is now accepted and ready to land.Sep 29 2022, 8:12 AM
mmel added inline comments.
sys/dev/hyperv/vmbus/aarch64/hyperv_machdep.c
61

But who will check if the target supports PSCI 1.2 (or later)? All my FDT-based boards hang inside the arm_smccc_1_2_hvc() function (none of them support PSCI 1.2).

sys/dev/hyperv/vmbus/aarch64/hyperv_aarch64.c
190

Huh, this function is obviously wrong and incomplete . We don't always run on a hypervisor and don't need SMCCC 1.2. There is no check for return values in hv_get_vpreg_128() .
I'm afraid this code was newer tested on a system without hyper-v

sys/dev/hyperv/vmbus/aarch64/hyperv_aarch64.c
190

Thanks for pointing, I have just found this problem. Will add a check with AcpiGbl_FADT HypervisorId to check if we are on Hyper-V or not ,
based on that will return.
Proposed change:
bool
hyperv_identify_features(void)
{
struct hv_get_vp_registers_output result;

        if (AcpiGbl_FADT.HypervisorId == "MsHyperv")
	   vm_guest = VM_GUEST_HV;
        else
            return (False);

hv_get_vpreg_128(CPUID_LEAF_HV_FEATURES, &result);
hyperv_features = result.as32.a;
hv_get_vpreg_128(CPUID_LEAF_HV_IDENTITY, &result);
hyperv_ver_major = result.as32.b >> 16;
hv_get_vpreg_128(CPUID_LEAF_HV_RECOMMENDS, &result);
hyperv_recommends = result.as32.a;
return (true);
}
will put this change, which should solve the problem.

Will put the

sys/dev/hyperv/vmbus/aarch64/hyperv_aarch64.c
190

WIll put the new patch for review by tomorrow.