INACCESSIBLE_BOOT_DEVICE after enabling Hyper-V in Windows 10 on Late-2015 27" 5k iMac

ozziepeeps1982 wrote:

macOS 10.12.4 re-enables VT-d in EFI, meaning that Hyper-V works again, without needing to do the rEFId stuff I described above.

About the security content of macOS Sierra 10.12.4, Security Update 2017-001 El Capitan, and Security Update 2017-001 Yo…

EFI

Available for: macOS Sierra 10.12.3

Impact: A malicious Thunderbolt adapter may be able to recover the FileVault 2 encryption password

Description: An issue existed in the handling of DMA. This issue was addressed by enabling VT-d in EFI.

CVE-2016-7585: Ulf Frisk (@UlfFrisk)

Finally. 😎

Hi everyone.

I've got Hyper-V working reliably under Windows 10 installed via Bootcamp on a 2016 MBP without TouchBar. The steps are relatively advanced, but were easy to follow and most people on this thread should be comfortable. You install and EFI boot manager called rEFInd (it's the "modern" successor to a tool I used to use on my old MacBook Air called rEFIt). By tinkering with rEFInd's configuration you can get it to EFI-boot Windows with the hypervisor enabled.

Follow the instructions here, CAREFULLY: http://nuts4.net/post/hack-force-vt-x-to-be-always-on-when-booting-to-windows-on -your-macbook

I also followed the steps in this article about enabling "legacy safe mode" for Windows 10 (allowing me to press the F8 key during boot if anything goes wrong): https://medium.com/@naokisatoname/newer-mac-windows-10-on-boot-camp-hyper-v-enab led-infinite-spinning-circle-5631b36f6d1…

The net result is a clean install of W10 via Bootcamp, with working Hyper-V. I need to use rEFInd as my boot manager to EFI-boot Windows, but that's totally fine in my book.

I hope this helps people. I intend to cross post this solution on the other linked threads to get the word out there.

Regards,

Mark

@Loner T, so basically they fixed it because it affected their own software, shows they don't care one bit or out of touch with how their users use their products.

I knew it was possible because the processor supported it. I'll give it a try and report if it works.

Exocomp-01 wrote:

@Loner T, so basically they fixed it because it affected their own software, shows they don't care one bit or out of touch with how their users use their products.

Doesn't show anything of the sort, Windows is not their product.

Exocomp-01 wrote:

@Loner T, so basically they fixed it because it affected their own software, shows they don't care one bit or out of touch with how their users use their products.

I tend to look at it differently. Apple has products, product features are deprecated and added, as necessary. VT-d is explained in intel-virtualization-technology-for-directed-io-vt-d . The CSM-BIOS layer accomplished this function partially till the 2014 Macs. 2015 and later Macs no longer have CSM, so this solves the current issue. This was an easier solution than any other method in EFI. I assume Apple will not reverse this in the future and write their own flavor of IO management. The extract from the Intel link that is relevant to BIOS is

BIOS requirements for the platform

BIOS enabling is required for VT-d use. The BIOS needs to expose VT-d capabilities (e.g. # of DMA remap engines etc) to the VMM through the ACPI table.

Exocomp-01 wrote:

I knew it was possible because the processor supported it.

One more example which is in the same category is AirPlay vs WiDi. Intel supports WiDi, but Apple disables it.

Post back with your testing results. ozziepeeps1982's results are very encouraging.

I can still confirm good mileage here. I'm dual booting Windows 10 Creators Update and macOS 10.12.4. I'm running Visual Studio 2017 mobile device emulators (via Hyper-V) under Win 10. All working great! This is on a 2016 MBP with Fn keys. I hope other people have the same results after installing the macOS update.

@Csound1, I disagree - Apple is a hardware company. They've actually stopped making money on most software they write like the OS. Regardless people use their products and run Windows on it and they need to cater to those customers if they still want to sell products, that is basically the bottom line.

Exocomp-01 wrote:

@Csound1, I disagree - Apple is a hardware company. They've actually stopped making money on most software they write like the OS. Regardless people use their products and run Windows on it and they need to cater to those customers if they still want to sell products, that is basically the bottom line.

What does that have to do with Microsofts product?

Exocomp-01 wrote:

Apple is a hardware company. They've actually stopped making money on most software they write like the OS.

Software is thrown in, and it's cost is built into the hardware. Specifically for macOS, you pay premium yen for Apple HW on which it is licensed. The EULA prohibits running macOS on non-apple HW (despite Hackint0sh). It is also a matter of perception. Apple makes better (-engineered) HW and users who want to pay a premium, prefer Apple HW over, say, Dell or Sony or HP or Lenovo. To me, Windows is windows-tinting on a Maserati. 😉. It is also a vicious circle in terms of Application software portability, for example, Microsoft Office exists on both, but Visio does not, so I need Windows because the corporate standard says - Use Visio (not OmniGraffle). This subject deserves it's own discussion.

Exocomp-01 wrote:

Regardless people use their products and run Windows on it and they need to cater to those customers if they still want to sell products, that is basically the bottom line.

It depends on how 'large' such a segment of the population is. There is a significant difference between .1% of all Macs sold vs 20% of all Macs sold using Hyper-V. Also, product and market distinction is a factor to consider.

Just my 2c.

Exactly same issue in here . tried many things but no luck. Tried with iMac 2011 and it is working fine but late 2015 doesn't work.have you foudn a solution ?

I'm in the same boat fellas, as soon as I install Hyper-V on iMac 27 Retina, I get INACCESSIBLE_BOOT_DEVICE

Please see Why is VT-x disabled in Windows 10? . The references to CSM-BIOS do not apply, because W10 is EFI/UEFI on 2015 Macs.

Please also see If I reboot to Windows directly from Windows (bootcamp options), I cannot launch a vm in Hyper-V and be aware that bless is no longer supported on El Capitan.

References

NetBoot, NetInstall, and NetRestore requirements in OS X El Capitan - Apple Support

https://derflounder.wordpress.com/2015/09/05/netbooting-and-system-integrity-pro tection/

Since I have the iMac late 2015 model looks like I'm out of luck, the System Preferences -> Startup Disk method did not work, I get the same error as before. 😟

Same problem here, very frustrated.

I am currently running Windows 10 Insider Build 14295 on Mid 2015 Macbook Pro 15" with BootCamp 6.0, I cannot even enable the Hyper-V in Windows Features, it says "Virtualization support is disabled in firmware". Of course, the "boot to mac > restart to windows" trick doesn't work here since Windows 10 uses UEFi instead of legacy BIOS.

Any idea how to fix this, or are we at mercy of Apple's software update which might never come?

SOLVED / FIXED...

OK, this is what fixed my problem. I read it somewhere somebody tried plugging in a Thunderbolt-to-Ethernet Adaptor and Hyper-V can be magically enabled. I tried plugging in a USB-to-Ethernet Adaptor and it did the same trick. Now I can enable Hyper-V and Windows 10 Mobile emulator worked like charm.

Seems like some sort of Ethernet adaptor is required for Mac UEFI to enable Hypervisor virtualization...