On Mon, Aug 05, 2024 at 03:01:58AM +0000, Michael Kelley wrote:

From: Roman Kisel <redacted> Sent: Friday, July 26, 2024 3:59 PM

quoted

Kconfig dependencies for arm64 guests on Hyper-V require that be ACPI enabled,
and limit VTL mode to x86/x64. To enable VTL mode on arm64 as well, update the
dependencies. Since VTL mode requires DeviceTree instead of ACPI, don't require
arm64 guests on Hyper-V to have ACPI.

Signed-off-by: Roman Kisel <redacted>
---
 drivers/hv/Kconfig | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 862c47b191af..a5cd1365e248 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig

@@ -5,7 +5,7 @@ menu "Microsoft Hyper-V guest support"
 config HYPERV
 	tristate "Microsoft Hyper-V client drivers"
 	depends on (X86 && X86_LOCAL_APIC && HYPERVISOR_GUEST) \
-		|| (ACPI && ARM64 && !CPU_BIG_ENDIAN)
+		|| (ARM64 && !CPU_BIG_ENDIAN)
 	select PARAVIRT
 	select X86_HV_CALLBACK_VECTOR if X86
 	select OF_EARLY_FLATTREE if OF

@@ -15,7 +15,7 @@ config HYPERV

 config HYPERV_VTL_MODE
 	bool "Enable Linux to boot in VTL context"
-	depends on X86_64 && HYPERV
+	depends on HYPERV
 	depends on SMP
 	default n
 	help

@@ -31,7 +31,7 @@ config HYPERV_VTL_MODE

 	  Select this option to build a Linux kernel to run at a VTL other than
 	  the normal VTL0, which currently is only VTL2.  This option
-	  initializes the x86 platform for VTL2, and adds the ability to boot
+	  initializes the kernel to run in VTL2, and adds the ability to boot
 	  secondary CPUs directly into 64-bit context as required for VTLs other
 	  than 0.  A kernel built with this option must run at VTL2, and will
 	  not run as a normal guest.
--

2.34.1

In v2 of this patch, I suggested [1] making a couple additional minor changes
so that kernels built *without* HYPER_VTL_MODE would still require
ACPI.  Did that suggestion not work out?  If that's the case, I'm curious
about what goes wrong.

Hi Michael/Roman,
I was considering making HYPERV_VTL_MODE depend on CONFIG_OF. That should address
above concern as well. Do you see any potential issue with it.

- Saurabh