On Mon, Mar 13, 2023 at 12:26:56PM +0000, Michael Kelley (LINUX) wrote: > From: Saurabh Singh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx> Sent: Sunday, March 12, 2023 11:16 PM > > > > On Mon, Mar 13, 2023 at 02:33:53AM +0000, Michael Kelley (LINUX) wrote: > > > From: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx> Sent: Thursday, February 23, > > 2023 3:29 AM > > > > > > > > Update the driver to support Devicetree boot as well along with ACPI. > > > > At present the Devicetree parsing only provides the mmio region info > > > > and is not the exact copy of ACPI parsing. This is sufficient to cater > > > > all the current Devicetree usecases for VMBus. > > > > > > > > Currently Devicetree is supported only for x86 systems. > > > > > > > > Signed-off-by: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx> > > > > --- > > > > [V7] > > > > - Use cpu_addr instead of bus_addr > > > > > > > > drivers/hv/Kconfig | 6 +++-- > > > > drivers/hv/vmbus_drv.c | 57 ++++++++++++++++++++++++++++++++++++++++-- > > > > 2 files changed, 59 insertions(+), 4 deletions(-) > > > > > > > > diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig > > > > index 0747a8f1fcee..1a55bf32d195 100644 > > > > --- a/drivers/hv/Kconfig > > > > +++ b/drivers/hv/Kconfig > > > > @@ -4,11 +4,13 @@ menu "Microsoft Hyper-V guest support" > > > > > > > > config HYPERV > > > > tristate "Microsoft Hyper-V client drivers" > > > > - depends on ACPI && ((X86 && X86_LOCAL_APIC && HYPERVISOR_GUEST) \ > > > > - || (ARM64 && !CPU_BIG_ENDIAN)) > > > > + depends on (X86 && X86_LOCAL_APIC && HYPERVISOR_GUEST) \ > > > > + || (ACPI && ARM64 && !CPU_BIG_ENDIAN) > > > > select PARAVIRT > > > > select X86_HV_CALLBACK_VECTOR if X86 > > > > select VMAP_PFN > > > > + select OF if !ACPI > > > > + select OF_EARLY_FLATTREE if !ACPI > > > > help > > > > Select this option to run Linux as a Hyper-V client operating > > > > system. > > > > > > One further thing occurred to me. OF_EARLY_FLATTREE really depends > > > on OF instead of ACPI. The ACPI dependency is indirect through OF. So > > > I'd suggest doing > > > > > > select OF_EARLY_FLATTRE if OF > > > > > > to express the direct dependency. > > > > As you pointed out OF_EARLY_FLATTRE is anyway dependent on OF, and thus I > > feel this check is redundant. I see all the Kconfig options which enables > > both of these flags don't explicitly mention this dependency. > > > > > > > > Separately, I wonder if the "select OF if !ACPI" is even needed. It doesn't > > > hurt anything to leave it, but it seems like any config that doesn't > > > independently select either ACPI or OF is broken for reasons unrelated > > > to Hyper-V. I'm OK with leaving the select of OF if you want, so I'm > > > more just wondering than asserting it should be removed. I didn't > > > see "select OF if !ACPI" anywhere else in the Kconfig files, and it > > > seems like Hyper-V would not be the only environment where this > > > is the expectation. > > > > Ok I can remove the !ACPI dependency. Hope kernel size increase due to both > > the code compiled in shouldn't be problem for ACPI systems. > > And here if config doesn't select ACPI or OF it will assume OF, which is > > better then selecting none of them. > > > > > > To address both of your comments I feel below will be sufficient: > > select OF > > select OF_EARLY_FLATTRE > > Actually, that's not what I was thinking. :-) I was thinking for the Hyper-V > Kconfig to be silent on selecting OF, just like it is silent on selecting ACPI. > Whoever is configuring the kernel build would separately be selecting > ACPI, or OF, or both, depending on their needs. I don't think the Hyper-V > Kconfig should always be selecting OF, because of the reason you noted -- > it drags in code that is not needed for normal VTL 0 usage. If you take > that approach, then > > select OF_EARLY_FLATTREE if OF > > is appropriate. Thanks for clarifying, I will fix this in next vesrion. Regards, Saurabh > > Michael > > > > > > > > > Regards, > > Saurabh > > > > > > > > Michael
