From: Wei Liu <wei.liu@kernel.org>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu@kernel.org>,
Linux on Hyper-V List <linux-hyperv@vger.kernel.org>,
virtualization@lists.linux-foundation.org,
Linux Kernel List <linux-kernel@vger.kernel.org>,
Michael Kelley <mikelley@microsoft.com>,
Vineeth Pillai <viremana@linux.microsoft.com>,
Sunil Muthuswamy <sunilmut@microsoft.com>,
Nuno Das Neves <nunodasneves@linux.microsoft.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>
Subject: Re: [PATCH v2 03/17] Drivers: hv: vmbus: skip VMBus initialization if Linux is root
Date: Fri, 13 Nov 2020 14:51:06 +0000 [thread overview]
Message-ID: <20201113145106.k4ekiw5cu427e3wi@liuwe-devbox-debian-v2> (raw)
In-Reply-To: <87imaay4w9.fsf@vitty.brq.redhat.com>
On Thu, Nov 12, 2020 at 04:24:38PM +0100, Vitaly Kuznetsov wrote:
> Wei Liu <wei.liu@kernel.org> writes:
>
> > There is no VMBus and the other infrastructures initialized in
> > hv_acpi_init when Linux is running as the root partition.
> >
> > Signed-off-by: Wei Liu <wei.liu@kernel.org>
> > ---
> > drivers/hv/vmbus_drv.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> > index 4fad3e6745e5..37c4d3a28309 100644
> > --- a/drivers/hv/vmbus_drv.c
> > +++ b/drivers/hv/vmbus_drv.c
> > @@ -2612,6 +2612,9 @@ static int __init hv_acpi_init(void)
> > if (!hv_is_hyperv_initialized())
> > return -ENODEV;
> >
> > + if (hv_root_partition)
> > + return -ENODEV;
> > +
>
> Nit: any particular reason why we need to return an error from here? I'd
> suggest we 'return 0;' if it doesn't break anything (we're still running
> on Hyper-V, it's just a coincedence that there's nothing to do here,
> eventually we may get some devices/handlers I guess. Also, there's going
> to be server-side Vmbus eventually, we may as well initialize it here.
Returning 0 should be fine. It is not likely to make any practical
difference at this stage.
Not sure what you mean by server-side Vmbus. If you mean Vmbus on the
host, yes, there will be. The initialization is, again, a bit different
there. You will see why when my colleague post /dev/mshv code. The long
term goal is to refactor the Vmbus initialization code to work in all
scenarios. We are not there yet though.
Wei.
>
> > init_completion(&probe_event);
> >
> > /*
>
> --
> Vitaly
>
next prev parent reply other threads:[~2020-11-13 14:51 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-05 16:57 [PATCH v2 00/17] Introducing Linux root partition support for Microsoft Hypervisor Wei Liu
2020-11-05 16:57 ` [PATCH v2 01/17] asm-generic/hyperv: change HV_CPU_POWER_MANAGEMENT to HV_CPU_MANAGEMENT Wei Liu
2020-11-12 15:14 ` Vitaly Kuznetsov
2020-11-05 16:57 ` [PATCH v2 02/17] x86/hyperv: detect if Linux is the root partition Wei Liu
2020-11-05 19:16 ` kernel test robot
2020-11-12 11:42 ` Wei Liu
2020-11-12 11:46 ` Wei Liu
2020-11-12 12:22 ` Wei Liu
2020-11-05 20:23 ` kernel test robot
2020-11-12 15:16 ` Vitaly Kuznetsov
2020-11-12 15:51 ` Wei Liu
2020-11-05 16:58 ` [PATCH v2 03/17] Drivers: hv: vmbus: skip VMBus initialization if Linux is root Wei Liu
2020-11-12 15:24 ` Vitaly Kuznetsov
2020-11-13 14:51 ` Wei Liu [this message]
2020-11-05 16:58 ` [PATCH v2 04/17] iommu/hyperv: don't setup IRQ remapping when running as root Wei Liu
2020-11-12 15:27 ` Vitaly Kuznetsov
2020-11-13 14:53 ` Wei Liu
2020-11-05 16:58 ` [PATCH v2 05/17] clocksource/hyperv: use MSR-based access if " Wei Liu
2020-11-12 9:56 ` Daniel Lezcano
2020-11-12 11:24 ` Wei Liu
2020-11-12 11:40 ` Daniel Lezcano
2020-11-12 11:42 ` Wei Liu
2020-11-12 15:30 ` Vitaly Kuznetsov
2020-11-12 15:52 ` Wei Liu
2020-11-05 16:58 ` [PATCH v2 06/17] x86/hyperv: allocate output arg pages if required Wei Liu
2020-11-12 15:35 ` Vitaly Kuznetsov
2020-11-13 15:05 ` Wei Liu
2020-11-05 16:58 ` [PATCH v2 07/17] x86/hyperv: extract partition ID from Microsoft Hypervisor if necessary Wei Liu
2020-11-05 20:07 ` kernel test robot
2020-11-12 11:54 ` Wei Liu
2020-11-05 20:20 ` kernel test robot
2020-11-12 15:44 ` Vitaly Kuznetsov
2020-11-13 15:21 ` Wei Liu
2020-11-05 16:58 ` [PATCH v2 08/17] x86/hyperv: handling hypercall page setup for root Wei Liu
2020-11-12 15:51 ` Vitaly Kuznetsov
2020-11-13 15:33 ` Wei Liu
2020-11-13 16:09 ` Wei Liu
2020-11-13 16:16 ` Vitaly Kuznetsov
2020-11-05 16:58 ` [PATCH v2 09/17] x86/hyperv: provide a bunch of helper functions Wei Liu
2020-11-12 15:57 ` Vitaly Kuznetsov
2020-11-13 15:51 ` Wei Liu
2020-11-13 16:13 ` Vitaly Kuznetsov
2020-11-16 11:41 ` Wei Liu
2020-11-05 16:58 ` [PATCH v2 10/17] x86/hyperv: implement and use hv_smp_prepare_cpus Wei Liu
2020-11-12 16:44 ` Vitaly Kuznetsov
2020-11-13 15:56 ` Wei Liu
2020-11-05 16:58 ` [PATCH v2 11/17] asm-generic/hyperv: update hv_msi_entry Wei Liu
2020-11-05 16:58 ` [PATCH v2 12/17] asm-generic/hyperv: update hv_interrupt_entry Wei Liu
2020-11-05 16:58 ` [PATCH v2 13/17] asm-generic/hyperv: introduce hv_device_id and auxiliary structures Wei Liu
2020-11-05 16:58 ` [PATCH v2 14/17] asm-generic/hyperv: import data structures for mapping device interrupts Wei Liu
2020-11-05 16:58 ` [PATCH v2 15/17] x86/hyperv: implement an MSI domain for root partition Wei Liu
2020-11-12 13:50 ` Wei Liu
2020-11-05 16:58 ` [PATCH v2 16/17] x86/ioapic: export a few functions and data structures via io_apic.h Wei Liu
2020-11-12 11:39 ` Wei Liu
2020-11-05 16:58 ` [PATCH v2 17/17] x86/hyperv: handle IO-APIC when running as root Wei Liu
2020-11-12 16:56 ` Vitaly Kuznetsov
2020-11-13 16:01 ` Wei Liu
2020-11-13 16:04 ` Wei Liu
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