From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Wei Liu <wei.liu@kernel.org>,
Linux on Hyper-V List <linux-hyperv@vger.kernel.org>
Cc: 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>,
Wei Liu <wei.liu@kernel.org>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH v2 05/17] clocksource/hyperv: use MSR-based access if running as root
Date: Thu, 12 Nov 2020 16:30:57 +0100 [thread overview]
Message-ID: <87d00iy4lq.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <20201105165814.29233-6-wei.liu@kernel.org>
Wei Liu <wei.liu@kernel.org> writes:
> Signed-off-by: Wei Liu <wei.liu@kernel.org>
In the missing commit message I'd like to see why we don't use 'TSC
page' clocksource for the root partition. My guess would be that it's
not available and actually we're supposed to use raw TSC value (because
root partitions never migrate) but please spell it out.
> ---
> drivers/clocksource/hyperv_timer.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
> index ba04cb381cd3..269a691bd2c4 100644
> --- a/drivers/clocksource/hyperv_timer.c
> +++ b/drivers/clocksource/hyperv_timer.c
> @@ -426,6 +426,9 @@ static bool __init hv_init_tsc_clocksource(void)
> if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE))
> return false;
>
> + if (hv_root_partition)
> + return false;
> +
> hv_read_reference_counter = read_hv_clock_tsc;
> phys_addr = virt_to_phys(hv_get_tsc_page());
--
Vitaly
next prev parent reply other threads:[~2020-11-12 15:31 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
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 [this message]
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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