1. Patchew
  2. linux
  3. View series

[PATCH] clocksource/drivers/hyperv: use Hyper-V's page size to calculate PFN

Anirudh Rayabharam posted 1 patch 3 years, 5 months ago 
drivers/clocksource/hyperv_timer.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
[PATCH] clocksource/drivers/hyperv: use Hyper-V's page size to calculate PFN
Posted by Anirudh Rayabharam 3 years, 5 months ago 
__phys_to_pfn() will return a PFN based on the guest page size, which might
be different from Hyper-V's page size that is always 4K. The PFN for the
TSC page always needs to be a Hyper-V PFN.

Use HVPFN_DOWN() to calculate the PFN of the TSC page from the physical
address.

Reported-by: Michael Kelley (LINUX) <mikelley@microsoft.com>
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
---
 drivers/clocksource/hyperv_timer.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index 11332c82d1af..18de1f439ffd 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -21,6 +21,7 @@
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/acpi.h>
+#include <linux/hyperv.h>
 #include <clocksource/hyperv_timer.h>
 #include <asm/hyperv-tlfs.h>
 #include <asm/mshyperv.h>
@@ -412,7 +413,7 @@ static void resume_hv_clock_tsc(struct clocksource *arg)
 	/* Re-enable the TSC page */
 	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
 	tsc_msr.enable = 1;
-	tsc_msr.pfn = __phys_to_pfn(phys_addr);
+	tsc_msr.pfn = HVPFN_DOWN(phys_addr);
 	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
 }
 
@@ -532,7 +533,7 @@ static bool __init hv_init_tsc_clocksource(void)
 	 */
 	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
 	tsc_msr.enable = 1;
-	tsc_msr.pfn = __phys_to_pfn(phys_addr);
+	tsc_msr.pfn = HVPFN_DOWN(phys_addr);
 	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
 
 	clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
-- 
2.34.1
RE: [PATCH] clocksource/drivers/hyperv: use Hyper-V's page size to calculate PFN
Posted by Michael Kelley (LINUX) 3 years, 5 months ago 
From: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Sent: Thursday, November 3, 2022 8:24 AM
> 
> __phys_to_pfn() will return a PFN based on the guest page size, which might
> be different from Hyper-V's page size that is always 4K. The PFN for the
> TSC page always needs to be a Hyper-V PFN.
> 
> Use HVPFN_DOWN() to calculate the PFN of the TSC page from the physical
> address.
> 
> Reported-by: Michael Kelley (LINUX) <mikelley@microsoft.com>
> Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
> ---
>  drivers/clocksource/hyperv_timer.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
> index 11332c82d1af..18de1f439ffd 100644
> --- a/drivers/clocksource/hyperv_timer.c
> +++ b/drivers/clocksource/hyperv_timer.c
> @@ -21,6 +21,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/irq.h>
>  #include <linux/acpi.h>
> +#include <linux/hyperv.h>
>  #include <clocksource/hyperv_timer.h>
>  #include <asm/hyperv-tlfs.h>
>  #include <asm/mshyperv.h>
> @@ -412,7 +413,7 @@ static void resume_hv_clock_tsc(struct clocksource *arg)
>  	/* Re-enable the TSC page */
>  	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
>  	tsc_msr.enable = 1;
> -	tsc_msr.pfn = __phys_to_pfn(phys_addr);
> +	tsc_msr.pfn = HVPFN_DOWN(phys_addr);
>  	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
>  }
> 
> @@ -532,7 +533,7 @@ static bool __init hv_init_tsc_clocksource(void)
>  	 */
>  	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
>  	tsc_msr.enable = 1;
> -	tsc_msr.pfn = __phys_to_pfn(phys_addr);
> +	tsc_msr.pfn = HVPFN_DOWN(phys_addr);
>  	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
> 
>  	clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
> --
> 2.34.1

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Re: [PATCH] clocksource/drivers/hyperv: use Hyper-V's page size to calculate PFN
Posted by Wei Liu 3 years, 5 months ago 
On Thu, Nov 03, 2022 at 03:34:23PM +0000, Michael Kelley (LINUX) wrote:
> From: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Sent: Thursday, November 3, 2022 8:24 AM
> > 
> > __phys_to_pfn() will return a PFN based on the guest page size, which might
> > be different from Hyper-V's page size that is always 4K. The PFN for the
> > TSC page always needs to be a Hyper-V PFN.
> > 
> > Use HVPFN_DOWN() to calculate the PFN of the TSC page from the physical
> > address.
> > 
> > Reported-by: Michael Kelley (LINUX) <mikelley@microsoft.com>
> > Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
> > ---
> >  drivers/clocksource/hyperv_timer.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
> > index 11332c82d1af..18de1f439ffd 100644
> > --- a/drivers/clocksource/hyperv_timer.c
> > +++ b/drivers/clocksource/hyperv_timer.c
> > @@ -21,6 +21,7 @@
> >  #include <linux/interrupt.h>
> >  #include <linux/irq.h>
> >  #include <linux/acpi.h>
> > +#include <linux/hyperv.h>
> >  #include <clocksource/hyperv_timer.h>
> >  #include <asm/hyperv-tlfs.h>
> >  #include <asm/mshyperv.h>
> > @@ -412,7 +413,7 @@ static void resume_hv_clock_tsc(struct clocksource *arg)
> >  	/* Re-enable the TSC page */
> >  	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
> >  	tsc_msr.enable = 1;
> > -	tsc_msr.pfn = __phys_to_pfn(phys_addr);
> > +	tsc_msr.pfn = HVPFN_DOWN(phys_addr);
> >  	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
> >  }
> > 
> > @@ -532,7 +533,7 @@ static bool __init hv_init_tsc_clocksource(void)
> >  	 */
> >  	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
> >  	tsc_msr.enable = 1;
> > -	tsc_msr.pfn = __phys_to_pfn(phys_addr);
> > +	tsc_msr.pfn = HVPFN_DOWN(phys_addr);
> >  	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
> > 
> >  	clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
> > --
> > 2.34.1
> 
> Reviewed-by: Michael Kelley <mikelley@microsoft.com>

Thank you both for the quick turnaround. I will just squash this patch
into the previous one.
Re: [PATCH] clocksource/drivers/hyperv: use Hyper-V's page size to calculate PFN
Posted by Daniel Lezcano 3 years, 4 months ago 
Hi,

On 03/11/2022 16:48, Wei Liu wrote:

[ ... ]

>> Reviewed-by: Michael Kelley <mikelley@microsoft.com>
> 
> Thank you both for the quick turnaround. I will just squash this patch
> into the previous one.

Can you point to the mailing list the squashed version ?



-- 
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
Re: [PATCH] clocksource/drivers/hyperv: use Hyper-V's page size to calculate PFN
Posted by Wei Liu 3 years, 4 months ago 
On Fri, Dec 02, 2022 at 01:33:17PM +0100, Daniel Lezcano wrote:
> 
> Hi,
> 
> On 03/11/2022 16:48, Wei Liu wrote:
> 
> [ ... ]
> 
> > > Reviewed-by: Michael Kelley <mikelley@microsoft.com>
> > 
> > Thank you both for the quick turnaround. I will just squash this patch
> > into the previous one.
> 
> Can you point to the mailing list the squashed version ?

The squashed patch is this one:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4ad1aa571214e8d6468a1806794d987b374b5a08

Thanks,
Wei.
Re: [PATCH] clocksource/drivers/hyperv: use Hyper-V's page size to calculate PFN
Posted by Daniel Lezcano 3 years, 4 months ago 
On 02/12/2022 19:14, Wei Liu wrote:
> On Fri, Dec 02, 2022 at 01:33:17PM +0100, Daniel Lezcano wrote:
>>
>> Hi,
>>
>> On 03/11/2022 16:48, Wei Liu wrote:
>>
>> [ ... ]
>>
>>>> Reviewed-by: Michael Kelley <mikelley@microsoft.com>
>>>
>>> Thank you both for the quick turnaround. I will just squash this patch
>>> into the previous one.
>>
>> Can you point to the mailing list the squashed version ?
> 
> The squashed patch is this one:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4ad1aa571214e8d6468a1806794d987b374b5a08

Thanks!

-- 
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

Patchew 2.1-devel-ea86937

© 2016 - 2026 Red Hat, Inc.