[PATCH hyperv-next v2 0/2] x86/hyperv: VTL mode reboot fixes

Roman Kisel posted 2 patches 9 months, 4 weeks ago
There is a newer version of this series
arch/x86/hyperv/hv_vtl.c | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
[PATCH hyperv-next v2 0/2] x86/hyperv: VTL mode reboot fixes
Posted by Roman Kisel 9 months, 4 weeks ago
The first patch defines a specialized machine emergency restart
callback not to write to the physical address of 0x472 which is
what the native_machine_emergency_restart() does unconditionally.

I first wanted to tweak that function[1], and in the course of
the discussion it looked as the risks of doing that would
outweigh the benefit: the bare-metal systems have likely adopted
that behavior as a standard although I could not find any mentions
of that magic address in the UEFI+ACPI specification.

The second patch removes the need to always supply "reboot=t"
to the kernel command line in the OpenHCL bootloader[2]. There is
no other option at the moment; when/if it appears the newly added
callback's code can be adjusted as required.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>

[1] https://lore.kernel.org/all/20250109204352.1720337-1-romank@linux.microsoft.com/
[2] https://github.com/microsoft/openvmm/blob/7a9d0e0a00461be6e5f3267af9ea54cc7157c900/openhcl/openhcl_boot/src/main.rs#L139

[V2]:
    - Fixed the warning from the kernel robot about using C23.
      ** Thank you, kernel robot!**

    - Tightened up wording in the comments and the commit
      descriptions.
      ** Thank you, Saurabh!**

    - Dropped the CC: stable tag as there is no specific commit
      this patch series fixes.
      ** Thank you, Saurabh!**

[V1]: https://lore.kernel.org/linux-hyperv/20250117210702.1529580-1-romank@linux.microsoft.com/

Roman Kisel (2):
  x86/hyperv: VTL mode emergency restart callback
  x86/hyperv: VTL mode callback for restarting the system

 arch/x86/hyperv/hv_vtl.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)


base-commit: 3a7f7785eae7cf012af128ca9e383c91e4955354
-- 
2.43.0
Re: [PATCH hyperv-next v2 0/2] x86/hyperv: VTL mode reboot fixes
Posted by Ingo Molnar 9 months, 4 weeks ago
* Roman Kisel <romank@linux.microsoft.com> wrote:

> Roman Kisel (2):
>   x86/hyperv: VTL mode emergency restart callback
>   x86/hyperv: VTL mode callback for restarting the system

A: These two patch titles verbs.
...
...
B: These two patch titles are missing verbs.

Like me you prefer B too, right? If so, please add back the missing 
verbs to the titles. I suggest "Add"/"Introduce", and "Call". Thank you!

	Ingo
Re: [PATCH hyperv-next v2 0/2] x86/hyperv: VTL mode reboot fixes
Posted by Roman Kisel 9 months, 3 weeks ago

On 2/21/2025 5:04 AM, Ingo Molnar wrote:
> 
> * Roman Kisel <romank@linux.microsoft.com> wrote:
> 
>> Roman Kisel (2):
>>    x86/hyperv: VTL mode emergency restart callback
>>    x86/hyperv: VTL mode callback for restarting the system
> 
> A: These two patch titles verbs.
> ...
> ...
> B: These two patch titles are missing verbs.
> 
> Like me you prefer B too, right? If so, please add back the missing
> verbs to the titles. I suggest "Add"/"Introduce", and "Call". Thank you!

Right :) Thank you for taking the time to help me, much appreciated!

> 
> 	Ingo

-- 
Thank you,
Roman