[PATCH 0/5] Drivers: hv: Fix NEED_RESCHED_LAZY and use common APIs

[Nuno Das Neves]

On 8/25/2025 1:06 PM, Sean Christopherson wrote:
> Fix a bug where MSHV root partitions don't honor NEED_RESCHED_LAZY, and then
> deduplicate the TIF related MSHV code by turning the "kvm" entry APIs into
> more generic "virt" APIs (which ideally would have been done when MSHV root
> support was added).
> 
> Assuming all is well, maybe this could go through the tip tree?
> 
> The Hyper-V stuff and non-x86 architectures are compile-tested only.
> 

Thanks Sean, I can test the root partition changes.

A similar change will be needed in mshv_vtl_main.c since it also calls
mshv_do_pre_guest_mode_work() (hence the "common" in mshv_common.c).

Also, is it possible to make all the mshv driver changes in a single patch?
It seems like it would be cleaner than refactoring it in patches 1 & 2 and
then deleting all the refactored code in patch 5.

Thanks
Nuno

> Sean Christopherson (5):
>   Drivers: hv: Move TIF pre-guest work handling fully into mshv_common.c
>   Drivers: hv: Handle NEED_RESCHED_LAZY before transferring to guest
>   entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM
>     proper
>   entry: Rename "kvm" entry code assets to "virt" to genericize APIs
>   Drivers: hv: Use common "entry virt" APIs to do work before running
>     guest
> 
>  MAINTAINERS                                 |  2 +-
>  arch/arm64/kvm/Kconfig                      |  2 +-
>  arch/arm64/kvm/arm.c                        |  3 +-
>  arch/loongarch/kvm/Kconfig                  |  2 +-
>  arch/loongarch/kvm/vcpu.c                   |  3 +-
>  arch/riscv/kvm/Kconfig                      |  2 +-
>  arch/riscv/kvm/vcpu.c                       |  3 +-
>  arch/x86/kvm/Kconfig                        |  2 +-
>  arch/x86/kvm/vmx/vmx.c                      |  1 -
>  arch/x86/kvm/x86.c                          |  3 +-
>  drivers/hv/Kconfig                          |  1 +
>  drivers/hv/mshv.h                           |  2 --
>  drivers/hv/mshv_common.c                    | 22 ---------------
>  drivers/hv/mshv_root_main.c                 | 31 ++++-----------------
>  include/linux/{entry-kvm.h => entry-virt.h} | 19 +++++--------
>  include/linux/kvm_host.h                    | 17 +++++++++--
>  include/linux/rcupdate.h                    |  2 +-
>  kernel/entry/Makefile                       |  2 +-
>  kernel/entry/{kvm.c => virt.c}              | 15 ++++------
>  kernel/rcu/tree.c                           |  6 ++--
>  virt/kvm/Kconfig                            |  2 +-
>  21 files changed, 49 insertions(+), 93 deletions(-)
>  rename include/linux/{entry-kvm.h => entry-virt.h} (83%)
>  rename kernel/entry/{kvm.c => virt.c} (66%)
> 
> 
> base-commit: 1b237f190eb3d36f52dffe07a40b5eb210280e00