mbox series

[J,0/2,v3] KVM: Improve SIGP architectural compliance (LP: 1959735)

Message ID 20220204151151.450613-1-frank.heimes@canonical.com
Headers show
Series KVM: Improve SIGP architectural compliance (LP: 1959735) | expand

Message

Frank Heimes Feb. 4, 2022, 3:11 p.m. UTC 
BugLink: https://bugs.launchpad.net/bugs/1959735

Linux as a guest operating system often doesn't have as stringent requirements
to architectural compliance as traditional operating systems that rely on it. 
Specifically, KVM implements the SIGP RESTART in a non-compliant way, 
as it reports a CPU state to be stopped after SIGP RESTART was issued, 
while it should report a busy condition until the CPU is really started.
This feature covers the necessary fixes/improvements to KVM SIGP processing.

v2: fixed hash, cherry picked from linux (instead of linux-next), based on 5.15.0-20.20
v3: changed order of cherry-picks

Eric Farman (2):
  KVM: s390: Simplify SIGP Set Arch handling
  KVM: s390: Add a routine for setting userspace CPU state

 arch/s390/kvm/kvm-s390.c |  6 +++---
 arch/s390/kvm/kvm-s390.h |  9 +++++++++
 arch/s390/kvm/sigp.c     | 14 +-------------
 3 files changed, 13 insertions(+), 16 deletions(-)

Comments

Krzysztof Kozlowski Feb. 4, 2022, 3:13 p.m. UTC | #1 
On 04/02/2022 16:11, frank.heimes@canonical.com wrote:
> BugLink: https://bugs.launchpad.net/bugs/1959735
> 
> Linux as a guest operating system often doesn't have as stringent requirements
> to architectural compliance as traditional operating systems that rely on it. 
> Specifically, KVM implements the SIGP RESTART in a non-compliant way, 
> as it reports a CPU state to be stopped after SIGP RESTART was issued, 
> while it should report a busy condition until the CPU is really started.
> This feature covers the necessary fixes/improvements to KVM SIGP processing.
> 
> v2: fixed hash, cherry picked from linux (instead of linux-next), based on 5.15.0-20.20
> v3: changed order of cherry-picks


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>


Best regards,
Krzysztof
Tim Gardner Feb. 4, 2022, 4:29 p.m. UTC | #2 
Acked-by: Tim Gardner <tim.gardner@canonical.com>

On 2/4/22 8:11 AM, frank.heimes@canonical.com wrote:
> BugLink: https://bugs.launchpad.net/bugs/1959735
> 
> Linux as a guest operating system often doesn't have as stringent requirements
> to architectural compliance as traditional operating systems that rely on it.
> Specifically, KVM implements the SIGP RESTART in a non-compliant way,
> as it reports a CPU state to be stopped after SIGP RESTART was issued,
> while it should report a busy condition until the CPU is really started.
> This feature covers the necessary fixes/improvements to KVM SIGP processing.
> 
> v2: fixed hash, cherry picked from linux (instead of linux-next), based on 5.15.0-20.20
> v3: changed order of cherry-picks
> 
> Eric Farman (2):
>    KVM: s390: Simplify SIGP Set Arch handling
>    KVM: s390: Add a routine for setting userspace CPU state
> 
>   arch/s390/kvm/kvm-s390.c |  6 +++---
>   arch/s390/kvm/kvm-s390.h |  9 +++++++++
>   arch/s390/kvm/sigp.c     | 14 +-------------
>   3 files changed, 13 insertions(+), 16 deletions(-)
>
Paolo Pisati Feb. 11, 2022, 10:31 a.m. UTC | #3 
On Fri, Feb 04, 2022 at 04:11:49PM +0100, frank.heimes@canonical.com wrote:
> BugLink: https://bugs.launchpad.net/bugs/1959735