mbox series

[0/2] Fix handling of h_set_dawr

Message ID 20190617071619.19360-1-sjitindarsingh@gmail.com
Headers show
Series Fix handling of h_set_dawr | expand

Message

Suraj Jitindar Singh June 17, 2019, 7:16 a.m. UTC
Series contains 2 patches to fix the host in kernel handling of the hcall
h_set_dawr.

First patch from Michael Neuling is just a resend added here for clarity.

Michael Neuling (1):
  KVM: PPC: Book3S HV: Fix r3 corruption in h_set_dabr()

Suraj Jitindar Singh (1):
  KVM: PPC: Book3S HV: Only write DAWR[X] when handling h_set_dawr in
    real mode

 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

Comments

Cédric Le Goater June 17, 2019, 9:06 a.m. UTC | #1
On 17/06/2019 09:16, Suraj Jitindar Singh wrote:
> Series contains 2 patches to fix the host in kernel handling of the hcall
> h_set_dawr.
> 
> First patch from Michael Neuling is just a resend added here for clarity.
> 
> Michael Neuling (1):
>   KVM: PPC: Book3S HV: Fix r3 corruption in h_set_dabr()
> 
> Suraj Jitindar Singh (1):
>   KVM: PPC: Book3S HV: Only write DAWR[X] when handling h_set_dawr in
>     real mode



Reviewed-by: Cédric Le Goater <clg@kaod.org>

and 

Tested-by: Cédric Le Goater <clg@kaod.org>


but I see slowdowns in nested as if the IPIs were not delivered. Have we
touch this part in 5.2 ? 

Thanks,

C.
Suraj Jitindar Singh June 20, 2019, 1:45 a.m. UTC | #2
On Mon, 2019-06-17 at 11:06 +0200, Cédric Le Goater wrote:
> On 17/06/2019 09:16, Suraj Jitindar Singh wrote:
> > Series contains 2 patches to fix the host in kernel handling of the
> > hcall
> > h_set_dawr.
> > 
> > First patch from Michael Neuling is just a resend added here for
> > clarity.
> > 
> > Michael Neuling (1):
> >   KVM: PPC: Book3S HV: Fix r3 corruption in h_set_dabr()
> > 
> > Suraj Jitindar Singh (1):
> >   KVM: PPC: Book3S HV: Only write DAWR[X] when handling h_set_dawr
> > in
> >     real mode
> 
> 
> 
> Reviewed-by: Cédric Le Goater <clg@kaod.org>
> 
> and 
> 
> Tested-by: Cédric Le Goater <clg@kaod.org>
> 
> 
> but I see slowdowns in nested as if the IPIs were not delivered. Have
> we
> touch this part in 5.2 ? 

Hi,

I've seen the same and tracked it down to decrementer exceptions not
being delivered when the guest is using large decrementer. I've got a
patch I'm about to send so I'll CC you.

Another option is to disable the large decrementer with:
-machine pseries,cap-large-decr=false

Thanks,
Suraj

> 
> Thanks,
> 
> C.
>