From: Janosch Frank <frankja@linux.ibm.com> To: Claudio Imbrenda <imbrenda@linux.ibm.com>, kvm@vger.kernel.org Cc: cohuck@redhat.com, borntraeger@de.ibm.com, thuth@redhat.com, pasic@linux.ibm.com, david@redhat.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 01/13] KVM: s390: pv: avoid stall notifications for some UVCs Date: Thu, 29 Jul 2021 11:58:39 +0200 [thread overview] Message-ID: <6bbeded3-ef94-6c83-f093-796d76b70792@linux.ibm.com> (raw) In-Reply-To: <20210728142631.41860-2-imbrenda@linux.ibm.com> On 7/28/21 4:26 PM, Claudio Imbrenda wrote: > Improve make_secure_pte to avoid stalls when the system is heavily > overcommitted. This was especially problematic in kvm_s390_pv_unpack, > because of the loop over all pages that needed unpacking. > > Also fix kvm_s390_pv_init_vm to avoid stalls when the system is heavily > overcommitted. Fixes tag? > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> > --- > arch/s390/kernel/uv.c | 11 ++++++++--- > arch/s390/kvm/pv.c | 2 +- > 2 files changed, 9 insertions(+), 4 deletions(-) > > diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c > index aeb0a15bcbb7..fd0faa51c1bb 100644 > --- a/arch/s390/kernel/uv.c > +++ b/arch/s390/kernel/uv.c > @@ -196,11 +196,16 @@ static int make_secure_pte(pte_t *ptep, unsigned long addr, > if (!page_ref_freeze(page, expected)) > return -EBUSY; > set_bit(PG_arch_1, &page->flags); > - rc = uv_call(0, (u64)uvcb); > + rc = __uv_call(0, (u64)uvcb); We should exchange rc with cc since that's what we get back from __uv_call(). Technically we always get a cc but for the other functions it's only ever 0/1 which translates to success/error so rc is ok. > page_ref_unfreeze(page, expected); > - /* Return -ENXIO if the page was not mapped, -EINVAL otherwise */ > - if (rc) > + /* > + * Return -ENXIO if the page was not mapped, -EINVAL for other errors. > + * If busy or partially completed, return -EAGAIN. > + */ > + if (rc == 1) > rc = uvcb->rc == 0x10a ? -ENXIO : -EINVAL; > + else if (rc > 1) > + rc = -EAGAIN; > return rc; Could you define the CCs in uv.h and check against the constants here so it's easier to understand that the rc > 1 checks against a "UV was busy please re-issue the call again" cc? Maybe also make it explicit for cc 2 and 3 instead of cc > 1 > } > > diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c > index c8841f476e91..e007df11a2fe 100644 > --- a/arch/s390/kvm/pv.c > +++ b/arch/s390/kvm/pv.c > @@ -196,7 +196,7 @@ int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc) > uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base; > uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var; > > - cc = uv_call(0, (u64)&uvcb); > + cc = uv_call_sched(0, (u64)&uvcb); > *rc = uvcb.header.rc; > *rrc = uvcb.header.rrc; > KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x", >
next prev parent reply other threads:[~2021-07-29 9:58 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-28 14:26 [PATCH v2 00/13] KVM: s390: pv: implement lazy destroy Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 01/13] KVM: s390: pv: avoid stall notifications for some UVCs Claudio Imbrenda 2021-07-29 9:58 ` Janosch Frank [this message] 2021-07-29 12:52 ` Claudio Imbrenda 2021-07-29 10:49 ` Cornelia Huck 2021-07-29 13:22 ` Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 02/13] KVM: s390: pv: leak the ASCE page when destroy fails Claudio Imbrenda 2021-07-29 10:41 ` Janosch Frank 2021-07-29 12:54 ` Claudio Imbrenda 2021-07-29 13:45 ` Janosch Frank 2021-07-28 14:26 ` [PATCH v2 03/13] KVM: s390: pv: properly handle page flags for protected guests Claudio Imbrenda 2021-07-29 11:43 ` Janosch Frank 2021-07-28 14:26 ` [PATCH v2 04/13] KVM: s390: pv: handle secure storage violations " Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 05/13] KVM: s390: pv: handle secure storage exceptions for normal guests Claudio Imbrenda 2021-07-29 12:17 ` Janosch Frank 2021-07-29 13:28 ` Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 06/13] KVM: s390: pv: refactor s390_reset_acc Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 07/13] KVM: s390: pv: usage counter instead of flag Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 08/13] KVM: s390: pv: add export before import Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 09/13] KVM: s390: pv: lazy destroy for reboot Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 10/13] KVM: s390: pv: extend lazy destroy to handle shutdown Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 11/13] KVM: s390: pv: module parameter to fence lazy destroy Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 12/13] KVM: s390: pv: add OOM notifier for " Claudio Imbrenda 2021-07-28 14:26 ` [PATCH v2 13/13] KVM: s390: pv: add support for UV feature bits Claudio Imbrenda 2021-07-29 9:52 ` Janosch Frank 2021-07-29 13:28 ` Claudio Imbrenda
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