From: Thomas Huth <thuth@redhat.com>
To: kvm-ppc@vger.kernel.org, qemu-ppc@nongnu.org, kvm@vger.kernel.org
Cc: Alex Williamson <alex.williamson@redhat.com>,
David Gibson <dgibson@redhat.com>,
Bharata B Rao <bharata@linux.vnet.ibm.com>
Subject: KVM memory slots limit on powerpc
Date: Fri, 4 Sep 2015 11:35:56 +0200 [thread overview]
Message-ID: <55E965FC.8080909@redhat.com> (raw)
Hi all,
now that we get memory hotplugging for the spapr machine on qemu-ppc,
too, it seems like we easily can hit the amount of KVM-internal memory
slots now ("#define KVM_USER_MEM_SLOTS 32" in
arch/powerpc/include/asm/kvm_host.h). For example, start
qemu-system-ppc64 with a couple of "-device secondary-vga" and "-m
4G,slots=32,maxmem=40G" and then try to hot-plug all 32 DIMMs ... and
you'll see that it aborts way earlier already.
The x86 code already increased the amount of KVM_USER_MEM_SLOTS to 509
already (+3 internal slots = 512) ... maybe we should now increase the
amount of slots on powerpc, too? Since we don't use internal slots on
POWER, would 512 be a good value? Or would less be sufficient, too?
Thomas
next reply other threads:[~2015-09-04 9:36 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-04 9:35 Thomas Huth [this message]
2015-09-04 9:59 ` KVM memory slots limit on powerpc Christian Borntraeger
2015-09-04 10:04 ` [Qemu-ppc] " Alexander Graf
2015-09-04 10:07 ` Christian Borntraeger
2015-09-04 10:28 ` Thomas Huth
2015-09-04 10:40 ` Benjamin Herrenschmidt
2015-09-04 14:22 ` Alex Williamson
2015-09-04 14:45 ` Thomas Huth
2015-09-07 14:31 ` Igor Mammedov
2015-09-08 6:05 ` Thomas Huth
2015-09-08 7:11 ` Christian Borntraeger
2015-09-08 9:22 ` Thomas Huth
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