From: Paul Mackerras <paulus@samba.org>
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: kvm-ppc@vger.kernel.org, Linuxppc-dev <linuxppc-dev@ozlabs.org>,
Alexander Graf <agraf@suse.de>, KVM list <kvm@vger.kernel.org>,
Jimi Xenidis <jimix@pobox.com>
Subject: Re: [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode
Date: Wed, 1 Jun 2011 15:11:45 +1000 [thread overview]
Message-ID: <20110601051145.GB6773@brick.ozlabs.ibm.com> (raw)
In-Reply-To: <c71b71560e43813012b6f293230dc78e@kernel.crashing.org>
On Wed, Jun 01, 2011 at 12:34:43AM +0200, Segher Boessenkool wrote:
> There's a loop of 128 iterations of 3 insns.
>
> I'm not saying it is actually bad, just that that 50 is slightly off ;-)
That would be the TLB invalidation. On POWER7 we only need to do that
if the virtual cpu last ran on a different physical cpu, or if this
physical cpu last ran a different virtual cpu in the same partition.
So hopefully we don't have to do it very often.
The reason we have to do it in that case is to allow the optimization
where we use tlbiel for TLB invalidations if the guest claims that
the translation being invalidated was only ever used on this virtual
cpu. That means that we have to guard against stale TLB entries left
behind when a virtual cpu moves from one physical cpu to another.
Paul.
next prev parent reply other threads:[~2011-06-01 5:11 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-11 10:34 [PATCH 0/13] Hypervisor-mode KVM on POWER7 Paul Mackerras
2011-05-11 10:36 ` [PATCH 01/13] kvm/powerpc: Move fields between struct kvm_vcpu_arch and kvmppc_vcpu_book3s Paul Mackerras
2011-05-11 10:38 ` [PATCH 02/13] kvm/powerpc: Fix kvmppc_core_pending_dec Paul Mackerras
2011-05-11 10:39 ` [PATCH 03/13] kvm/powerpc: Fix the build for 32-bit Book 3S (classic) processors Paul Mackerras
2011-05-12 9:33 ` Alexander Graf
2011-05-12 11:15 ` Paul Mackerras
2011-05-12 11:16 ` Benjamin Herrenschmidt
2011-05-12 11:57 ` Alexander Graf
2011-05-11 10:40 ` [PATCH 04/13] kvm/powerpc: Split out code from book3s.c into book3s_pr.c Paul Mackerras
2011-05-11 10:41 ` [PATCH 05/13] powerpc, kvm: Rework KVM checks in first-level interrupt handlers Paul Mackerras
2011-05-11 10:42 ` [PATCH 06/13] kvm/powerpc: Deliver program interrupts right away instead of queueing them Paul Mackerras
2011-05-11 10:42 ` [PATCH 07/13] kvm/powerpc: Pass init/destroy vm and prepare/commit memory region ops down Paul Mackerras
2011-05-11 10:43 ` [PATCH 08/13] kvm/powerpc: Move guest enter/exit down into subarch-specific code Paul Mackerras
2011-05-17 18:05 ` Marcelo Tosatti
2011-05-17 18:10 ` Marcelo Tosatti
2011-05-11 10:44 ` [PATCH 09/13] powerpc: Set up LPCR for running guest partitions Paul Mackerras
2011-05-11 10:44 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode Paul Mackerras
2011-05-12 9:07 ` Avi Kivity
2011-05-16 1:07 ` Paul Mackerras
2011-05-15 21:58 ` Alexander Graf
2011-05-16 5:58 ` Paul Mackerras
2011-05-17 10:17 ` Alexander Graf
2011-05-27 10:33 ` Paul Mackerras
2011-05-27 10:43 ` Alexander Graf
2011-05-27 20:59 ` Segher Boessenkool
2011-05-27 23:19 ` Alexander Graf
2011-05-28 1:07 ` Segher Boessenkool
2011-05-31 20:26 ` Jimi Xenidis
2011-05-31 22:34 ` Segher Boessenkool
2011-06-01 5:11 ` Paul Mackerras [this message]
2011-05-11 10:45 ` [PATCH 11/13] kvm/powerpc: Handle some PAPR hcalls in the kernel Paul Mackerras
2011-05-17 7:54 ` Alexander Graf
2011-05-17 10:28 ` Paul Mackerras
2011-05-11 10:46 ` [PATCH 12/13] kvm/powerpc: Accelerate H_PUT_TCE by implementing it in real mode Paul Mackerras
2011-05-17 8:01 ` Alexander Graf
2011-05-17 9:11 ` Benjamin Herrenschmidt
2011-05-17 9:31 ` Alexander Graf
2011-05-17 9:35 ` Benjamin Herrenschmidt
2011-05-17 9:39 ` Alexander Graf
2011-05-11 10:46 ` [PATCH 13/13] kvm/powerpc: Allow book3s_hv guests to use SMT processor modes Paul Mackerras
2011-05-11 13:44 ` Christoph Hellwig
2011-05-11 21:17 ` Paul Mackerras
2011-05-17 8:21 ` Alexander Graf
2011-05-17 10:44 ` Paul Mackerras
2011-05-17 11:36 ` Alexander Graf
2011-05-19 6:06 ` Paul Mackerras
2011-05-17 9:46 ` [PATCH 0/13] Hypervisor-mode KVM on POWER7 Alexander Graf
2011-05-17 11:15 ` Paul Mackerras
2011-05-17 11:38 ` Alexander Graf
2011-05-17 11:42 ` Avi Kivity
2011-05-19 5:22 ` Paul Mackerras
2011-05-19 6:01 ` Alexander Graf
2011-05-21 16:41 ` Alexander Graf
2011-05-21 17:00 ` Alexander Graf
2011-05-21 18:15 ` Alexander Graf
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