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From: catalin.marinas@arm•com (Catalin Marinas)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM64: KVM: Fix coherent_icache_guest_page() for host with external L3-cache.
Date: Thu, 29 Aug 2013 13:53:37 +0100	[thread overview]
Message-ID: <20130829125337.GG13704@arm.com> (raw)
In-Reply-To: <CAAhSdy0NgSchR1p_HJTUMMV2h7f7beFMnN3Md4xEp=EGRiXVMg@mail.gmail.com>

On Thu, Aug 29, 2013 at 01:31:43PM +0100, Anup Patel wrote:
> On Thu, Aug 29, 2013 at 4:22 PM, Catalin Marinas
> <catalin.marinas@arm•com> wrote:
> > On Fri, Aug 16, 2013 at 07:57:55AM +0100, Anup Patel wrote:
> >> The approach of flushing d-cache by set/way upon first run of VCPU will
> >> not work because for set/way operations ARM ARM says: "For set/way
> >> operations, and for All (entire cache) operations, the point is defined to be
> >> to the next level of caching". In other words, set/way operations work upto
> >> point of unification.
> >
> > I don't understand where you got the idea that set/way operations work
> > up to the point of unification. This is incorrect, the set/way
> > operations work on the level of cache specified by bits 3:1 in the
> > register passed to the DC CISW instruction. For your L3 cache, those
> > bits would be 2 (and __flush_dcache_all() implementation does this
> > dynamically).
> 
> The L3-cache is not visible to CPU. It is totally independent and transparent
> to CPU.

OK. But you say that operations like DC CIVAC actually flush the L3? So
I don't see it as completely transparent to the CPU.

Do you have any configuration bits which would make the L3 completely
transparent like always caching even when accesses are non-cacheable and
DC ops to PoC ignoring it?

Now, back to the idea of outer_cache framework for arm64. Does your CPU
have separate instructions for flushing this L3 cache?

-- 
Catalin

  reply	other threads:[~2013-08-29 12:53 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-14 11:47 [PATCH] ARM64: KVM: Fix coherent_icache_guest_page() for host with external L3-cache Pranavkumar Sawargaonkar
2013-08-14 12:04 ` Marc Zyngier
2013-08-14 14:22   ` Anup Patel
2013-08-14 15:06     ` Alexander Graf
2013-08-14 15:34       ` Marc Zyngier
2013-08-14 15:41         ` Peter Maydell
2013-08-14 15:57           ` Marc Zyngier
2013-08-14 16:36             ` Anup Patel
2013-08-14 15:23     ` Marc Zyngier
2013-08-14 15:35       ` Peter Maydell
2013-08-14 15:49         ` Marc Zyngier
2013-08-14 17:34           ` Christoffer Dall
2013-08-15  4:44             ` Marc Zyngier
2013-08-15 16:58               ` Christoffer Dall
2013-08-14 15:36       ` Anup Patel
2013-08-15  4:52     ` Marc Zyngier
2013-08-15  6:26       ` Anup Patel
2013-08-15  8:31         ` Marc Zyngier
2013-08-15 13:31           ` Anup Patel
2013-08-15 14:47             ` Marc Zyngier
2013-08-15 15:13               ` Anup Patel
2013-08-15 15:37                 ` Marc Zyngier
2013-08-15 15:45                   ` Anup Patel
2013-08-15 16:53                   ` Christoffer Dall
2013-08-16  5:02                     ` Anup Patel
2013-08-16  6:57                       ` Anup Patel
2013-08-16 17:19                         ` Christoffer Dall
2013-08-16 17:42                           ` Anup Patel
2013-08-16 17:50                             ` Christoffer Dall
2013-08-16 18:06                               ` Christoffer Dall
2013-08-16 18:20                                 ` Anup Patel
2013-08-16 18:11                               ` Anup Patel
2013-08-16 18:20                                 ` Christoffer Dall
2013-08-30  9:52                                 ` Catalin Marinas
2013-08-30 10:44                                   ` Anup Patel
2013-08-30 13:02                                     ` Catalin Marinas
2013-08-30 13:21                                     ` Marc Zyngier
2013-08-30 14:04                                       ` Catalin Marinas
2013-08-30 14:22                                         ` Marc Zyngier
2013-08-30 14:30                                           ` Will Deacon
2013-08-30 14:52                                             ` Anup Patel
2013-08-30 15:12                                             ` Marc Zyngier
2013-08-29 10:52                         ` Catalin Marinas
2013-08-29 12:31                           ` Anup Patel
2013-08-29 12:53                             ` Catalin Marinas [this message]
2013-08-29 16:02                               ` Anup Patel
2013-08-30  9:44                                 ` Catalin Marinas
2013-08-30 10:36                                   ` Anup Patel
2013-08-30 12:52                                     ` Catalin Marinas
2013-08-16 17:14                       ` Christoffer Dall
     [not found]                         ` <CALrVBkvEP1Q0mKpv8ViOTLRvW2ks18MQXgmurSBHn+aJcz+=gw@mail.gmail.com>
2013-08-16 17:28                           ` Christoffer Dall
2013-08-16 17:42                             ` Christoffer Dall
2013-08-15  8:39       ` Pranavkumar Sawargaonkar
2013-08-15 15:42         ` Marc Zyngier
2013-08-14 14:23 ` Sudeep KarkadaNagesha
2013-08-14 14:35   ` Anup Patel
2013-08-14 17:37 ` Christoffer Dall
  -- strict thread matches above, loose matches on Subject: below --
2013-08-14 11:45 Pranavkumar Sawargaonkar

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