From: Paolo Bonzini <pbonzini@redhat.com>
To: Christoffer Dall <christoffer.dall@linaro.org>
Cc: peter.maydell@linaro.org, Andrew Jones <drjones@redhat.com>,
ard.biesheuvel@linaro.org, marc.zyngier@arm.com,
catalin.marinas@arm.com, "Michael S. Tsirkin" <mst@redhat.com>,
qemu-devel@nongnu.org, agraf@suse.de,
j.fanguede@virtualopensystems.com,
Laszlo Ersek <lersek@redhat.com>,
kvmarm@lists.cs.columbia.edu, m.smarduch@samsung.com
Subject: Re: [Qemu-devel] [RFC/RFT PATCH v2 0/3] KVM: Introduce KVM_MEM_UNCACHED
Date: Thu, 14 May 2015 14:08:49 +0200 [thread overview]
Message-ID: <55549051.1090007@redhat.com> (raw)
In-Reply-To: <20150514120039.GU32765@cbox>
On 14/05/2015 14:00, Christoffer Dall wrote:
> So, getting back to my original question. Is the point then that UEFI
> must assume (from ACPI/DT) the cache-coherency properties of the PCI
> controller which exists in hardware on the system you're running on,
> even for the virtual PCI bus because that will be the semantics for
> assigned devices?
>
> And in that case, we have no way to distinguish between passthrough
> devices and virtual devices plugged into the virtual PCI bus?
Well, we could use the subsystem id. But it's a hack, and may cause
incompatibilities with some drivers. Michael, any ideas?
> What about the idea of having two virtual PCI buses on your system where
> one is always cache-coherent and uses for virtual devices, and the other
> is whatever the hardware is and used for passthrough devices?
I think that was rejected before.
Paolo
next prev parent reply other threads:[~2015-05-14 12:09 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-13 11:31 [Qemu-devel] [RFC/RFT PATCH v2 0/3] KVM: Introduce KVM_MEM_UNCACHED Andrew Jones
2015-05-13 11:31 ` [Qemu-devel] [RFC/RFT PATCH v2 1/3] arm/arm64: pageattr: add set_memory_nc Andrew Jones
2015-05-14 11:05 ` Christoffer Dall
2015-05-14 13:46 ` Andrew Jones
2015-05-15 14:51 ` Christoffer Dall
2015-05-18 15:53 ` Catalin Marinas
2015-05-19 10:03 ` Andrew Jones
2015-05-19 11:18 ` Catalin Marinas
2015-05-19 11:38 ` Andrew Jones
2015-05-20 10:01 ` Christoffer Dall
2015-05-20 11:24 ` Catalin Marinas
2015-05-23 1:08 ` Mario Smarduch
2015-05-25 17:11 ` Andrew Jones
2015-05-27 1:08 ` Mario Smarduch
2015-05-13 11:31 ` [Qemu-devel] [RFC/RFT PATCH v2 2/3] KVM: promote KVM_MEMSLOT_INCOHERENT to uapi Andrew Jones
2015-05-14 10:12 ` Paolo Bonzini
2015-05-14 10:34 ` Christoffer Dall
2015-05-13 11:31 ` [Qemu-devel] [RFC/RFT PATCH v2 3/3] arm/arm64: KVM: implement 'uncached' mem coherency Andrew Jones
2015-05-14 10:55 ` Christoffer Dall
2015-05-14 13:32 ` Andrew Jones
2015-05-15 15:02 ` Christoffer Dall
2015-05-15 17:04 ` Andrew Jones
2015-05-15 20:16 ` Jérémy Fanguède
2015-05-21 2:29 ` Mario Smarduch
2015-05-21 16:50 ` Andrew Jones
2015-05-14 10:30 ` [Qemu-devel] [RFC/RFT PATCH v2 0/3] KVM: Introduce KVM_MEM_UNCACHED Christoffer Dall
2015-05-14 11:09 ` Laszlo Ersek
2015-05-14 11:29 ` Christoffer Dall
2015-05-14 11:31 ` Paolo Bonzini
2015-05-14 11:36 ` Christoffer Dall
2015-05-14 11:38 ` Paolo Bonzini
2015-05-14 12:00 ` Christoffer Dall
2015-05-14 12:08 ` Paolo Bonzini [this message]
2015-05-14 12:24 ` Christoffer Dall
2015-05-14 12:28 ` Paolo Bonzini
2015-05-14 12:34 ` Christoffer Dall
2015-05-14 13:01 ` Laszlo Ersek
2015-05-14 12:38 ` Peter Maydell
2015-05-14 13:00 ` Andrew Jones
2015-05-14 13:32 ` Laszlo Ersek
2015-05-14 13:48 ` Michael S. Tsirkin
2015-05-14 14:19 ` Laszlo Ersek
2015-05-14 14:41 ` Michael S. Tsirkin
2015-05-15 9:00 ` Ard Biesheuvel
2015-05-14 10:31 ` Andrew Jones
2015-05-14 10:37 ` Peter Maydell
2015-05-14 13:03 ` Andrew Jones
2015-05-14 13:11 ` Peter Maydell
2015-05-14 13:33 ` Laszlo Ersek
2015-05-14 13:36 ` Andrew Jones
2015-05-15 15:09 ` Christoffer Dall
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