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From: Paolo Bonzini <pbonzini@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, gleb@redhat.com,
	mtosatti@redhat.com, Avi Kivity <avi.kivity@gmail.com>
Subject: Re: [PATCH v2 5/6] kvm: add PV MMIO
Date: Thu, 04 Apr 2013 16:56:11 +0200	[thread overview]
Message-ID: <515D948B.8080407@redhat.com> (raw)
In-Reply-To: <20130404131015.GF6467@redhat.com>

Il 04/04/2013 15:10, Michael S. Tsirkin ha scritto:
> > I would like Avi to comment on this, because I think this is not the
> > "memory-API approved" way of doing things.  You need KVM to define its
> > own AddressSpace, and make KVM's listener use
> > memory_region_to_address_space to figure out if it is for PV MMIO.
> > 
> > To handle accesses from TCG, the PV AddressSpace can simply have just an
> > alias to the actual MemoryRegion where the doorbell is.
> 
> This is not really different from other eventfd flags like datamatch.
> Separate address space is not appropriate here.
> This is regular memory space, KVM eventfd simply has a flag that says
> "guest is well behaved so please make eventfd go faster".

Having a separate address space would match what you do in the kernel
though.

I just don't like functions with a dozen arguments...  Can you just make
datamatch and pv a single flags argument, as is the case with the KVM API?

Paolo


WARNING: multiple messages have this Message-ID (diff)
From: Paolo Bonzini <pbonzini@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: gleb@redhat.com, mtosatti@redhat.com, qemu-devel@nongnu.org,
	kvm@vger.kernel.org, Avi Kivity <avi.kivity@gmail.com>
Subject: Re: [Qemu-devel] [PATCH v2 5/6] kvm: add PV MMIO
Date: Thu, 04 Apr 2013 16:56:11 +0200	[thread overview]
Message-ID: <515D948B.8080407@redhat.com> (raw)
In-Reply-To: <20130404131015.GF6467@redhat.com>

Il 04/04/2013 15:10, Michael S. Tsirkin ha scritto:
> > I would like Avi to comment on this, because I think this is not the
> > "memory-API approved" way of doing things.  You need KVM to define its
> > own AddressSpace, and make KVM's listener use
> > memory_region_to_address_space to figure out if it is for PV MMIO.
> > 
> > To handle accesses from TCG, the PV AddressSpace can simply have just an
> > alias to the actual MemoryRegion where the doorbell is.
> 
> This is not really different from other eventfd flags like datamatch.
> Separate address space is not appropriate here.
> This is regular memory space, KVM eventfd simply has a flag that says
> "guest is well behaved so please make eventfd go faster".

Having a separate address space would match what you do in the kernel
though.

I just don't like functions with a dozen arguments...  Can you just make
datamatch and pv a single flags argument, as is the case with the KVM API?

Paolo

  reply	other threads:[~2013-04-04 14:56 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-04 10:39 [PATCH v2 0/6] kvm: pci PORT IO MMIO and PV MMIO speed tests Michael S. Tsirkin
2013-04-04 10:39 ` [Qemu-devel] " Michael S. Tsirkin
2013-04-04 10:40 ` [PATCH v2 4/6] pci: add pci test device Michael S. Tsirkin
2013-04-04 10:40   ` [Qemu-devel] " Michael S. Tsirkin
2013-04-04 10:40 ` [PATCH v2 1/6] kvm: remove unused APIs Michael S. Tsirkin
2013-04-04 10:40   ` [Qemu-devel] " Michael S. Tsirkin
2013-04-04 10:40 ` [PATCH v2 2/6] kvm: support any size for pio eventfd Michael S. Tsirkin
2013-04-04 10:40   ` [Qemu-devel] " Michael S. Tsirkin
2013-04-04 10:40 ` [PATCH v2 3/6] kvm: support non datamatch ioeventfd Michael S. Tsirkin
2013-04-04 10:40   ` [Qemu-devel] " Michael S. Tsirkin
2013-04-04 10:40 ` [PATCH v2 6/6] pci-testdev: add pv mmio test Michael S. Tsirkin
2013-04-04 10:40   ` [Qemu-devel] " Michael S. Tsirkin
2013-04-04 10:40 ` [PATCH v2 5/6] kvm: add PV MMIO Michael S. Tsirkin
2013-04-04 10:40   ` [Qemu-devel] " Michael S. Tsirkin
2013-04-04 12:46   ` Paolo Bonzini
2013-04-04 12:46     ` [Qemu-devel] " Paolo Bonzini
2013-04-04 13:10     ` Michael S. Tsirkin
2013-04-04 13:10       ` [Qemu-devel] " Michael S. Tsirkin
2013-04-04 14:56       ` Paolo Bonzini [this message]
2013-04-04 14:56         ` Paolo Bonzini
2013-04-04 14:38         ` Michael S. Tsirkin
2013-04-04 14:38           ` [Qemu-devel] " Michael S. Tsirkin
2013-04-04 12:50   ` Peter Maydell
2013-04-04 12:50     ` Peter Maydell
2013-04-04 13:11     ` Michael S. Tsirkin
2013-04-04 13:11       ` Michael S. Tsirkin
2013-04-04 14:23       ` Peter Maydell
2013-04-04 14:23         ` Peter Maydell
2013-04-04 13:34         ` Michael S. Tsirkin
2013-04-04 13:34           ` Michael S. Tsirkin

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