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Re: [Qemu-devel] [PATCH 20/40] pci: use memory core for iommu support
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [PATCH 20/40] pci: use memory core for iommu support |
Date: |
Sat, 11 May 2013 09:07:03 +0100 |
On 11 May 2013 06:09, liu ping fan <address@hidden> wrote:
> On Wed, May 8, 2013 at 2:30 AM, Peter Maydell <address@hidden> wrote:
>> Also, technically speaking get_system_memory() is never the
>> right answer, though in practice it's good enough for our
>> purposes. (returning get_system_memory() would allow a bus
>> master DMA device to access back into the PCI bus by
>> DMAing to the address in system memory where the PCI host
>> controller is mapped, which I'm guessing is not possible
>> on real hardware.)
>>
> I think although it is rare case, but PCI device can fetch another's
> data on its pci-ram, expecially pci-spec does not forbid it.
Yes, certainly, but this happens because the other pci device
is present in the PCI address space, not because PCI device
A talks to the host controller's CPU-facing interface and
accesses PCI device B that way...
-- PMM
- Re: [Qemu-devel] [PATCH 11/40] memory: add address_space_valid, (continued)
[Qemu-devel] [PATCH 13/40] memory: Introduce address_space_lookup_region, Paolo Bonzini, 2013/05/07
[Qemu-devel] [PATCH 14/40] memory: iommu support, Paolo Bonzini, 2013/05/07
[Qemu-devel] [PATCH 12/40] memory: add address_space_translate, Paolo Bonzini, 2013/05/07
[Qemu-devel] [PATCH 20/40] pci: use memory core for iommu support, Paolo Bonzini, 2013/05/07
Re: [Qemu-devel] [PATCH 20/40] pci: use memory core for iommu support, Alexey Kardashevskiy, 2013/05/10
Re: [Qemu-devel] [PATCH 20/40] pci: use memory core for iommu support, Paolo Bonzini, 2013/05/10
[Qemu-devel] [PATCH 19/40] dma: eliminate old-style IOMMU support, Paolo Bonzini, 2013/05/07
[Qemu-devel] [PATCH 21/40] spapr_vio: take care of creating our own AddressSpace/DMAContext, Paolo Bonzini, 2013/05/07
[Qemu-devel] [PATCH 26/40] memory: add ref/unref calls, Paolo Bonzini, 2013/05/07
[Qemu-devel] [PATCH 28/40] sysbus: set owner for MMIO regions, Paolo Bonzini, 2013/05/07
[Qemu-devel] [PATCH 27/40] pci: set owner for BARs, Paolo Bonzini, 2013/05/07
[Qemu-devel] [PATCH 29/40] acpi: add memory_region_set_owner calls, Paolo Bonzini, 2013/05/07