Re: KVM: How does is PAT emulation supposed to work?

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2015-04-17 18:43, Radim Krčmář wrote:
> 2015-04-13 07:16+0200, Jan Kiszka:
>> PS: If someone has a good idea for a simple test case on machines
>> without IOMMU (like my current boxes), thus without a chance to use
>> device pass-through to stress guest PAT settings, I would be all ears.
> 
> Not a good one:  KVM sets VMX_EPT_IPAT_BIT for RAM unless
> kvm_arch_has_noncoherent_dma().  You can comment the line in
> vmx_get_mt_mask(), or call kvm_arch_register_noncoherent_dma(),
> for guest PAT to work on normal memory.

That's for VMX (where I do have IOMMUs), but I would need something for
AMD. :)

Jan

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