2015-04-17 19:12+0200, Jan Kiszka: > 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. :) Ah, your patch should be sufficient on AMD ... (At least the documentation doesn't list other NPT switches.) The simple test case is 'wrmsr(0x277, 0x0707070707070707)' and RAM accesses in a bounded loop -- they aren't significantly slower? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
