Re: [PATCH v5] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 06/29/2010 03:28 PM, Roedel, Joerg wrote:

Do you mean, KVM_IOMMU_CACHE_COHERENCY should be set for the AMD IOMMU?
No, as far as I understand it the KVM_IOMMU_CACHE_COHERENCY flag is only
there because there are VT-d IOMMUs that does not support the snoop
force bit. In the AMD IOMMU case all hardware has this feature, the
IOMMU driver just has to use it for IOMMU-API page-tables too. This is
currently not the case. So this is only an IOMMU driver change.

The flag indicates to kvm that it doesn't need to worry about iommu cache coherency issues (for example, it can ignore wbinvd), so it needs to be set. THe following code

        if (iommu_domain_has_cap(kvm->arch.iommu_domain,
                                 IOMMU_CAP_CACHE_COHERENCY))
                kvm->arch.iommu_flags |= KVM_IOMMU_CACHE_COHERENCY;

does this, so it looks like you need to return true for iommu_domain_has_cap() after the change. So far only the intel iommu supports it.

--
error compiling committee.c: too many arguments to function

--
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


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux