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author | Paolo Bonzini <pbonzini@redhat.com> | 2016-03-03 14:35:44 +0100 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-03-03 14:36:07 +0100 |
commit | 61ec84f145ef2baac7ea3d6d5604c8f29c0068b7 (patch) | |
tree | b463675bf1656b0dcba411b1584e3cc99a4de7c7 /Documentation | |
parent | 433da86023f866820e9bcd7f0889d944005d311c (diff) | |
parent | 58ded4201ff028b15f6b317228faa5f154a0663f (diff) | |
download | op-kernel-dev-61ec84f145ef2baac7ea3d6d5604c8f29c0068b7.zip op-kernel-dev-61ec84f145ef2baac7ea3d6d5604c8f29c0068b7.tar.gz |
Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD
The highlights are:
* Enable VFIO device on PowerPC, from David Gibson
* Optimizations to speed up IPIs between vcpus in HV KVM,
from Suresh Warrier (who is also Suresh E. Warrier)
* In-kernel handling of IOMMU hypercalls, and support for dynamic DMA
windows (DDW), from Alexey Kardashevskiy.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 4a661e5..1104849 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3035,6 +3035,63 @@ Returns: 0 on success, -1 on error Queues an SMI on the thread's vcpu. +4.97 KVM_CAP_PPC_MULTITCE + +Capability: KVM_CAP_PPC_MULTITCE +Architectures: ppc +Type: vm + +This capability means the kernel is capable of handling hypercalls +H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user +space. This significantly accelerates DMA operations for PPC KVM guests. +User space should expect that its handlers for these hypercalls +are not going to be called if user space previously registered LIOBN +in KVM (via KVM_CREATE_SPAPR_TCE or similar calls). + +In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest, +user space might have to advertise it for the guest. For example, +IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is +present in the "ibm,hypertas-functions" device-tree property. + +The hypercalls mentioned above may or may not be processed successfully +in the kernel based fast path. If they can not be handled by the kernel, +they will get passed on to user space. So user space still has to have +an implementation for these despite the in kernel acceleration. + +This capability is always enabled. + +4.98 KVM_CREATE_SPAPR_TCE_64 + +Capability: KVM_CAP_SPAPR_TCE_64 +Architectures: powerpc +Type: vm ioctl +Parameters: struct kvm_create_spapr_tce_64 (in) +Returns: file descriptor for manipulating the created TCE table + +This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit +windows, described in 4.62 KVM_CREATE_SPAPR_TCE + +This capability uses extended struct in ioctl interface: + +/* for KVM_CAP_SPAPR_TCE_64 */ +struct kvm_create_spapr_tce_64 { + __u64 liobn; + __u32 page_shift; + __u32 flags; + __u64 offset; /* in pages */ + __u64 size; /* in pages */ +}; + +The aim of extension is to support an additional bigger DMA window with +a variable page size. +KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and +a bus offset of the corresponding DMA window, @size and @offset are numbers +of IOMMU pages. + +@flags are not used at the moment. + +The rest of functionality is identical to KVM_CREATE_SPAPR_TCE. + 5. The kvm_run structure ------------------------ |