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author | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-11-05 15:11:05 +1100 |
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committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-11-05 15:11:05 +1100 |
commit | 2633dfbcb4803a0e39c6364caf37f2b055ba83eb (patch) | |
tree | bb6f7e3115decd24f93ab99773741b8a563da6c2 /Documentation | |
parent | 457dc90b2aea757818bdfa8d20fddbb3389329fc (diff) | |
parent | 81e87e26796782e014fd1f2bb9cd8fb6ce4021a8 (diff) |
Merge remote-tracking branch 'kvm/linux-next'
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/virtual/kvm/00-INDEX | 24 | ||||
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 108 | ||||
-rw-r--r-- | Documentation/virtual/kvm/devices/vfio.txt | 22 | ||||
-rw-r--r-- | Documentation/virtual/kvm/locking.txt | 19 |
4 files changed, 164 insertions, 9 deletions
diff --git a/Documentation/virtual/kvm/00-INDEX b/Documentation/virtual/kvm/00-INDEX new file mode 100644 index 000000000000..641ec9220179 --- /dev/null +++ b/Documentation/virtual/kvm/00-INDEX @@ -0,0 +1,24 @@ +00-INDEX + - this file. +api.txt + - KVM userspace API. +cpuid.txt + - KVM-specific cpuid leaves (x86). +devices/ + - KVM_CAP_DEVICE_CTRL userspace API. +hypercalls.txt + - KVM hypercalls. +locking.txt + - notes on KVM locks. +mmu.txt + - the x86 kvm shadow mmu. +msr.txt + - KVM-specific MSRs (x86). +nested-vmx.txt + - notes on nested virtualization for Intel x86 processors. +ppc-pv.txt + - the paravirtualization interface on PowerPC. +review-checklist.txt + - review checklist for KVM patches. +timekeeping.txt + - timekeeping virtualization for x86-based architectures. diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 858aecf21db2..488964414f04 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1122,9 +1122,9 @@ struct kvm_cpuid2 { struct kvm_cpuid_entry2 entries[0]; }; -#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX 1 -#define KVM_CPUID_FLAG_STATEFUL_FUNC 2 -#define KVM_CPUID_FLAG_STATE_READ_NEXT 4 +#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) +#define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) +#define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) struct kvm_cpuid_entry2 { __u32 function; @@ -2304,7 +2304,31 @@ Possible features: Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only). -4.83 KVM_GET_REG_LIST +4.83 KVM_ARM_PREFERRED_TARGET + +Capability: basic +Architectures: arm, arm64 +Type: vm ioctl +Parameters: struct struct kvm_vcpu_init (out) +Returns: 0 on success; -1 on error +Errors: + ENODEV: no preferred target available for the host + +This queries KVM for preferred CPU target type which can be emulated +by KVM on underlying host. + +The ioctl returns struct kvm_vcpu_init instance containing information +about preferred CPU target type and recommended features for it. The +kvm_vcpu_init->features bitmap returned will have feature bits set if +the preferred target recommends setting these features, but this is +not mandatory. + +The information returned by this ioctl can be used to prepare an instance +of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in +in VCPU matching underlying host. + + +4.84 KVM_GET_REG_LIST Capability: basic Architectures: arm, arm64 @@ -2323,8 +2347,7 @@ struct kvm_reg_list { This ioctl returns the guest registers that are supported for the KVM_GET_ONE_REG/KVM_SET_ONE_REG calls. - -4.84 KVM_ARM_SET_DEVICE_ADDR +4.85 KVM_ARM_SET_DEVICE_ADDR Capability: KVM_CAP_ARM_SET_DEVICE_ADDR Architectures: arm, arm64 @@ -2362,7 +2385,7 @@ must be called after calling KVM_CREATE_IRQCHIP, but before calling KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the base addresses will return -EEXIST. -4.85 KVM_PPC_RTAS_DEFINE_TOKEN +4.86 KVM_PPC_RTAS_DEFINE_TOKEN Capability: KVM_CAP_PPC_RTAS Architectures: ppc @@ -2661,6 +2684,77 @@ and usually define the validity of a groups of registers. (e.g. one bit }; +4.81 KVM_GET_EMULATED_CPUID + +Capability: KVM_CAP_EXT_EMUL_CPUID +Architectures: x86 +Type: system ioctl +Parameters: struct kvm_cpuid2 (in/out) +Returns: 0 on success, -1 on error + +struct kvm_cpuid2 { + __u32 nent; + __u32 flags; + struct kvm_cpuid_entry2 entries[0]; +}; + +The member 'flags' is used for passing flags from userspace. + +#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) +#define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) +#define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) + +struct kvm_cpuid_entry2 { + __u32 function; + __u32 index; + __u32 flags; + __u32 eax; + __u32 ebx; + __u32 ecx; + __u32 edx; + __u32 padding[3]; +}; + +This ioctl returns x86 cpuid features which are emulated by +kvm.Userspace can use the information returned by this ioctl to query +which features are emulated by kvm instead of being present natively. + +Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2 +structure with the 'nent' field indicating the number of entries in +the variable-size array 'entries'. If the number of entries is too low +to describe the cpu capabilities, an error (E2BIG) is returned. If the +number is too high, the 'nent' field is adjusted and an error (ENOMEM) +is returned. If the number is just right, the 'nent' field is adjusted +to the number of valid entries in the 'entries' array, which is then +filled. + +The entries returned are the set CPUID bits of the respective features +which kvm emulates, as returned by the CPUID instruction, with unknown +or unsupported feature bits cleared. + +Features like x2apic, for example, may not be present in the host cpu +but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be +emulated efficiently and thus not included here. + +The fields in each entry are defined as follows: + + function: the eax value used to obtain the entry + index: the ecx value used to obtain the entry (for entries that are + affected by ecx) + flags: an OR of zero or more of the following: + KVM_CPUID_FLAG_SIGNIFCANT_INDEX: + if the index field is valid + KVM_CPUID_FLAG_STATEFUL_FUNC: + if cpuid for this function returns different values for successive + invocations; there will be several entries with the same function, + all with this flag set + KVM_CPUID_FLAG_STATE_READ_NEXT: + for KVM_CPUID_FLAG_STATEFUL_FUNC entries, set if this entry is + the first entry to be read by a cpu + eax, ebx, ecx, edx: the values returned by the cpuid instruction for + this function/index combination + + 6. Capabilities that can be enabled ----------------------------------- diff --git a/Documentation/virtual/kvm/devices/vfio.txt b/Documentation/virtual/kvm/devices/vfio.txt new file mode 100644 index 000000000000..ef51740c67ca --- /dev/null +++ b/Documentation/virtual/kvm/devices/vfio.txt @@ -0,0 +1,22 @@ +VFIO virtual device +=================== + +Device types supported: + KVM_DEV_TYPE_VFIO + +Only one VFIO instance may be created per VM. The created device +tracks VFIO groups in use by the VM and features of those groups +important to the correctness and acceleration of the VM. As groups +are enabled and disabled for use by the VM, KVM should be updated +about their presence. When registered with KVM, a reference to the +VFIO-group is held by KVM. + +Groups: + KVM_DEV_VFIO_GROUP + +KVM_DEV_VFIO_GROUP attributes: + KVM_DEV_VFIO_GROUP_ADD: Add a VFIO group to VFIO-KVM device tracking + KVM_DEV_VFIO_GROUP_DEL: Remove a VFIO group from VFIO-KVM device tracking + +For each, kvm_device_attr.addr points to an int32_t file descriptor +for the VFIO group. diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index 41b7ac9884b5..f8869410d40c 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -132,10 +132,14 @@ See the comments in spte_has_volatile_bits() and mmu_spte_update(). ------------ Name: kvm_lock -Type: raw_spinlock +Type: spinlock_t Arch: any Protects: - vm_list - - hardware virtualization enable/disable + +Name: kvm_count_lock +Type: raw_spinlock_t +Arch: any +Protects: - hardware virtualization enable/disable Comment: 'raw' because hardware enabling/disabling must be atomic /wrt migration. @@ -151,3 +155,14 @@ Type: spinlock_t Arch: any Protects: -shadow page/shadow tlb entry Comment: it is a spinlock since it is used in mmu notifier. + +Name: kvm->srcu +Type: srcu lock +Arch: any +Protects: - kvm->memslots + - kvm->buses +Comment: The srcu read lock must be held while accessing memslots (e.g. + when using gfn_to_* functions) and while accessing in-kernel + MMIO/PIO address->device structure mapping (kvm->buses). + The srcu index can be stored in kvm_vcpu->srcu_idx per vcpu + if it is needed by multiple functions. |