diff options
Diffstat (limited to 'Documentation/virtual')
| -rw-r--r-- | Documentation/virtual/kvm/00-INDEX | 26 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 316 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/cpuid.txt | 11 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/arm-vgic.txt | 73 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/s390_flic.txt | 91 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/vfio.txt | 22 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/devices/vm.txt | 26 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/hypercalls.txt | 17 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/locking.txt | 23 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/mmu.txt | 91 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/ppc-pv.txt | 16 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/s390-diag.txt | 82 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/timekeeping.txt | 2 | ||||
| -rw-r--r-- | Documentation/virtual/uml/UserModeLinux-HOWTO.txt | 4 |
14 files changed, 737 insertions, 63 deletions
diff --git a/Documentation/virtual/kvm/00-INDEX b/Documentation/virtual/kvm/00-INDEX new file mode 100644 index 00000000000..fee9f2bf9c6 --- /dev/null +++ b/Documentation/virtual/kvm/00-INDEX @@ -0,0 +1,26 @@ +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. +s390-diag.txt + - Diagnose hypercall description (for IBM S/390) +timekeeping.txt + - timekeeping virtualization for x86-based architectures. diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 5f91eda9164..0fe36497642 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -53,7 +53,7 @@ incompatible change are allowed. However, there is an extension facility that allows backward-compatible extensions to the API to be queried and used. -The extension mechanism is not based on on the Linux version number. +The extension mechanism is not based on the Linux version number. Instead, kvm defines extension identifiers and a facility to query whether a particular extension identifier is available. If it is, a set of ioctls is available for application use. @@ -280,7 +280,7 @@ kvm_run' (see below). 4.11 KVM_GET_REGS Capability: basic -Architectures: all except ARM +Architectures: all except ARM, arm64 Type: vcpu ioctl Parameters: struct kvm_regs (out) Returns: 0 on success, -1 on error @@ -301,7 +301,7 @@ struct kvm_regs { 4.12 KVM_SET_REGS Capability: basic -Architectures: all except ARM +Architectures: all except ARM, arm64 Type: vcpu ioctl Parameters: struct kvm_regs (in) Returns: 0 on success, -1 on error @@ -586,8 +586,8 @@ struct kvm_fpu { 4.24 KVM_CREATE_IRQCHIP -Capability: KVM_CAP_IRQCHIP -Architectures: x86, ia64, ARM +Capability: KVM_CAP_IRQCHIP, KVM_CAP_S390_IRQCHIP (s390) +Architectures: x86, ia64, ARM, arm64, s390 Type: vm ioctl Parameters: none Returns: 0 on success, -1 on error @@ -595,14 +595,17 @@ Returns: 0 on success, -1 on error Creates an interrupt controller model in the kernel. On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up future vcpus to have a local APIC. IRQ routing for GSIs 0-15 is set to both PIC and IOAPIC; GSI 16-23 -only go to the IOAPIC. On ia64, a IOSAPIC is created. On ARM, a GIC is -created. +only go to the IOAPIC. On ia64, a IOSAPIC is created. On ARM/arm64, a GIC is +created. On s390, a dummy irq routing table is created. + +Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled +before KVM_CREATE_IRQCHIP can be used. 4.25 KVM_IRQ_LINE Capability: KVM_CAP_IRQCHIP -Architectures: x86, ia64, arm +Architectures: x86, ia64, arm, arm64 Type: vm ioctl Parameters: struct kvm_irq_level Returns: 0 on success, -1 on error @@ -612,9 +615,24 @@ On some architectures it is required that an interrupt controller model has been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered interrupts require the level to be set to 1 and then back to 0. -ARM can signal an interrupt either at the CPU level, or at the in-kernel irqchip -(GIC), and for in-kernel irqchip can tell the GIC to use PPIs designated for -specific cpus. The irq field is interpreted like this: +On real hardware, interrupt pins can be active-low or active-high. This +does not matter for the level field of struct kvm_irq_level: 1 always +means active (asserted), 0 means inactive (deasserted). + +x86 allows the operating system to program the interrupt polarity +(active-low/active-high) for level-triggered interrupts, and KVM used +to consider the polarity. However, due to bitrot in the handling of +active-low interrupts, the above convention is now valid on x86 too. +This is signaled by KVM_CAP_X86_IOAPIC_POLARITY_IGNORED. Userspace +should not present interrupts to the guest as active-low unless this +capability is present (or unless it is not using the in-kernel irqchip, +of course). + + +ARM/arm64 can signal an interrupt either at the CPU level, or at the +in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to +use PPIs designated for specific cpus. The irq field is interpreted +like this: bits: | 31 ... 24 | 23 ... 16 | 15 ... 0 | field: | irq_type | vcpu_index | irq_id | @@ -627,7 +645,7 @@ The irq_type field has the following values: (The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs) -In both cases, level is used to raise/lower the line. +In both cases, level is used to assert/deassert the line. struct kvm_irq_level { union { @@ -917,9 +935,9 @@ documentation when it pops into existence). 4.37 KVM_ENABLE_CAP -Capability: KVM_CAP_ENABLE_CAP +Capability: KVM_CAP_ENABLE_CAP, KVM_CAP_ENABLE_CAP_VM Architectures: ppc, s390 -Type: vcpu ioctl +Type: vcpu ioctl, vm ioctl (with KVM_CAP_ENABLE_CAP_VM) Parameters: struct kvm_enable_cap (in) Returns: 0 on success; -1 on error @@ -950,6 +968,8 @@ function properly, this is the place to put them. __u8 pad[64]; }; +The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl +for vm-wide capabilities. 4.38 KVM_GET_MP_STATE @@ -1121,9 +1141,9 @@ 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; @@ -1319,7 +1339,7 @@ KVM_ASSIGN_DEV_IRQ. Partial deassignment of host or guest IRQ is allowed. 4.52 KVM_SET_GSI_ROUTING Capability: KVM_CAP_IRQ_ROUTING -Architectures: x86 ia64 +Architectures: x86 ia64 s390 Type: vm ioctl Parameters: struct kvm_irq_routing (in) Returns: 0 on success, -1 on error @@ -1342,6 +1362,7 @@ struct kvm_irq_routing_entry { union { struct kvm_irq_routing_irqchip irqchip; struct kvm_irq_routing_msi msi; + struct kvm_irq_routing_s390_adapter adapter; __u32 pad[8]; } u; }; @@ -1349,6 +1370,7 @@ struct kvm_irq_routing_entry { /* gsi routing entry types */ #define KVM_IRQ_ROUTING_IRQCHIP 1 #define KVM_IRQ_ROUTING_MSI 2 +#define KVM_IRQ_ROUTING_S390_ADAPTER 3 No flags are specified so far, the corresponding field must be set to zero. @@ -1364,6 +1386,14 @@ struct kvm_irq_routing_msi { __u32 pad; }; +struct kvm_irq_routing_s390_adapter { + __u64 ind_addr; + __u64 summary_addr; + __u64 ind_offset; + __u32 summary_offset; + __u32 adapter_id; +}; + 4.53 KVM_ASSIGN_SET_MSIX_NR @@ -1461,7 +1491,7 @@ struct kvm_lapic_state { char regs[KVM_APIC_REG_SIZE]; }; -Copies the input argument into the the Local APIC registers. The data format +Copies the input argument into the Local APIC registers. The data format and layout are the same as documented in the architecture manual. @@ -1683,7 +1713,7 @@ The parameter is defined like this: This ioctl maps the memory at "user_addr" with the length "length" to the vcpu's address space starting at "vcpu_addr". All parameters need to -be alligned by 1 megabyte. +be aligned by 1 megabyte. 4.66 KVM_S390_UCAS_UNMAP @@ -1703,7 +1733,7 @@ The parameter is defined like this: This ioctl unmaps the memory in the vcpu's address space starting at "vcpu_addr" with the length "length". The field "user_addr" is ignored. -All parameters need to be alligned by 1 megabyte. +All parameters need to be aligned by 1 megabyte. 4.67 KVM_S390_VCPU_FAULT @@ -1764,6 +1794,11 @@ registers, find a list below: PPC | KVM_REG_PPC_MMCR0 | 64 PPC | KVM_REG_PPC_MMCR1 | 64 PPC | KVM_REG_PPC_MMCRA | 64 + PPC | KVM_REG_PPC_MMCR2 | 64 + PPC | KVM_REG_PPC_MMCRS | 64 + PPC | KVM_REG_PPC_SIAR | 64 + PPC | KVM_REG_PPC_SDAR | 64 + PPC | KVM_REG_PPC_SIER | 64 PPC | KVM_REG_PPC_PMC1 | 32 PPC | KVM_REG_PPC_PMC2 | 32 PPC | KVM_REG_PPC_PMC3 | 32 @@ -1809,6 +1844,52 @@ registers, find a list below: PPC | KVM_REG_PPC_TLB3PS | 32 PPC | KVM_REG_PPC_EPTCFG | 32 PPC | KVM_REG_PPC_ICP_STATE | 64 + PPC | KVM_REG_PPC_TB_OFFSET | 64 + PPC | KVM_REG_PPC_SPMC1 | 32 + PPC | KVM_REG_PPC_SPMC2 | 32 + PPC | KVM_REG_PPC_IAMR | 64 + PPC | KVM_REG_PPC_TFHAR | 64 + PPC | KVM_REG_PPC_TFIAR | 64 + PPC | KVM_REG_PPC_TEXASR | 64 + PPC | KVM_REG_PPC_FSCR | 64 + PPC | KVM_REG_PPC_PSPB | 32 + PPC | KVM_REG_PPC_EBBHR | 64 + PPC | KVM_REG_PPC_EBBRR | 64 + PPC | KVM_REG_PPC_BESCR | 64 + PPC | KVM_REG_PPC_TAR | 64 + PPC | KVM_REG_PPC_DPDES | 64 + PPC | KVM_REG_PPC_DAWR | 64 + PPC | KVM_REG_PPC_DAWRX | 64 + PPC | KVM_REG_PPC_CIABR | 64 + PPC | KVM_REG_PPC_IC | 64 + PPC | KVM_REG_PPC_VTB | 64 + PPC | KVM_REG_PPC_CSIGR | 64 + PPC | KVM_REG_PPC_TACR | 64 + PPC | KVM_REG_PPC_TCSCR | 64 + PPC | KVM_REG_PPC_PID | 64 + PPC | KVM_REG_PPC_ACOP | 64 + PPC | KVM_REG_PPC_VRSAVE | 32 + PPC | KVM_REG_PPC_LPCR | 64 + PPC | KVM_REG_PPC_PPR | 64 + PPC | KVM_REG_PPC_ARCH_COMPAT 32 + PPC | KVM_REG_PPC_DABRX | 32 + PPC | KVM_REG_PPC_WORT | 64 + PPC | KVM_REG_PPC_TM_GPR0 | 64 + ... + PPC | KVM_REG_PPC_TM_GPR31 | 64 + PPC | KVM_REG_PPC_TM_VSR0 | 128 + ... + PPC | KVM_REG_PPC_TM_VSR63 | 128 + PPC | KVM_REG_PPC_TM_CR | 64 + PPC | KVM_REG_PPC_TM_LR | 64 + PPC | KVM_REG_PPC_TM_CTR | 64 + PPC | KVM_REG_PPC_TM_FPSCR | 64 + PPC | KVM_REG_PPC_TM_AMR | 64 + PPC | KVM_REG_PPC_TM_PPR | 64 + PPC | KVM_REG_PPC_TM_VRSAVE | 64 + PPC | KVM_REG_PPC_TM_VSCR | 32 + PPC | KVM_REG_PPC_TM_DSCR | 64 + PPC | KVM_REG_PPC_TM_TAR | 64 ARM registers are mapped using the lower 32 bits. The upper 16 of that is the register group type, or coprocessor number: @@ -1831,6 +1912,22 @@ ARM 32-bit VFP control registers have the following id bit patterns: ARM 64-bit FP registers have the following id bit patterns: 0x4030 0000 0012 0 <regno:12> + +arm64 registers are mapped using the lower 32 bits. The upper 16 of +that is the register group type, or coprocessor number: + +arm64 core/FP-SIMD registers have the following id bit patterns. Note +that the size of the access is variable, as the kvm_regs structure +contains elements ranging from 32 to 128 bits. The index is a 32bit +value in the kvm_regs structure seen as a 32bit array. + 0x60x0 0000 0010 <index into the kvm_regs struct:16> + +arm64 CCSIDR registers are demultiplexed by CSSELR value: + 0x6020 0000 0011 00 <csselr:8> + +arm64 system registers have the following id bit patterns: + 0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3> + 4.69 KVM_GET_ONE_REG Capability: KVM_CAP_ONE_REG @@ -1972,10 +2069,10 @@ Returns: 0 on success, -1 on error This populates and returns a structure describing the features of the "Server" class MMU emulation supported by KVM. -This can in turn be used by userspace to generate the appropariate +This can in turn be used by userspace to generate the appropriate device-tree properties for the guest operating system. -The structure contains some global informations, followed by an +The structure contains some global information, followed by an array of supported segment page sizes: struct kvm_ppc_smmu_info { @@ -2019,7 +2116,7 @@ be OR'ed into the "vsid" argument of the slbmte instruction. The "enc" array is a list which for each of those segment base page size provides the list of supported actual page sizes (which can be only larger or equal to the base page size), along with the -corresponding encoding in the hash PTE. Similarily, the array is +corresponding encoding in the hash PTE. Similarly, the array is 8 entries sorted by increasing sizes and an entry with a "0" shift is an empty entry and a terminator: @@ -2035,7 +2132,7 @@ into the hash PTE second double word). 4.75 KVM_IRQFD Capability: KVM_CAP_IRQFD -Architectures: x86 +Architectures: x86 s390 Type: vm ioctl Parameters: struct kvm_irqfd (in) Returns: 0 on success, -1 on error @@ -2043,7 +2140,7 @@ Returns: 0 on success, -1 on error Allows setting an eventfd to directly trigger a guest interrupt. kvm_irqfd.fd specifies the file descriptor to use as the eventfd and kvm_irqfd.gsi specifies the irqchip pin toggled by this event. When -an event is tiggered on the eventfd, an interrupt is injected into +an event is triggered on the eventfd, an interrupt is injected into the guest using the specified gsi pin. The irqfd is removed using the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd and kvm_irqfd.gsi. @@ -2054,7 +2151,7 @@ interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an additional eventfd in the kvm_irqfd.resamplefd field. When operating in resample mode, posting of an interrupt through kvm_irq.fd asserts the specified gsi in the irqchip. When the irqchip is resampled, such -as from an EOI, the gsi is de-asserted and the user is notifed via +as from an EOI, the gsi is de-asserted and the user is notified via kvm_irqfd.resamplefd. It is the user's responsibility to re-queue the interrupt if the device making use of it still requires service. Note that closing the resamplefd is not sufficient to disable the @@ -2120,6 +2217,8 @@ KVM_S390_SIGP_STOP (vcpu) - sigp restart KVM_S390_PROGRAM_INT (vcpu) - program check; code in parm KVM_S390_SIGP_SET_PREFIX (vcpu) - sigp set prefix; prefix address in parm KVM_S390_RESTART (vcpu) - restart +KVM_S390_INT_CLOCK_COMP (vcpu) - clock comparator interrupt +KVM_S390_INT_CPU_TIMER (vcpu) - CPU timer interrupt KVM_S390_INT_VIRTIO (vm) - virtio external interrupt; external interrupt parameters in parm and parm64 KVM_S390_INT_SERVICE (vm) - sclp external interrupt; sclp parameter in parm @@ -2223,8 +2322,8 @@ struct kvm_create_device { 4.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR -Capability: KVM_CAP_DEVICE_CTRL -Type: device ioctl +Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device +Type: device ioctl, vm ioctl Parameters: struct kvm_device_attr Returns: 0 on success, -1 on error Errors: @@ -2249,8 +2348,8 @@ struct kvm_device_attr { 4.81 KVM_HAS_DEVICE_ATTR -Capability: KVM_CAP_DEVICE_CTRL -Type: device ioctl +Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device +Type: device ioctl, vm ioctl Parameters: struct kvm_device_attr Returns: 0 on success, -1 on error Errors: @@ -2261,12 +2360,12 @@ return indicates the attribute is implemented. It does not necessarily indicate that the attribute can be read or written in the device's current state. "addr" is ignored. -4.77 KVM_ARM_VCPU_INIT +4.82 KVM_ARM_VCPU_INIT Capability: basic -Architectures: arm +Architectures: arm, arm64 Type: vcpu ioctl -Parameters: struct struct kvm_vcpu_init (in) +Parameters: struct kvm_vcpu_init (in) Returns: 0 on success; -1 on error Errors: EINVAL: the target is unknown, or the combination of features is invalid. @@ -2283,12 +2382,40 @@ should be created before this ioctl is invoked. Possible features: - KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state. Depends on KVM_CAP_ARM_PSCI. + - KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode. + Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only). + - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 for the CPU. + Depends on KVM_CAP_ARM_PSCI_0_2. -4.78 KVM_GET_REG_LIST +4.83 KVM_ARM_PREFERRED_TARGET Capability: basic -Architectures: arm +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 Type: vcpu ioctl Parameters: struct kvm_reg_list (in/out) Returns: 0 on success; -1 on error @@ -2305,10 +2432,10 @@ This ioctl returns the guest registers that are supported for the KVM_GET_ONE_REG/KVM_SET_ONE_REG calls. -4.80 KVM_ARM_SET_DEVICE_ADDR +4.85 KVM_ARM_SET_DEVICE_ADDR (deprecated) Capability: KVM_CAP_ARM_SET_DEVICE_ADDR -Architectures: arm +Architectures: arm, arm64 Type: vm ioctl Parameters: struct kvm_arm_device_address (in) Returns: 0 on success, -1 on error @@ -2329,20 +2456,25 @@ can access emulated or directly exposed devices, which the host kernel needs to know about. The id field is an architecture specific identifier for a specific device. -ARM divides the id field into two parts, a device id and an address type id -specific to the individual device. +ARM/arm64 divides the id field into two parts, a device id and an +address type id specific to the individual device. bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 | field: | 0x00000000 | device id | addr type id | -ARM currently only require this when using the in-kernel GIC support for the -hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 as the device id. When -setting the base address for the guest's mapping of the VGIC virtual CPU -and distributor interface, the ioctl 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. +ARM/arm64 currently only require this when using the in-kernel GIC +support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 +as the device id. When setting the base address for the guest's +mapping of the VGIC virtual CPU and distributor interface, the ioctl +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. + +Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API +should be used instead. + -4.82 KVM_PPC_RTAS_DEFINE_TOKEN +4.86 KVM_PPC_RTAS_DEFINE_TOKEN Capability: KVM_CAP_PPC_RTAS Architectures: ppc @@ -2473,6 +2605,10 @@ executed a memory-mapped I/O instruction which could not be satisfied by kvm. The 'data' member contains the written data if 'is_write' is true, and should be filled by application code otherwise. +The 'data' member contains, in its first 'len' bytes, the value as it would +appear if the VCPU performed a load or store of the appropriate width directly +to the byte array. + NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_DCR, KVM_EXIT_PAPR and KVM_EXIT_EPR the corresponding operations are complete (and guest state is consistent) only after userspace @@ -2612,6 +2748,21 @@ It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an external interrupt has just been delivered into the guest. User space should put the acknowledged interrupt vector into the 'epr' field. + /* KVM_EXIT_SYSTEM_EVENT */ + struct { +#define KVM_SYSTEM_EVENT_SHUTDOWN 1 +#define KVM_SYSTEM_EVENT_RESET 2 + __u32 type; + __u64 flags; + } system_event; + +If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered +a system-level event using some architecture specific mechanism (hypercall +or some special instruction). In case of ARM/ARM64, this is triggered using +HVC instruction based PSCI call from the vcpu. The 'type' field describes +the system-level event type. The 'flags' field describes architecture +specific flags for the system-level event. + /* Fix the size of the union. */ char padding[256]; }; @@ -2641,6 +2792,77 @@ 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/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt index 83afe65d496..3c65feb8301 100644 --- a/Documentation/virtual/kvm/cpuid.txt +++ b/Documentation/virtual/kvm/cpuid.txt @@ -43,6 +43,17 @@ KVM_FEATURE_CLOCKSOURCE2 || 3 || kvmclock available at msrs KVM_FEATURE_ASYNC_PF || 4 || async pf can be enabled by || || writing to msr 0x4b564d02 ------------------------------------------------------------------------------ +KVM_FEATURE_STEAL_TIME || 5 || steal time can be enabled by + || || writing to msr 0x4b564d03. +------------------------------------------------------------------------------ +KVM_FEATURE_PV_EOI || 6 || paravirtualized end of interrupt + || || handler can be enabled by writing + || || to msr 0x4b564d04. +------------------------------------------------------------------------------ +KVM_FEATURE_PV_UNHALT || 7 || guest checks this feature bit + || || before enabling paravirtualized + || || spinlock support. +------------------------------------------------------------------------------ KVM_FEATURE_CLOCKSOURCE_STABLE_BIT || 24 || host will warn if no guest-side || || per-cpu warps are expected in || || kvmclock. diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt new file mode 100644 index 00000000000..7f4e91b1316 --- /dev/null +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -0,0 +1,73 @@ +ARM Virtual Generic Interrupt Controller (VGIC) +=============================================== + +Device types supported: + KVM_DEV_TYPE_ARM_VGIC_V2 ARM Generic Interrupt Controller v2.0 + +Only one VGIC instance may be instantiated through either this API or the +legacy KVM_CREATE_IRQCHIP api. The created VGIC will act as the VM interrupt +controller, requiring emulated user-space devices to inject interrupts to the +VGIC instead of directly to CPUs. + +Groups: + KVM_DEV_ARM_VGIC_GRP_ADDR + Attributes: + KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit) + Base address in the guest physical address space of the GIC distributor + register mappings. + + KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit) + Base address in the guest physical address space of the GIC virtual cpu + interface register mappings. + + KVM_DEV_ARM_VGIC_GRP_DIST_REGS + Attributes: + The attr field of kvm_device_attr encodes two values: + bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 | + values: | reserved | cpu id | offset | + + All distributor regs are (rw, 32-bit) + + The offset is relative to the "Distributor base address" as defined in the + GICv2 specs. Getting or setting such a register has the same effect as + reading or writing the register on the actual hardware from the cpu + specified with cpu id field. Note that most distributor fields are not + banked, but return the same value regardless of the cpu id used to access + the register. + Limitations: + - Priorities are not implemented, and registers are RAZ/WI + Errors: + -ENODEV: Getting or setting this register is not yet supported + -EBUSY: One or more VCPUs are running + + KVM_DEV_ARM_VGIC_GRP_CPU_REGS + Attributes: + The attr field of kvm_device_attr encodes two values: + bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 | + values: | reserved | cpu id | offset | + + All CPU interface regs are (rw, 32-bit) + + The offset specifies the offset from the "CPU interface base address" as + defined in the GICv2 specs. Getting or setting such a register has the + same effect as reading or writing the register on the actual hardware. + + The Active Priorities Registers APRn are implementation defined, so we set a + fixed format for our implementation that fits with the model of a "GICv2 + implementation without the security extensions" which we present to the + guest. This interface always exposes four register APR[0-3] describing the + maximum possible 128 preemption levels. The semantics of the register + indicate if any interrupts in a given preemption level are in the active + state by setting the corresponding bit. + + Thus, preemption level X has one or more active interrupts if and only if: + + APRn[X mod 32] == 0b1, where n = X / 32 + + Bits for undefined preemption levels are RAZ/WI. + + Limitations: + - Priorities are not implemented, and registers are RAZ/WI + Errors: + -ENODEV: Getting or setting this register is not yet supported + -EBUSY: One or more VCPUs are running diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt new file mode 100644 index 00000000000..4ceef53164b --- /dev/null +++ b/Documentation/virtual/kvm/devices/s390_flic.txt @@ -0,0 +1,91 @@ +FLIC (floating interrupt controller) +==================================== + +FLIC handles floating (non per-cpu) interrupts, i.e. I/O, service and some +machine check interruptions. All interrupts are stored in a per-vm list of +pending interrupts. FLIC performs operations on this list. + +Only one FLIC instance may be instantiated. + +FLIC provides support to +- add interrupts (KVM_DEV_FLIC_ENQUEUE) +- inspect currently pending interrupts (KVM_FLIC_GET_ALL_IRQS) +- purge all pending floating interrupts (KVM_DEV_FLIC_CLEAR_IRQS) +- enable/disable for the guest transparent async page faults +- register and modify adapter interrupt sources (KVM_DEV_FLIC_ADAPTER_*) + +Groups: + KVM_DEV_FLIC_ENQUEUE + Passes a buffer and length into the kernel which are then injected into + the list of pending interrupts. + attr->addr contains the pointer to the buffer and attr->attr contains + the length of the buffer. + The format of the data structure kvm_s390_irq as it is copied from userspace + is defined in usr/include/linux/kvm.h. + + KVM_DEV_FLIC_GET_ALL_IRQS + Copies all floating interrupts into a buffer provided by userspace. + When the buffer is too small it returns -ENOMEM, which is the indication + for userspace to try again with a bigger buffer. + All interrupts remain pending, i.e. are not deleted from the list of + currently pending interrupts. + attr->addr contains the userspace address of the buffer into which all + interrupt data will be copied. + attr->attr contains the size of the buffer in bytes. + + KVM_DEV_FLIC_CLEAR_IRQS + Simply deletes all elements from the list of currently pending floating + interrupts. No interrupts are injected into the guest. + + KVM_DEV_FLIC_APF_ENABLE + Enables async page faults for the guest. So in case of a major page fault + the host is allowed to handle this async and continues the guest. + + KVM_DEV_FLIC_APF_DISABLE_WAIT + Disables async page faults for the guest and waits until already pending + async page faults are done. This is necessary to trigger a completion interrupt + for every init interrupt before migrating the interrupt list. + + KVM_DEV_FLIC_ADAPTER_REGISTER + Register an I/O adapter interrupt source. Takes a kvm_s390_io_adapter + describing the adapter to register: + +struct kvm_s390_io_adapter { + __u32 id; + __u8 isc; + __u8 maskable; + __u8 swap; + __u8 pad; +}; + + id contains the unique id for the adapter, isc the I/O interruption subclass + to use, maskable whether this adapter may be masked (interrupts turned off) + and swap whether the indicators need to be byte swapped. + + + KVM_DEV_FLIC_ADAPTER_MODIFY + Modifies attributes of an existing I/O adapter interrupt source. Takes + a kvm_s390_io_adapter_req specifiying the adapter and the operation: + +struct kvm_s390_io_adapter_req { + __u32 id; + __u8 type; + __u8 mask; + __u16 pad0; + __u64 addr; +}; + + id specifies the adapter and type the operation. The supported operations + are: + + KVM_S390_IO_ADAPTER_MASK + mask or unmask the adapter, as specified in mask + + KVM_S390_IO_ADAPTER_MAP + perform a gmap translation for the guest address provided in addr, + pin a userspace page for the translated address and add it to the + list of mappings + + KVM_S390_IO_ADAPTER_UNMAP + release a userspace page for the translated address specified in addr + from the list of mappings diff --git a/Documentation/virtual/kvm/devices/vfio.txt b/Documentation/virtual/kvm/devices/vfio.txt new file mode 100644 index 00000000000..ef51740c67c --- /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/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt new file mode 100644 index 00000000000..0d16f96c0ea --- /dev/null +++ b/Documentation/virtual/kvm/devices/vm.txt @@ -0,0 +1,26 @@ +Generic vm interface +==================================== + +The virtual machine "device" also accepts the ioctls KVM_SET_DEVICE_ATTR, +KVM_GET_DEVICE_ATTR, and KVM_HAS_DEVICE_ATTR. The interface uses the same +struct kvm_device_attr as other devices, but targets VM-wide settings +and controls. + +The groups and attributes per virtual machine, if any, are architecture +specific. + +1. GROUP: KVM_S390_VM_MEM_CTRL +Architectures: s390 + +1.1. ATTRIBUTE: KVM_S390_VM_MEM_CTRL +Parameters: none +Returns: -EBUSY if already a vcpus is defined, otherwise 0 + +Enables CMMA for the virtual machine + +1.2. ATTRIBUTE: KVM_S390_VM_CLR_CMMA +Parameteres: none +Returns: 0 + +Clear the CMMA status for all guest pages, so any pages the guest marked +as unused are again used any may not be reclaimed by the host. diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt index ea113b5d87a..c8d040e2704 100644 --- a/Documentation/virtual/kvm/hypercalls.txt +++ b/Documentation/virtual/kvm/hypercalls.txt @@ -17,6 +17,9 @@ S390: S390 uses diagnose instruction as hypercall (0x500) along with hypercall number in R1. + For further information on the S390 diagnose call as supported by KVM, + refer to Documentation/virtual/kvm/s390-diag.txt. + PowerPC: It uses R3-R10 and hypercall number in R11. R4-R11 are used as output registers. Return value is placed in R3. @@ -64,3 +67,17 @@ Purpose: To enable communication between the hypervisor and guest there is a shared page that contains parts of supervisor visible register state. The guest can map this shared page to access its supervisor register through memory using this hypercall. + +5. KVM_HC_KICK_CPU +------------------------ +Architecture: x86 +Status: active +Purpose: Hypercall used to wakeup a vcpu from HLT state +Usage example : A vcpu of a paravirtualized guest that is busywaiting in guest +kernel mode for an event to occur (ex: a spinlock to become available) can +execute HLT instruction once it has busy-waited for more than a threshold +time-interval. Execution of HLT instruction would cause the hypervisor to put +the vcpu to sleep until occurrence of an appropriate event. Another vcpu of the +same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall, +specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0) +is used in the hypercall for future use. diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index 41b7ac9884b..d68af4dc300 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -112,7 +112,7 @@ The Dirty bit is lost in this case. In order to avoid this kind of issue, we always treat the spte as "volatile" if it can be updated out of mmu-lock, see spte_has_volatile_bits(), it means, -the spte is always atomicly updated in this case. +the spte is always atomically updated in this case. 3): flush tlbs due to spte updated If the spte is updated from writable to readonly, we should flush all TLBs, @@ -125,17 +125,21 @@ be flushed caused by this reason in mmu_spte_update() since this is a common function to update spte (present -> present). Since the spte is "volatile" if it can be updated out of mmu-lock, we always -atomicly update the spte, the race caused by fast page fault can be avoided, +atomically update the spte, the race caused by fast page fault can be avoided, See the comments in spte_has_volatile_bits() and mmu_spte_update(). 3. Reference ------------ 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. diff --git a/Documentation/virtual/kvm/mmu.txt b/Documentation/virtual/kvm/mmu.txt index 43fcb761ed1..29089417614 100644 --- a/Documentation/virtual/kvm/mmu.txt +++ b/Documentation/virtual/kvm/mmu.txt @@ -191,12 +191,12 @@ Shadow pages contain the following information: A counter keeping track of how many hardware registers (guest cr3 or pdptrs) are now pointing at the page. While this counter is nonzero, the page cannot be destroyed. See role.invalid. - multimapped: - Whether there exist multiple sptes pointing at this page. - parent_pte/parent_ptes: - If multimapped is zero, parent_pte points at the single spte that points at - this page's spt. Otherwise, parent_ptes points at a data structure - with a list of parent_ptes. + parent_ptes: + The reverse mapping for the pte/ptes pointing at this page's spt. If + parent_ptes bit 0 is zero, only one spte points at this pages and + parent_ptes points at this single spte, otherwise, there exists multiple + sptes pointing at this page and (parent_ptes & ~0x1) points at a data + structure with a list of parent_ptes. unsync: If true, then the translations in this page may not match the guest's translation. This is equivalent to the state of the tlb when a pte is @@ -210,6 +210,24 @@ Shadow pages contain the following information: A bitmap indicating which sptes in spt point (directly or indirectly) at pages that may be unsynchronized. Used to quickly locate all unsychronized pages reachable from a given page. + mmu_valid_gen: + Generation number of the page. It is compared with kvm->arch.mmu_valid_gen + during hash table lookup, and used to skip invalidated shadow pages (see + "Zapping all pages" below.) + clear_spte_count: + Only present on 32-bit hosts, where a 64-bit spte cannot be written + atomically. The reader uses this while running out of the MMU lock + to detect in-progress updates and retry them until the writer has + finished the write. + write_flooding_count: + A guest may write to a page table many times, causing a lot of + emulations if the page needs to be write-protected (see "Synchronized + and unsynchronized pages" below). Leaf pages can be unsynchronized + so that they do not trigger frequent emulation, but this is not + possible for non-leafs. This field counts the number of emulations + since the last time the page table was actually used; if emulation + is triggered too frequently on this page, KVM will unmap the page + to avoid emulation in the future. Reverse map =========== @@ -258,14 +276,26 @@ This is the most complicated event. The cause of a page fault can be: Handling a page fault is performed as follows: + - if the RSV bit of the error code is set, the page fault is caused by guest + accessing MMIO and cached MMIO information is available. + - walk shadow page table + - check for valid generation number in the spte (see "Fast invalidation of + MMIO sptes" below) + - cache the information to vcpu->arch.mmio_gva, vcpu->arch.access and + vcpu->arch.mmio_gfn, and call the emulator + - If both P bit and R/W bit of error code are set, this could possibly + be handled as a "fast page fault" (fixed without taking the MMU lock). See + the description in Documentation/virtual/kvm/locking.txt. - if needed, walk the guest page tables to determine the guest translation (gva->gpa or ngpa->gpa) - if permissions are insufficient, reflect the fault back to the guest - determine the host page - - if this is an mmio request, there is no host page; call the emulator - to emulate the instruction instead + - if this is an mmio request, there is no host page; cache the info to + vcpu->arch.mmio_gva, vcpu->arch.access and vcpu->arch.mmio_gfn - walk the shadow page table to find the spte for the translation, instantiating missing intermediate page tables as necessary + - If this is an mmio request, cache the mmio info to the spte and set some + reserved bit on the spte (see callers of kvm_mmu_set_mmio_spte_mask) - try to unsynchronize the page - if successful, we can let the guest continue and modify the gpte - emulate the instruction @@ -351,6 +381,51 @@ causes its write_count to be incremented, thus preventing instantiation of a large spte. The frames at the end of an unaligned memory slot have artificially inflated ->write_counts so they can never be instantiated. +Zapping all pages (page generation count) +========================================= + +For the large memory guests, walking and zapping all pages is really slow +(because there are a lot of pages), and also blocks memory accesses of +all VCPUs because it needs to hold the MMU lock. + +To make it be more scalable, kvm maintains a global generation number +which is stored in kvm->arch.mmu_valid_gen. Every shadow page stores +the current global generation-number into sp->mmu_valid_gen when it +is created. Pages with a mismatching generation number are "obsolete". + +When KVM need zap all shadow pages sptes, it just simply increases the global +generation-number then reload root shadow pages on all vcpus. As the VCPUs +create new shadow page tables, the old pages are not used because of the +mismatching generation number. + +KVM then walks through all pages and zaps obsolete pages. While the zap +operation needs to take the MMU lock, the lock can be released periodically +so that the VCPUs can make progress. + +Fast invalidation of MMIO sptes +=============================== + +As mentioned in "Reaction to events" above, kvm will cache MMIO +information in leaf sptes. When a new memslot is added or an existing +memslot is changed, this information may become stale and needs to be +invalidated. This also needs to hold the MMU lock while walking all +shadow pages, and is made more scalable with a similar technique. + +MMIO sptes have a few spare bits, which are used to store a +generation number. The global generation number is stored in +kvm_memslots(kvm)->generation, and increased whenever guest memory info +changes. This generation number is distinct from the one described in +the previous section. + +When KVM finds an MMIO spte, it checks the generation number of the spte. +If the generation number of the spte does not equal the global generation +number, it will ignore the cached MMIO information and handle the page +fault through the slow path. + +Since only 19 bits are used to store generation-number on mmio spte, all +pages are zapped when there is an overflow. + + Further reading =============== diff --git a/Documentation/virtual/kvm/ppc-pv.txt b/Documentation/virtual/kvm/ppc-pv.txt index 4cd076febb0..319560646f3 100644 --- a/Documentation/virtual/kvm/ppc-pv.txt +++ b/Documentation/virtual/kvm/ppc-pv.txt @@ -94,10 +94,24 @@ a bitmap of available features inside the magic page. The following enhancements to the magic page are currently available: KVM_MAGIC_FEAT_SR Maps SR registers r/w in the magic page + KVM_MAGIC_FEAT_MAS0_TO_SPRG7 Maps MASn, ESR, PIR and high SPRGs For enhanced features in the magic page, please check for the existence of the feature before using them! +Magic page flags +================ + +In addition to features that indicate whether a host is capable of a particular +feature we also have a channel for a guest to tell the guest whether it's capable +of something. This is what we call "flags". + +Flags are passed to the host in the low 12 bits of the Effective Address. + +The following flags are currently available for a guest to expose: + + MAGIC_PAGE_FLAG_NOT_MAPPED_NX Guest handles NX bits correclty wrt magic page + MSR bits ======== @@ -115,7 +129,7 @@ If any other bit changes in the MSR, please still use mtmsr(d). Patched instructions ==================== -The "ld" and "std" instructions are transormed to "lwz" and "stw" instructions +The "ld" and "std" instructions are transformed to "lwz" and "stw" instructions respectively on 32 bit systems with an added offset of 4 to accommodate for big endianness. diff --git a/Documentation/virtual/kvm/s390-diag.txt b/Documentation/virtual/kvm/s390-diag.txt new file mode 100644 index 00000000000..48c4921794e --- /dev/null +++ b/Documentation/virtual/kvm/s390-diag.txt @@ -0,0 +1,82 @@ +The s390 DIAGNOSE call on KVM +============================= + +KVM on s390 supports the DIAGNOSE call for making hypercalls, both for +native hypercalls and for selected hypercalls found on other s390 +hypervisors. + +Note that bits are numbered as by the usual s390 convention (most significant +bit on the left). + + +General remarks +--------------- + +DIAGNOSE calls by the guest cause a mandatory intercept. This implies +all supported DIAGNOSE calls need to be handled by either KVM or its +userspace. + +All DIAGNOSE calls supported by KVM use the RS-a format: + +-------------------------------------- +| '83' | R1 | R3 | B2 | D2 | +-------------------------------------- +0 8 12 16 20 31 + +The second-operand address (obtained by the base/displacement calculation) +is not used to address data. Instead, bits 48-63 of this address specify +the function code, and bits 0-47 are ignored. + +The supported DIAGNOSE function codes vary by the userspace used. For +DIAGNOSE function codes not specific to KVM, please refer to the +documentation for the s390 hypervisors defining them. + + +DIAGNOSE function code 'X'500' - KVM virtio functions +----------------------------------------------------- + +If the function code specifies 0x500, various virtio-related functions +are performed. + +General register 1 contains the virtio subfunction code. Supported +virtio subfunctions depend on KVM's userspace. Generally, userspace +provides either s390-virtio (subcodes 0-2) or virtio-ccw (subcode 3). + +Upon completion of the DIAGNOSE instruction, general register 2 contains +the function's return code, which is either a return code or a subcode +specific value. + +Subcode 0 - s390-virtio notification and early console printk + Handled by userspace. + +Subcode 1 - s390-virtio reset + Handled by userspace. + +Subcode 2 - s390-virtio set status + Handled by userspace. + +Subcode 3 - virtio-ccw notification + Handled by either userspace or KVM (ioeventfd case). + + General register 2 contains a subchannel-identification word denoting + the subchannel of the virtio-ccw proxy device to be notified. + + General register 3 contains the number of the virtqueue to be notified. + + General register 4 contains a 64bit identifier for KVM usage (the + kvm_io_bus cookie). If general register 4 does not contain a valid + identifier, it is ignored. + + After completion of the DIAGNOSE call, general register 2 may contain + a 64bit identifier (in the kvm_io_bus cookie case). + + See also the virtio standard for a discussion of this hypercall. + + +DIAGNOSE function code 'X'501 - KVM breakpoint +---------------------------------------------- + +If the function code specifies 0x501, breakpoint functions may be performed. +This function code is handled by userspace. + +This diagnose function code has no subfunctions and uses no parameters. diff --git a/Documentation/virtual/kvm/timekeeping.txt b/Documentation/virtual/kvm/timekeeping.txt index df8946377cb..76808a17ad8 100644 --- a/Documentation/virtual/kvm/timekeeping.txt +++ b/Documentation/virtual/kvm/timekeeping.txt @@ -467,7 +467,7 @@ at any time. This causes problems as the passage of real time, the injection of machine interrupts and the associated clock sources are no longer completely synchronized with real time. -This same problem can occur on native harware to a degree, as SMM mode may +This same problem can occur on native hardware to a degree, as SMM mode may steal cycles from the naturally on X86 systems when SMM mode is used by the BIOS, but not in such an extreme fashion. However, the fact that SMM mode may cause similar problems to virtualization makes it a good justification for diff --git a/Documentation/virtual/uml/UserModeLinux-HOWTO.txt b/Documentation/virtual/uml/UserModeLinux-HOWTO.txt index a5f8436753e..f4099ca6b48 100644 --- a/Documentation/virtual/uml/UserModeLinux-HOWTO.txt +++ b/Documentation/virtual/uml/UserModeLinux-HOWTO.txt @@ -3127,7 +3127,7 @@ at process_kern.c:156 #3 0x1006a052 in switch_to (prev=0x50072000, next=0x507e8000, last=0x50072000) at process_kern.c:161 - #4 0x10001d12 in schedule () at sched.c:777 + #4 0x10001d12 in schedule () at core.c:777 #5 0x1006a744 in __down (sem=0x507d241c) at semaphore.c:71 #6 0x1006aa10 in __down_failed () at semaphore.c:157 #7 0x1006c5d8 in segv_handler (sc=0x5006e940) at trap_user.c:174 @@ -3191,7 +3191,7 @@ at process_kern.c:161 161 _switch_to(prev, next); (gdb) - #4 0x10001d12 in schedule () at sched.c:777 + #4 0x10001d12 in schedule () at core.c:777 777 switch_to(prev, next, prev); (gdb) #5 0x1006a744 in __down (sem=0x507d241c) at semaphore.c:71 |