diff options
Diffstat (limited to 'Documentation/virtual')
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 90 |
1 files changed, 74 insertions, 16 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 7a04216d7278..da3c395ed174 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1472,9 +1472,11 @@ struct kvm_irq_routing_entry { #define KVM_IRQ_ROUTING_HV_SINT 4 flags: -- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI - routing entry type, specifies that the devid field contains - a valid value. +- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry + type, specifies that the devid field contains a valid value. The per-VM + KVM_CAP_MSI_DEVID capability advertises the requirement to provide + the device ID. If this capability is not available, userspace should + never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. - zero otherwise struct kvm_irq_routing_irqchip { @@ -1492,13 +1494,14 @@ struct kvm_irq_routing_msi { }; }; -devid: If KVM_MSI_VALID_DEVID is set, contains a unique device identifier - for the device that wrote the MSI message. - For PCI, this is usually a BFD identifier in the lower 16 bits. +If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier +for the device that wrote the MSI message. For PCI, this is usually a +BFD identifier in the lower 16 bits. -The per-VM KVM_CAP_MSI_DEVID capability advertises the requirement to -provide the device ID. If this capability is not set, userland cannot -rely on the kernel to allow the KVM_MSI_VALID_DEVID flag being set. +On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS +feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, +address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of +address_hi must be zero. struct kvm_irq_routing_s390_adapter { __u64 ind_addr; @@ -1601,6 +1604,17 @@ struct kvm_lapic_state { Reads the Local APIC registers and copies them into the input argument. The data format and layout are the same as documented in the architecture manual. +If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is +enabled, then the format of APIC_ID register depends on the APIC mode +(reported by MSR_IA32_APICBASE) of its VCPU. x2APIC stores APIC ID in +the APIC_ID register (bytes 32-35). xAPIC only allows an 8-bit APIC ID +which is stored in bits 31-24 of the APIC register, or equivalently in +byte 35 of struct kvm_lapic_state's regs field. KVM_GET_LAPIC must then +be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR. + +If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state +always uses xAPIC format. + 4.58 KVM_SET_LAPIC @@ -1618,6 +1632,10 @@ struct kvm_lapic_state { Copies the input argument into the Local APIC registers. The data format and layout are the same as documented in the architecture manual. +The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's +regs field) depends on the state of the KVM_CAP_X2APIC_API capability. +See the note in KVM_GET_LAPIC. + 4.59 KVM_IOEVENTFD @@ -2197,14 +2215,18 @@ struct kvm_msi { __u8 pad[12]; }; -flags: KVM_MSI_VALID_DEVID: devid contains a valid value -devid: If KVM_MSI_VALID_DEVID is set, contains a unique device identifier - for the device that wrote the MSI message. - For PCI, this is usually a BFD identifier in the lower 16 bits. +flags: KVM_MSI_VALID_DEVID: devid contains a valid value. The per-VM + KVM_CAP_MSI_DEVID capability advertises the requirement to provide + the device ID. If this capability is not available, userspace + should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. -The per-VM KVM_CAP_MSI_DEVID capability advertises the need to provide -the device ID. If this capability is not set, userland cannot rely on -the kernel to allow the KVM_MSI_VALID_DEVID flag being set. +If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier +for the device that wrote the MSI message. For PCI, this is usually a +BFD identifier in the lower 16 bits. + +On x86, address_hi is ignored unless the KVM_CAP_X2APIC_API capability is +enabled. If it is enabled, address_hi bits 31-8 provide bits 31-8 of the +destination id. Bits 7-0 of address_hi must be zero. 4.71 KVM_CREATE_PIT2 @@ -3841,6 +3863,42 @@ Allows use of runtime-instrumentation introduced with zEC12 processor. Will return -EINVAL if the machine does not support runtime-instrumentation. Will return -EBUSY if a VCPU has already been created. +7.7 KVM_CAP_X2APIC_API + +Architectures: x86 +Parameters: args[0] - features that should be enabled +Returns: 0 on success, -EINVAL when args[0] contains invalid features + +Valid feature flags in args[0] are + +#define KVM_X2APIC_API_USE_32BIT_IDS (1ULL << 0) +#define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK (1ULL << 1) + +Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of +KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC, +allowing the use of 32-bit APIC IDs. See KVM_CAP_X2APIC_API in their +respective sections. + +KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work +in logical mode or with more than 255 VCPUs. Otherwise, KVM treats 0xff +as a broadcast even in x2APIC mode in order to support physical x2APIC +without interrupt remapping. This is undesirable in logical mode, +where 0xff represents CPUs 0-7 in cluster 0. + +7.8 KVM_CAP_S390_USER_INSTR0 + +Architectures: s390 +Parameters: none + +With this capability enabled, all illegal instructions 0x0000 (2 bytes) will +be intercepted and forwarded to user space. User space can use this +mechanism e.g. to realize 2-byte software breakpoints. The kernel will +not inject an operating exception for these instructions, user space has +to take care of that. + +This capability can be enabled dynamically even if VCPUs were already +created and are running. + 8. Other capabilities. ---------------------- |