diff options
Diffstat (limited to 'Documentation/virt')
| -rw-r--r-- | Documentation/virt/coco/sev-guest.rst | 20 | ||||
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 77 | ||||
| -rw-r--r-- | Documentation/virt/kvm/devices/vm.rst | 79 | ||||
| -rw-r--r-- | Documentation/virt/kvm/locking.rst | 2 |
4 files changed, 164 insertions, 14 deletions
diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst index bf593e88cfd9..68b0d2363af8 100644 --- a/Documentation/virt/coco/sev-guest.rst +++ b/Documentation/virt/coco/sev-guest.rst @@ -37,11 +37,11 @@ along with a description: the return value. General error numbers (-ENOMEM, -EINVAL) are not detailed, but errors with specific meanings are. -The guest ioctl should be issued on a file descriptor of the /dev/sev-guest device. -The ioctl accepts struct snp_user_guest_request. The input and output structure is -specified through the req_data and resp_data field respectively. If the ioctl fails -to execute due to a firmware error, then fw_err code will be set otherwise the -fw_err will be set to 0x00000000000000ff. +The guest ioctl should be issued on a file descriptor of the /dev/sev-guest +device. The ioctl accepts struct snp_user_guest_request. The input and +output structure is specified through the req_data and resp_data field +respectively. If the ioctl fails to execute due to a firmware error, then +the fw_error code will be set, otherwise fw_error will be set to -1. The firmware checks that the message sequence counter is one greater than the guests message sequence counter. If guest driver fails to increment message @@ -57,8 +57,14 @@ counter (e.g. counter overflow), then -EIO will be returned. __u64 req_data; __u64 resp_data; - /* firmware error code on failure (see psp-sev.h) */ - __u64 fw_err; + /* bits[63:32]: VMM error code, bits[31:0] firmware error code (see psp-sev.h) */ + union { + __u64 exitinfo2; + struct { + __u32 fw_error; + __u32 vmm_error; + }; + }; }; 2.1 SNP_GET_REPORT diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index a5c803f39832..add067793b90 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -5645,7 +5645,8 @@ with the KVM_XEN_VCPU_GET_ATTR ioctl. }; Copies Memory Tagging Extension (MTE) tags to/from guest tag memory. The -``guest_ipa`` and ``length`` fields must be ``PAGE_SIZE`` aligned. The ``addr`` +``guest_ipa`` and ``length`` fields must be ``PAGE_SIZE`` aligned. +``length`` must not be bigger than 2^31 - PAGE_SIZE bytes. The ``addr`` field must point to a buffer which the tags will be copied to or from. ``flags`` specifies the direction of copy, either ``KVM_ARM_TAGS_TO_GUEST`` or @@ -6029,6 +6030,44 @@ delivery must be provided via the "reg_aen" struct. The "pad" and "reserved" fields may be used for future extensions and should be set to 0s by userspace. +4.138 KVM_ARM_SET_COUNTER_OFFSET +-------------------------------- + +:Capability: KVM_CAP_COUNTER_OFFSET +:Architectures: arm64 +:Type: vm ioctl +:Parameters: struct kvm_arm_counter_offset (in) +:Returns: 0 on success, < 0 on error + +This capability indicates that userspace is able to apply a single VM-wide +offset to both the virtual and physical counters as viewed by the guest +using the KVM_ARM_SET_CNT_OFFSET ioctl and the following data structure: + +:: + + struct kvm_arm_counter_offset { + __u64 counter_offset; + __u64 reserved; + }; + +The offset describes a number of counter cycles that are subtracted from +both virtual and physical counter views (similar to the effects of the +CNTVOFF_EL2 and CNTPOFF_EL2 system registers, but only global). The offset +always applies to all vcpus (already created or created after this ioctl) +for this VM. + +It is userspace's responsibility to compute the offset based, for example, +on previous values of the guest counters. + +Any value other than 0 for the "reserved" field may result in an error +(-EINVAL) being returned. This ioctl can also return -EBUSY if any vcpu +ioctl is issued concurrently. + +Note that using this ioctl results in KVM ignoring subsequent userspace +writes to the CNTVCT_EL0 and CNTPCT_EL0 registers using the SET_ONE_REG +interface. No error will be returned, but the resulting offset will not be +applied. + 5. The kvm_run structure ======================== @@ -6218,15 +6257,40 @@ to the byte array. __u64 nr; __u64 args[6]; __u64 ret; - __u32 longmode; - __u32 pad; + __u64 flags; } hypercall; -Unused. This was once used for 'hypercall to userspace'. To implement -such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390). + +It is strongly recommended that userspace use ``KVM_EXIT_IO`` (x86) or +``KVM_EXIT_MMIO`` (all except s390) to implement functionality that +requires a guest to interact with host userpace. .. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO. +For arm64: +---------- + +SMCCC exits can be enabled depending on the configuration of the SMCCC +filter. See the Documentation/virt/kvm/devices/vm.rst +``KVM_ARM_SMCCC_FILTER`` for more details. + +``nr`` contains the function ID of the guest's SMCCC call. Userspace is +expected to use the ``KVM_GET_ONE_REG`` ioctl to retrieve the call +parameters from the vCPU's GPRs. + +Definition of ``flags``: + - ``KVM_HYPERCALL_EXIT_SMC``: Indicates that the guest used the SMC + conduit to initiate the SMCCC call. If this bit is 0 then the guest + used the HVC conduit for the SMCCC call. + + - ``KVM_HYPERCALL_EXIT_16BIT``: Indicates that the guest used a 16bit + instruction to initiate the SMCCC call. If this bit is 0 then the + guest used a 32bit instruction. An AArch64 guest always has this + bit set to 0. + +At the point of exit, PC points to the instruction immediately following +the trapping instruction. + :: /* KVM_EXIT_TPR_ACCESS */ @@ -7266,6 +7330,7 @@ and injected exceptions. will clear DR6.RTM. 7.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 +-------------------------------------- :Architectures: x86, arm64, mips :Parameters: args[0] whether feature should be enabled or not @@ -7456,7 +7521,7 @@ system fingerprint. To prevent userspace from circumventing such restrictions by running an enclave in a VM, KVM prevents access to privileged attributes by default. -See Documentation/x86/sgx.rst for more details. +See Documentation/arch/x86/sgx.rst for more details. 7.26 KVM_CAP_PPC_RPT_INVALIDATE ------------------------------- diff --git a/Documentation/virt/kvm/devices/vm.rst b/Documentation/virt/kvm/devices/vm.rst index 147efec626e5..9d726e60ec47 100644 --- a/Documentation/virt/kvm/devices/vm.rst +++ b/Documentation/virt/kvm/devices/vm.rst @@ -321,3 +321,82 @@ Allows userspace to query the status of migration mode. if it is enabled :Returns: -EFAULT if the given address is not accessible from kernel space; 0 in case of success. + +6. GROUP: KVM_ARM_VM_SMCCC_CTRL +=============================== + +:Architectures: arm64 + +6.1. ATTRIBUTE: KVM_ARM_VM_SMCCC_FILTER (w/o) +--------------------------------------------- + +:Parameters: Pointer to a ``struct kvm_smccc_filter`` + +:Returns: + + ====== =========================================== + EEXIST Range intersects with a previously inserted + or reserved range + EBUSY A vCPU in the VM has already run + EINVAL Invalid filter configuration + ENOMEM Failed to allocate memory for the in-kernel + representation of the SMCCC filter + ====== =========================================== + +Requests the installation of an SMCCC call filter described as follows:: + + enum kvm_smccc_filter_action { + KVM_SMCCC_FILTER_HANDLE = 0, + KVM_SMCCC_FILTER_DENY, + KVM_SMCCC_FILTER_FWD_TO_USER, + }; + + struct kvm_smccc_filter { + __u32 base; + __u32 nr_functions; + __u8 action; + __u8 pad[15]; + }; + +The filter is defined as a set of non-overlapping ranges. Each +range defines an action to be applied to SMCCC calls within the range. +Userspace can insert multiple ranges into the filter by using +successive calls to this attribute. + +The default configuration of KVM is such that all implemented SMCCC +calls are allowed. Thus, the SMCCC filter can be defined sparsely +by userspace, only describing ranges that modify the default behavior. + +The range expressed by ``struct kvm_smccc_filter`` is +[``base``, ``base + nr_functions``). The range is not allowed to wrap, +i.e. userspace cannot rely on ``base + nr_functions`` overflowing. + +The SMCCC filter applies to both SMC and HVC calls initiated by the +guest. The SMCCC filter gates the in-kernel emulation of SMCCC calls +and as such takes effect before other interfaces that interact with +SMCCC calls (e.g. hypercall bitmap registers). + +Actions: + + - ``KVM_SMCCC_FILTER_HANDLE``: Allows the guest SMCCC call to be + handled in-kernel. It is strongly recommended that userspace *not* + explicitly describe the allowed SMCCC call ranges. + + - ``KVM_SMCCC_FILTER_DENY``: Rejects the guest SMCCC call in-kernel + and returns to the guest. + + - ``KVM_SMCCC_FILTER_FWD_TO_USER``: The guest SMCCC call is forwarded + to userspace with an exit reason of ``KVM_EXIT_HYPERCALL``. + +The ``pad`` field is reserved for future use and must be zero. KVM may +return ``-EINVAL`` if the field is nonzero. + +KVM reserves the 'Arm Architecture Calls' range of function IDs and +will reject attempts to define a filter for any portion of these ranges: + + =========== =============== + Start End (inclusive) + =========== =============== + 0x8000_0000 0x8000_FFFF + 0xC000_0000 0xC000_FFFF + =========== =============== diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst index 14c4e9fa501d..8c77554e4896 100644 --- a/Documentation/virt/kvm/locking.rst +++ b/Documentation/virt/kvm/locking.rst @@ -21,7 +21,7 @@ The acquisition orders for mutexes are as follows: - kvm->mn_active_invalidate_count ensures that pairs of invalidate_range_start() and invalidate_range_end() callbacks use the same memslots array. kvm->slots_lock and kvm->slots_arch_lock - are taken on the waiting side in install_new_memslots, so MMU notifiers + are taken on the waiting side when modifying memslots, so MMU notifiers must not take either kvm->slots_lock or kvm->slots_arch_lock. For SRCU: |