This is used by the introspection tool to check the hardware support for the single step feature. Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx> --- Documentation/virt/kvm/kvmi.rst | 15 +++++++++++++-- arch/x86/include/uapi/asm/kvmi.h | 5 +++++ arch/x86/kvm/kvmi.c | 5 +++++ include/uapi/linux/kvmi.h | 1 + tools/testing/selftests/kvm/x86_64/kvmi_test.c | 6 ++++++ virt/kvm/introspection/kvmi_int.h | 1 + virt/kvm/introspection/kvmi_msg.c | 2 ++ 7 files changed, 33 insertions(+), 2 deletions(-) diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index b12affb0d64f..54cb3fbe184e 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -243,10 +243,21 @@ The vCPU commands start with:: struct kvmi_get_version_reply { __u32 version; __u32 max_msg_size; + struct kvmi_features features; }; -Returns the introspection API version and the largest accepted message -size (useful for variable length messages). +For x86 + +:: + + struct kvmi_features { + __u8 singlestep; + __u8 padding[7]; + }; + +Returns the introspection API version, the largest accepted message size +(useful for variable length messages) and some of the hardware supported +features. This command is always allowed and successful. diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h index 6ef144ddb4bb..c5a2cb1b54f1 100644 --- a/arch/x86/include/uapi/asm/kvmi.h +++ b/arch/x86/include/uapi/asm/kvmi.h @@ -159,4 +159,9 @@ struct kvmi_vcpu_event_msr_reply { __u64 new_val; }; +struct kvmi_features { + __u8 singlestep; + __u8 padding[7]; +}; + #endif /* _UAPI_ASM_X86_KVMI_H */ diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c index 6432c40817d2..eee874890e29 100644 --- a/arch/x86/kvm/kvmi.c +++ b/arch/x86/kvm/kvmi.c @@ -1084,3 +1084,8 @@ static void kvmi_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot, kvmi_put(kvm); } + +void kvmi_arch_features(struct kvmi_features *feat) +{ + feat->singlestep = !!kvm_x86_ops.control_singlestep; +} diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h index bb6265e4539a..b594463795c6 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -102,6 +102,7 @@ struct kvmi_error_code { struct kvmi_get_version_reply { __u32 version; __u32 max_msg_size; + struct kvmi_features features; }; struct kvmi_vm_check_command { diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c index 9cf099b38bdf..f7735e3ea9e8 100644 --- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c @@ -59,6 +59,8 @@ struct vcpu_worker_data { bool restart_on_shutdown; }; +static struct kvmi_features features; + typedef void (*fct_pf_event)(struct kvm_vm *vm, struct kvmi_msg_hdr *hdr, struct pf_ev *ev, struct vcpu_reply *rpl); @@ -443,6 +445,10 @@ static void test_cmd_get_version(void) pr_debug("KVMI version: %u\n", rpl.version); pr_debug("Max message size: %u\n", rpl.max_msg_size); + + features = rpl.features; + + pr_debug("singlestep support: %u\n", features.singlestep); } static void cmd_vm_check_command(__u16 id, int expected_err) diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h index bf6545e66425..a51e7e4ed511 100644 --- a/virt/kvm/introspection/kvmi_int.h +++ b/virt/kvm/introspection/kvmi_int.h @@ -121,5 +121,6 @@ void kvmi_arch_update_page_tracking(struct kvm *kvm, struct kvmi_mem_access *m); void kvmi_arch_hook(struct kvm *kvm); void kvmi_arch_unhook(struct kvm *kvm); +void kvmi_arch_features(struct kvmi_features *feat); #endif diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c index 745d10981b6f..e2aef76bfd16 100644 --- a/virt/kvm/introspection/kvmi_msg.c +++ b/virt/kvm/introspection/kvmi_msg.c @@ -134,6 +134,8 @@ static int handle_get_version(struct kvm_introspection *kvmi, rpl.version = kvmi_version(); rpl.max_msg_size = KVMI_MAX_MSG_SIZE; + kvmi_arch_features(&rpl.features); + return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl)); }