From: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
For now, this command returns only the number of online vCPUs.
The introspection tool uses the vCPU index to specify to which vCPU
the introspection command applies to.
Signed-off-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
---
Documentation/virt/kvm/kvmi.rst | 18 ++++++++++
include/uapi/linux/kvmi.h | 6 ++++
.../testing/selftests/kvm/x86_64/kvmi_test.c | 35 +++++++++++++++++--
virt/kvm/introspection/kvmi_msg.c | 13 +++++++
4 files changed, 69 insertions(+), 3 deletions(-)
diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index a2cda3268da0..a81f22cb8c18 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -323,3 +323,21 @@ This command is always allowed.
* -KVM_ENOENT - the event specified by ``id`` is unsupported
* -KVM_EPERM - the event specified by ``id`` is disallowed
* -KVM_EINVAL - the padding is not zero
+
+4. KVMI_VM_GET_INFO
+-------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters: none
+:Returns:
+
+::
+
+ struct kvmi_error_code;
+ struct kvmi_vm_get_info_reply {
+ __u32 vcpu_count;
+ __u32 padding[3];
+ };
+
+Returns the number of online vCPUs.
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index e55a0fa66ac5..eabaf7cea1df 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -17,6 +17,7 @@ enum {
KVMI_GET_VERSION = 1,
KVMI_VM_CHECK_COMMAND = 2,
KVMI_VM_CHECK_EVENT = 3,
+ KVMI_VM_GET_INFO = 4,
KVMI_NUM_MESSAGES
};
@@ -63,4 +64,9 @@ struct kvmi_vm_check_event {
__u32 padding2;
};
+struct kvmi_vm_get_info_reply {
+ __u32 vcpu_count;
+ __u32 padding[3];
+};
+
#endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 28216c4e8b9d..1f4a165ab640 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -84,6 +84,16 @@ static void set_command_perm(struct kvm_vm *vm, __s32 id, __u32 allow,
"KVM_INTROSPECTION_COMMAND");
}
+static void disallow_command(struct kvm_vm *vm, __s32 id)
+{
+ set_command_perm(vm, id, 0, 0);
+}
+
+static void allow_command(struct kvm_vm *vm, __s32 id)
+{
+ set_command_perm(vm, id, 1, 0);
+}
+
static void hook_introspection(struct kvm_vm *vm)
{
__u32 allow = 1, disallow = 0, allow_inval = 2;
@@ -258,14 +268,18 @@ static void cmd_vm_check_command(__u16 id, __u16 padding, int expected_err)
-r, kvm_strerror(-r), expected_err);
}
-static void test_cmd_vm_check_command(void)
+static void test_cmd_vm_check_command(struct kvm_vm *vm)
{
- __u16 valid_id = KVMI_GET_VERSION, invalid_id = 0xffff;
+ __u16 valid_id = KVMI_VM_GET_INFO, invalid_id = 0xffff;
__u16 padding = 1, no_padding = 0;
cmd_vm_check_command(valid_id, no_padding, 0);
cmd_vm_check_command(valid_id, padding, -KVM_EINVAL);
cmd_vm_check_command(invalid_id, no_padding, -KVM_ENOENT);
+
+ disallow_command(vm, valid_id);
+ cmd_vm_check_command(valid_id, no_padding, -KVM_EPERM);
+ allow_command(vm, valid_id);
}
static void cmd_vm_check_event(__u16 id, __u16 padding, int expected_err)
@@ -295,6 +309,20 @@ static void test_cmd_vm_check_event(void)
cmd_vm_check_event(invalid_id, no_padding, -KVM_ENOENT);
}
+static void test_cmd_vm_get_info(void)
+{
+ struct kvmi_vm_get_info_reply rpl;
+ struct kvmi_msg_hdr req;
+
+ test_vm_command(KVMI_VM_GET_INFO, &req, sizeof(req), &rpl,
+ sizeof(rpl));
+ TEST_ASSERT(rpl.vcpu_count == 1,
+ "Unexpected number of vCPU count %u\n",
+ rpl.vcpu_count);
+
+ pr_info("vcpu count: %u\n", rpl.vcpu_count);
+}
+
static void test_introspection(struct kvm_vm *vm)
{
setup_socket();
@@ -302,8 +330,9 @@ static void test_introspection(struct kvm_vm *vm)
test_cmd_invalid();
test_cmd_get_version();
- test_cmd_vm_check_command();
+ test_cmd_vm_check_command(vm);
test_cmd_vm_check_event();
+ test_cmd_vm_get_info();
unhook_introspection(vm);
}
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 86c356afc154..3df18f7965c0 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -150,6 +150,18 @@ static int handle_vm_check_event(struct kvm_introspection *kvmi,
return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
}
+static int handle_vm_get_info(struct kvm_introspection *kvmi,
+ const struct kvmi_msg_hdr *msg,
+ const void *req)
+{
+ struct kvmi_vm_get_info_reply rpl;
+
+ memset(&rpl, 0, sizeof(rpl));
+ rpl.vcpu_count = atomic_read(&kvmi->kvm->online_vcpus);
+
+ return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl));
+}
+
/*
* These commands are executed by the receiving thread.
*/
@@ -158,6 +170,7 @@ static int(*const msg_vm[])(struct kvm_introspection *,
[KVMI_GET_VERSION] = handle_get_version,
[KVMI_VM_CHECK_COMMAND] = handle_vm_check_command,
[KVMI_VM_CHECK_EVENT] = handle_vm_check_event,
+ [KVMI_VM_GET_INFO] = handle_vm_get_info,
};
static bool is_vm_command(u16 id)
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