From: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
Based on the common structure (kvmi_vcpu_hdr) used for all vCPU commands,
the receiving thread validates and dispatches the message to the proper
vCPU (adding the handling function to its jobs list).
Signed-off-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
Co-developed-by: Nicușor Cîțu <ncitu@xxxxxxxxxxxxxxx>
Signed-off-by: Nicușor Cîțu <ncitu@xxxxxxxxxxxxxxx>
Co-developed-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
---
Documentation/virt/kvm/kvmi.rst | 8 ++
include/uapi/linux/kvmi.h | 6 ++
virt/kvm/introspection/kvmi_int.h | 3 +
virt/kvm/introspection/kvmi_msg.c | 151 +++++++++++++++++++++++++++++-
4 files changed, 166 insertions(+), 2 deletions(-)
diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 60fa50585c36..38f566b07bb5 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -232,6 +232,14 @@ The following C structures are meant to be used directly when communicating
over the wire. The peer that detects any size mismatch should simply close
the connection and report the error.
+The commands related to vCPUs start with::
+
+ struct kvmi_vcpu_hdr {
+ __u16 vcpu;
+ __u16 padding1;
+ __u32 padding2;
+ }
+
1. KVMI_GET_VERSION
-------------------
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 3b8590c0fc98..b2cbefdb8b29 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -89,6 +89,12 @@ struct kvmi_vm_write_physical {
__u8 data[0];
};
+struct kvmi_vcpu_hdr {
+ __u16 vcpu;
+ __u16 padding1;
+ __u32 padding2;
+};
+
struct kvmi_event {
__u16 size;
__u16 vcpu;
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index e0d8256162f9..e7ebb4d67dd6 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -55,6 +55,9 @@ int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
void *kvmi_msg_alloc(void);
void *kvmi_msg_alloc_check(size_t size);
void kvmi_msg_free(void *addr);
+int kvmi_add_job(struct kvm_vcpu *vcpu,
+ void (*fct)(struct kvm_vcpu *vcpu, void *ctx),
+ void *ctx, void (*free_fct)(void *ctx));
int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
unsigned int event_id, bool enable);
int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, u64 size,
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 032b6b5b8000..94225153f7cc 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -8,6 +8,14 @@
#include <linux/net.h>
#include "kvmi_int.h"
+struct kvmi_vcpu_cmd_job {
+ struct {
+ struct kvmi_msg_hdr hdr;
+ struct kvmi_vcpu_hdr cmd;
+ } *msg;
+ struct kvm_vcpu *vcpu;
+};
+
static const char *const msg_IDs[] = {
[KVMI_GET_VERSION] = "KVMI_GET_VERSION",
[KVMI_VM_CHECK_COMMAND] = "KVMI_VM_CHECK_COMMAND",
@@ -123,6 +131,28 @@ static bool is_command_allowed(struct kvm_introspection *kvmi, int id)
return test_bit(id, kvmi->cmd_allow_mask);
}
+static bool invalid_vcpu_hdr(const struct kvmi_vcpu_hdr *hdr)
+{
+ return hdr->padding1 || hdr->padding2;
+}
+
+static int kvmi_get_vcpu(struct kvm_introspection *kvmi, unsigned int vcpu_idx,
+ struct kvm_vcpu **dest)
+{
+ struct kvm *kvm = kvmi->kvm;
+ struct kvm_vcpu *vcpu;
+
+ if (vcpu_idx >= atomic_read(&kvm->online_vcpus))
+ return -KVM_EINVAL;
+
+ vcpu = kvm_get_vcpu(kvm, vcpu_idx);
+ if (!vcpu)
+ return -KVM_EINVAL;
+
+ *dest = vcpu;
+ return 0;
+}
+
static int handle_get_version(struct kvm_introspection *kvmi,
const struct kvmi_msg_hdr *msg, const void *req)
{
@@ -265,16 +295,67 @@ static int(*const msg_vm[])(struct kvm_introspection *,
[KVMI_VM_WRITE_PHYSICAL] = handle_write_physical,
};
+/*
+ * These commands are executed on the vCPU thread. The receiving thread
+ * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
+ * and signals the vCPU to handle the command (which includes
+ * sending back the reply).
+ */
+static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
+ const struct kvmi_msg_hdr *, const void *) = {
+};
+
+static void kvmi_job_vcpu_cmd(struct kvm_vcpu *vcpu, void *ctx)
+{
+ struct kvmi_vcpu_cmd_job *job = ctx;
+ size_t id = job->msg->hdr.id;
+ int err;
+
+ job->vcpu = vcpu;
+
+ err = msg_vcpu[id](job, &job->msg->hdr, job->msg + 1);
+
+ if (err) {
+ struct kvm_introspection *kvmi = KVMI(vcpu->kvm);
+
+ kvmi_err(kvmi,
+ "%s: cmd id: %zu (%s), err: %d\n", __func__,
+ id, id2str(id), err);
+ kvmi_sock_shutdown(kvmi);
+ }
+}
+
+static void kvmi_free_ctx(void *_ctx)
+{
+ const struct kvmi_vcpu_cmd_job *ctx = _ctx;
+
+ kvmi_msg_free(ctx->msg);
+ kfree(ctx);
+}
+
+static int kvmi_msg_queue_to_vcpu(struct kvm_vcpu *vcpu,
+ const struct kvmi_vcpu_cmd_job *cmd)
+{
+ return kvmi_add_job(vcpu, kvmi_job_vcpu_cmd, (void *)cmd,
+ kvmi_free_ctx);
+}
+
static bool is_vm_message(u16 id)
{
return id < ARRAY_SIZE(msg_vm) && !!msg_vm[id];
}
+static bool is_vcpu_message(u16 id)
+{
+ return id < ARRAY_SIZE(msg_vcpu) && !!msg_vcpu[id];
+}
+
static bool is_unsupported_message(u16 id)
{
bool supported;
- supported = is_known_message(id) && is_vm_message(id);
+ supported = is_known_message(id) &&
+ (is_vm_message(id) || is_vcpu_message(id));
return !supported;
}
@@ -344,12 +425,78 @@ static int kvmi_msg_dispatch_vm_cmd(struct kvm_introspection *kvmi,
return msg_vm[msg->id](kvmi, msg, msg + 1);
}
+static bool vcpu_can_handle_commands(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.mp_state != KVM_MP_STATE_UNINITIALIZED;
+}
+
+static int kvmi_get_vcpu_if_ready(struct kvm_introspection *kvmi,
+ unsigned int vcpu_idx,
+ struct kvm_vcpu **vcpu)
+{
+ int err;
+
+ err = kvmi_get_vcpu(kvmi, vcpu_idx, vcpu);
+
+ if (!err && !vcpu_can_handle_commands(*vcpu))
+ err = -KVM_EAGAIN;
+
+ return err;
+}
+
+static int kvmi_msg_dispatch_vcpu_job(struct kvm_introspection *kvmi,
+ struct kvmi_vcpu_cmd_job *job,
+ bool *queued)
+{
+ struct kvmi_vcpu_hdr *cmd = &job->msg->cmd;
+ struct kvmi_msg_hdr *hdr = &job->msg->hdr;
+ struct kvm_vcpu *vcpu = NULL;
+ int err;
+
+ if (invalid_vcpu_hdr(cmd))
+ return -KVM_EINVAL;
+
+ err = kvmi_get_vcpu_if_ready(kvmi, cmd->vcpu, &vcpu);
+
+ if (err)
+ return kvmi_msg_vm_reply(kvmi, hdr, err, NULL, 0);
+
+ err = kvmi_msg_queue_to_vcpu(vcpu, job);
+ if (!err)
+ *queued = true;
+ return err;
+}
+
+static int kvmi_msg_dispatch_vcpu_cmd(struct kvm_introspection *kvmi,
+ struct kvmi_msg_hdr *msg,
+ bool *queued)
+{
+ struct kvmi_vcpu_cmd_job *job_cmd;
+ int err;
+
+ job_cmd = kzalloc(sizeof(*job_cmd), GFP_KERNEL);
+ if (!job_cmd)
+ return -KVM_ENOMEM;
+
+ job_cmd->msg = (void *)msg;
+
+ err = kvmi_msg_dispatch_vcpu_job(kvmi, job_cmd, queued);
+
+ if (!*queued)
+ kfree(job_cmd);
+
+ return err;
+}
+
static int kvmi_msg_dispatch(struct kvm_introspection *kvmi,
struct kvmi_msg_hdr *msg, bool *queued)
{
int err;
- err = kvmi_msg_dispatch_vm_cmd(kvmi, msg);
+ if (is_vcpu_message(msg->id))
+ err = kvmi_msg_dispatch_vcpu_cmd(kvmi, msg, queued);
+ else
+ err = kvmi_msg_dispatch_vm_cmd(kvmi, msg);
if (err)
kvmi_err(kvmi, "%s: msg id: %u (%s), err: %d\n", __func__,
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