zx_vcpu_create

Summary

Create a VCPU.

Declaration

#include <zircon/syscalls.h>

zx_status_t zx_vcpu_create(zx_handle_t guest,
                           uint32_t options,
                           zx_vaddr_t entry,
                           zx_handle_t* out);

Description

zx_vcpu_create() creates a VCPU within a guest, which allows for execution within the virtual machine. One or more VCPUs may be created per guest, where the number of VCPUs does not need to match the number of physical CPUs on the machine.

entry is the instruction pointer used to indicate where in guest physical memory execution of the VCPU should start.

out is bound to the thread that created it, and all syscalls that operate on it must be called from the same thread, with the exception of zx_vcpu_interrupt().

Only one VCPU may exist on a thread at a time. A thread can create another VCPU after it has closed the existing one.

N.B. VCPU is an abbreviation of virtual CPU.

The following rights will be set on the handle out by default:

ZX_RIGHT_DUPLICATE — out may be duplicated.

ZX_RIGHT_TRANSFER — out may be transferred over a channel.

ZX_RIGHT_EXECUTE — out may have its execution resumed (or begun)

ZX_RIGHT_SIGNAL — out may be interrupted

ZX_RIGHT_READ — out may have its state read

ZX_RIGHT_WRITE — may have its state written

Rights

guest must be of type ZX_OBJ_TYPE_GUEST and have ZX_RIGHT_MANAGE_THREAD.

Return value

zx_vcpu_create() returns ZX_OK on success. On failure, an error value is returned.

Errors

ZX_ERR_ACCESS_DENIED guest does not have the ZX_RIGHT_MANAGE_THREAD right.

ZX_ERR_BAD_HANDLE guest is an invalid handle.

ZX_ERR_BAD_STATE The thread currently has a VCPU. Only one VCPU can be active on a thread at a time.

ZX_ERR_INVALID_ARGS args contains an invalid argument, or out is an invalid pointer, or options is nonzero.

ZX_ERR_NO_MEMORY Failure due to lack of memory. There is no good way for userspace to handle this (unlikely) error. In a future build this error will no longer occur.

ZX_ERR_WRONG_TYPE guest is not a handle to a guest.