From ad22c3088b0e6354ed517fef38b548525765c05c Mon Sep 17 00:00:00 2001 From: Elena Ufimtseva Date: Fri, 29 Jan 2021 11:46:10 -0500 Subject: multi-process: define MPQemuMsg format and transmission functions Defines MPQemuMsg, which is the message that is sent to the remote process. This message is sent over QIOChannel and is used to command the remote process to perform various tasks. Define transmission functions used by proxy and by remote. Signed-off-by: Jagannathan Raman Signed-off-by: John G Johnson Signed-off-by: Elena Ufimtseva Reviewed-by: Stefan Hajnoczi Message-id: 56ca8bcf95195b2b195b08f6b9565b6d7410bce5.1611938319.git.jag.raman@oracle.com [Replace struct iovec send[2] = {0} with {} to make clang happy as suggested by Peter Maydell . --Stefan] Signed-off-by: Stefan Hajnoczi --- include/hw/remote/mpqemu-link.h | 63 +++++++++++++++++++++++++++++++++++++++++ include/sysemu/iothread.h | 6 ++++ 2 files changed, 69 insertions(+) create mode 100644 include/hw/remote/mpqemu-link.h (limited to 'include') diff --git a/include/hw/remote/mpqemu-link.h b/include/hw/remote/mpqemu-link.h new file mode 100644 index 0000000..cac699c --- /dev/null +++ b/include/hw/remote/mpqemu-link.h @@ -0,0 +1,63 @@ +/* + * Communication channel between QEMU and remote device process + * + * Copyright © 2018, 2021 Oracle and/or its affiliates. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#ifndef MPQEMU_LINK_H +#define MPQEMU_LINK_H + +#include "qom/object.h" +#include "qemu/thread.h" +#include "io/channel.h" + +#define REMOTE_MAX_FDS 8 + +#define MPQEMU_MSG_HDR_SIZE offsetof(MPQemuMsg, data.u64) + +/** + * MPQemuCmd: + * + * MPQemuCmd enum type to specify the command to be executed on the remote + * device. + * + * This uses a private protocol between QEMU and the remote process. vfio-user + * protocol would supersede this in the future. + * + */ +typedef enum { + MPQEMU_CMD_MAX, +} MPQemuCmd; + +/** + * MPQemuMsg: + * @cmd: The remote command + * @size: Size of the data to be shared + * @data: Structured data + * @fds: File descriptors to be shared with remote device + * + * MPQemuMsg Format of the message sent to the remote device from QEMU. + * + */ +typedef struct { + int cmd; + size_t size; + + union { + uint64_t u64; + } data; + + int fds[REMOTE_MAX_FDS]; + int num_fds; +} MPQemuMsg; + +bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp); +bool mpqemu_msg_recv(MPQemuMsg *msg, QIOChannel *ioc, Error **errp); + +bool mpqemu_msg_valid(MPQemuMsg *msg); + +#endif diff --git a/include/sysemu/iothread.h b/include/sysemu/iothread.h index 0c5284d..f177142 100644 --- a/include/sysemu/iothread.h +++ b/include/sysemu/iothread.h @@ -57,4 +57,10 @@ IOThread *iothread_create(const char *id, Error **errp); void iothread_stop(IOThread *iothread); void iothread_destroy(IOThread *iothread); +/* + * Returns true if executing withing IOThread context, + * false otherwise. + */ +bool qemu_in_iothread(void); + #endif /* IOTHREAD_H */ -- cgit v1.1