> -----Original Message-----
> From: Jagannathan Raman <jag.ra...@oracle.com>
> Sent: 19 July 2021 21:00
> To: qemu-devel@nongnu.org
> Cc: stefa...@redhat.com; alex.william...@redhat.com;
> elena.ufimts...@oracle.com; John Levon <john.le...@nutanix.com>;
> john.g.john...@oracle.com; Thanos Makatos
> <thanos.maka...@nutanix.com>; Swapnil Ingle
> <swapnil.in...@nutanix.com>; jag.ra...@oracle.com
> Subject: [PATCH RFC server 05/11] vfio-user: run vfio-user context
>
> Setup a separate thread to run the vfio-user context. The thread acts as
> the main loop for the device.
In your "vfio-user: instantiate vfio-user context" patch you create the vfu
context in blocking-mode, so the only way to run device emulation is in a
separate thread.
Were you going to create a separate thread anyway? You can run device emulation
in polling mode therefore you can avoid creating a separate thread, thus saving
resources. Do plan to do that in the future?
>
> Signed-off-by: Elena Ufimtseva <elena.ufimts...@oracle.com>
> Signed-off-by: John G Johnson <john.g.john...@oracle.com>
> Signed-off-by: Jagannathan Raman <jag.ra...@oracle.com>
> ---
> hw/remote/vfio-user-obj.c | 44
> ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 44 insertions(+)
>
> diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
> index e362709..6a2d0f5 100644
> --- a/hw/remote/vfio-user-obj.c
> +++ b/hw/remote/vfio-user-obj.c
> @@ -35,6 +35,7 @@
> #include "trace.h"
> #include "sysemu/runstate.h"
> #include "qemu/notify.h"
> +#include "qemu/thread.h"
> #include "qapi/error.h"
> #include "sysemu/sysemu.h"
> #include "hw/qdev-core.h"
> @@ -66,6 +67,8 @@ struct VfuObject {
> vfu_ctx_t *vfu_ctx;
>
> PCIDevice *pci_dev;
> +
> + QemuThread vfu_ctx_thread;
> };
>
> static void vfu_object_set_socket(Object *obj, const char *str, Error **errp)
> @@ -90,6 +93,44 @@ static void vfu_object_set_devid(Object *obj, const
> char *str, Error **errp)
> trace_vfu_prop("devid", str);
> }
>
> +static void *vfu_object_ctx_run(void *opaque)
> +{
> + VfuObject *o = opaque;
> + int ret;
> +
> + ret = vfu_realize_ctx(o->vfu_ctx);
> + if (ret < 0) {
> + error_setg(&error_abort, "vfu: Failed to realize device %s- %s",
> + o->devid, strerror(errno));
> + return NULL;
> + }
> +
> + ret = vfu_attach_ctx(o->vfu_ctx);
> + if (ret < 0) {
> + error_setg(&error_abort,
> + "vfu: Failed to attach device %s to context - %s",
> + o->devid, strerror(errno));
> + return NULL;
> + }
> +
> + do {
> + ret = vfu_run_ctx(o->vfu_ctx);
> + if (ret < 0) {
> + if (errno == EINTR) {
> + ret = 0;
> + } else if (errno == ENOTCONN) {
> + object_unparent(OBJECT(o));
> + break;
> + } else {
> + error_setg(&error_abort, "vfu: Failed to run device %s - %s",
> + o->devid, strerror(errno));
> + }
> + }
> + } while (ret == 0);
> +
> + return NULL;
> +}
> +
> static void vfu_object_machine_done(Notifier *notifier, void *data)
> {
> VfuObject *o = container_of(notifier, VfuObject, machine_done);
> @@ -125,6 +166,9 @@ static void vfu_object_machine_done(Notifier
> *notifier, void *data)
> pci_get_word(o->pci_dev->config + PCI_DEVICE_ID),
> pci_get_word(o->pci_dev->config +
> PCI_SUBSYSTEM_VENDOR_ID),
> pci_get_word(o->pci_dev->config + PCI_SUBSYSTEM_ID));
> +
> + qemu_thread_create(&o->vfu_ctx_thread, "VFU ctx runner",
> vfu_object_ctx_run,
> + o, QEMU_THREAD_JOINABLE);
> }
>
> static void vfu_object_init(Object *obj)
> --
> 1.8.3.1
