[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v3 1/5] hw/xen: Set XenBackendInstance in the XenDevice before realizing it
From: David Woodhouse <dwmw@xxxxxxxxxxxx> This allows a XenDevice implementation to know whether it was created by QEMU, or merely discovered in XenStore after the toolstack created it. This will allow us to create frontend/backend nodes only when we should, rather than unconditionally attempting to overwrite them from a driver domain which doesn't have privileges to do so. As an added benefit, it also means we no longer have to call the xen_backend_set_device() function from the device models immediately after calling qdev_realize_and_unref(). Even though we could make the argument that it's safe to do so, and the pointer to the unreffed device *will* actually still be valid, it still made my skin itch to look at it. Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx> Reviewed-by: Paul Durrant <paul@xxxxxxx> --- hw/block/xen-block.c | 3 +-- hw/char/xen_console.c | 2 +- hw/net/xen_nic.c | 2 +- hw/xen/xen-backend.c | 15 +-------------- hw/xen/xen-bus.c | 4 ++++ include/hw/xen/xen-backend.h | 2 -- include/hw/xen/xen-bus.h | 2 ++ 7 files changed, 10 insertions(+), 20 deletions(-) diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c index 6d64ede94f..c2ac9db4a2 100644 --- a/hw/block/xen-block.c +++ b/hw/block/xen-block.c @@ -1081,13 +1081,12 @@ static void xen_block_device_create(XenBackendInstance *backend, blockdev->iothread = iothread; blockdev->drive = drive; + xendev->backend = backend; if (!qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) { error_prepend(errp, "realization of device %s failed: ", type); goto fail; } - - xen_backend_set_device(backend, xendev); return; fail: diff --git a/hw/char/xen_console.c b/hw/char/xen_console.c index 5cbee2f184..bef8a3a621 100644 --- a/hw/char/xen_console.c +++ b/hw/char/xen_console.c @@ -600,8 +600,8 @@ static void xen_console_device_create(XenBackendInstance *backend, goto fail; } + xendev->backend = backend; if (qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) { - xen_backend_set_device(backend, xendev); goto done; } diff --git a/hw/net/xen_nic.c b/hw/net/xen_nic.c index af4ba3f1e6..afa10c96e8 100644 --- a/hw/net/xen_nic.c +++ b/hw/net/xen_nic.c @@ -627,8 +627,8 @@ static void xen_net_device_create(XenBackendInstance *backend, net->dev = number; memcpy(&net->conf.macaddr, &mac, sizeof(mac)); + xendev->backend = backend; if (qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) { - xen_backend_set_device(backend, xendev); return; } diff --git a/hw/xen/xen-backend.c b/hw/xen/xen-backend.c index b9bf70a9f5..b2e753ebc8 100644 --- a/hw/xen/xen-backend.c +++ b/hw/xen/xen-backend.c @@ -88,19 +88,6 @@ static void xen_backend_list_add(XenBackendInstance *backend) QLIST_INSERT_HEAD(&backend_list, backend, entry); } -static XenBackendInstance *xen_backend_list_find(XenDevice *xendev) -{ - XenBackendInstance *backend; - - QLIST_FOREACH(backend, &backend_list, entry) { - if (backend->xendev == xendev) { - return backend; - } - } - - return NULL; -} - bool xen_backend_exists(const char *type, const char *name) { const XenBackendImpl *impl = xen_backend_table_lookup(type); @@ -170,7 +157,7 @@ XenDevice *xen_backend_get_device(XenBackendInstance *backend) bool xen_backend_try_device_destroy(XenDevice *xendev, Error **errp) { - XenBackendInstance *backend = xen_backend_list_find(xendev); + XenBackendInstance *backend = xendev->backend; const XenBackendImpl *impl; if (!backend) { diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c index 4973e7d9c9..dd0171ab98 100644 --- a/hw/xen/xen-bus.c +++ b/hw/xen/xen-bus.c @@ -1079,6 +1079,10 @@ static void xen_device_realize(DeviceState *dev, Error **errp) } } + if (xendev->backend) { + xen_backend_set_device(xendev->backend, xendev); + } + xendev->exit.notify = xen_device_exit; qemu_add_exit_notifier(&xendev->exit); return; diff --git a/include/hw/xen/xen-backend.h b/include/hw/xen/xen-backend.h index 0f01631ae7..ea080ba7c9 100644 --- a/include/hw/xen/xen-backend.h +++ b/include/hw/xen/xen-backend.h @@ -10,8 +10,6 @@ #include "hw/xen/xen-bus.h" -typedef struct XenBackendInstance XenBackendInstance; - typedef void (*XenBackendDeviceCreate)(XenBackendInstance *backend, QDict *opts, Error **errp); typedef void (*XenBackendDeviceDestroy)(XenBackendInstance *backend, diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h index 334ddd1ff6..7647c4c38e 100644 --- a/include/hw/xen/xen-bus.h +++ b/include/hw/xen/xen-bus.h @@ -14,9 +14,11 @@ #include "qom/object.h" typedef struct XenEventChannel XenEventChannel; +typedef struct XenBackendInstance XenBackendInstance; struct XenDevice { DeviceState qdev; + XenBackendInstance *backend; domid_t frontend_id; char *name; struct qemu_xs_handle *xsh; -- 2.42.0
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