* [PATCH] vmnet: stop recieving events when VM is stopped
@ 2023-01-02 1:08 Joelle van Dyne
2023-01-09 9:19 ` Jason Wang
0 siblings, 1 reply; 2+ messages in thread
From: Joelle van Dyne @ 2023-01-02 1:08 UTC (permalink / raw)
To: qemu-devel; +Cc: Joelle van Dyne, Jason Wang, Philippe Mathieu-Daudé
When the VM is stopped using the HMP command "stop", soon the handler will
stop reading from the vmnet interface. This causes a flood of
`VMNET_INTERFACE_PACKETS_AVAILABLE` events to arrive and puts the host CPU
at 100%. We fix this by removing the event handler from vmnet when the VM
is no longer in a running state and restore it when we return to a running
state.
Signed-off-by: Joelle van Dyne <j@getutm.app>
---
net/vmnet_int.h | 2 ++
net/vmnet-common.m | 48 +++++++++++++++++++++++++++++++++-------------
2 files changed, 37 insertions(+), 13 deletions(-)
diff --git a/net/vmnet_int.h b/net/vmnet_int.h
index adf6e8c20d..ffba92108f 100644
--- a/net/vmnet_int.h
+++ b/net/vmnet_int.h
@@ -46,6 +46,8 @@ typedef struct VmnetState {
int packets_send_end_pos;
struct iovec iov_buf[VMNET_PACKETS_LIMIT];
+
+ VMChangeStateEntry *change;
} VmnetState;
const char *vmnet_status_map_str(vmnet_return_t status);
diff --git a/net/vmnet-common.m b/net/vmnet-common.m
index 2cb60b9ddd..2958283485 100644
--- a/net/vmnet-common.m
+++ b/net/vmnet-common.m
@@ -17,6 +17,7 @@
#include "clients.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
+#include "sysemu/runstate.h"
#include <vmnet/vmnet.h>
#include <dispatch/dispatch.h>
@@ -242,6 +243,35 @@ static void vmnet_bufs_init(VmnetState *s)
}
}
+/**
+ * Called on state change to un-register/re-register handlers
+ */
+static void vmnet_vm_state_change_cb(void *opaque, bool running, RunState state)
+{
+ VmnetState *s = opaque;
+
+ if (running) {
+ vmnet_interface_set_event_callback(
+ s->vmnet_if,
+ VMNET_INTERFACE_PACKETS_AVAILABLE,
+ s->if_queue,
+ ^(interface_event_t event_id, xpc_object_t event) {
+ assert(event_id == VMNET_INTERFACE_PACKETS_AVAILABLE);
+ /*
+ * This function is being called from a non qemu thread, so
+ * we only schedule a BH, and do the rest of the io completion
+ * handling from vmnet_send_bh() which runs in a qemu context.
+ */
+ qemu_bh_schedule(s->send_bh);
+ });
+ } else {
+ vmnet_interface_set_event_callback(
+ s->vmnet_if,
+ VMNET_INTERFACE_PACKETS_AVAILABLE,
+ NULL,
+ NULL);
+ }
+}
int vmnet_if_create(NetClientState *nc,
xpc_object_t if_desc,
@@ -329,19 +359,9 @@ int vmnet_if_create(NetClientState *nc,
s->packets_send_current_pos = 0;
s->packets_send_end_pos = 0;
- vmnet_interface_set_event_callback(
- s->vmnet_if,
- VMNET_INTERFACE_PACKETS_AVAILABLE,
- s->if_queue,
- ^(interface_event_t event_id, xpc_object_t event) {
- assert(event_id == VMNET_INTERFACE_PACKETS_AVAILABLE);
- /*
- * This function is being called from a non qemu thread, so
- * we only schedule a BH, and do the rest of the io completion
- * handling from vmnet_send_bh() which runs in a qemu context.
- */
- qemu_bh_schedule(s->send_bh);
- });
+ vmnet_vm_state_change_cb(s, 1, RUN_STATE_RUNNING);
+
+ s->change = qemu_add_vm_change_state_handler(vmnet_vm_state_change_cb, s);
return 0;
}
@@ -356,6 +376,8 @@ void vmnet_cleanup_common(NetClientState *nc)
return;
}
+ vmnet_vm_state_change_cb(s, 0, RUN_STATE_SHUTDOWN);
+ qemu_del_vm_change_state_handler(s->change);
if_stopped_sem = dispatch_semaphore_create(0);
vmnet_stop_interface(
s->vmnet_if,
--
2.28.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] vmnet: stop recieving events when VM is stopped
2023-01-02 1:08 [PATCH] vmnet: stop recieving events when VM is stopped Joelle van Dyne
@ 2023-01-09 9:19 ` Jason Wang
0 siblings, 0 replies; 2+ messages in thread
From: Jason Wang @ 2023-01-09 9:19 UTC (permalink / raw)
To: Joelle van Dyne; +Cc: qemu-devel, Philippe Mathieu-Daudé
On Mon, Jan 2, 2023 at 9:08 AM Joelle van Dyne <j@getutm.app> wrote:
>
> When the VM is stopped using the HMP command "stop", soon the handler will
> stop reading from the vmnet interface. This causes a flood of
> `VMNET_INTERFACE_PACKETS_AVAILABLE` events to arrive and puts the host CPU
> at 100%. We fix this by removing the event handler from vmnet when the VM
> is no longer in a running state and restore it when we return to a running
> state.
>
> Signed-off-by: Joelle van Dyne <j@getutm.app>
Applied.
Thanks
> ---
> net/vmnet_int.h | 2 ++
> net/vmnet-common.m | 48 +++++++++++++++++++++++++++++++++-------------
> 2 files changed, 37 insertions(+), 13 deletions(-)
>
> diff --git a/net/vmnet_int.h b/net/vmnet_int.h
> index adf6e8c20d..ffba92108f 100644
> --- a/net/vmnet_int.h
> +++ b/net/vmnet_int.h
> @@ -46,6 +46,8 @@ typedef struct VmnetState {
> int packets_send_end_pos;
>
> struct iovec iov_buf[VMNET_PACKETS_LIMIT];
> +
> + VMChangeStateEntry *change;
> } VmnetState;
>
> const char *vmnet_status_map_str(vmnet_return_t status);
> diff --git a/net/vmnet-common.m b/net/vmnet-common.m
> index 2cb60b9ddd..2958283485 100644
> --- a/net/vmnet-common.m
> +++ b/net/vmnet-common.m
> @@ -17,6 +17,7 @@
> #include "clients.h"
> #include "qemu/error-report.h"
> #include "qapi/error.h"
> +#include "sysemu/runstate.h"
>
> #include <vmnet/vmnet.h>
> #include <dispatch/dispatch.h>
> @@ -242,6 +243,35 @@ static void vmnet_bufs_init(VmnetState *s)
> }
> }
>
> +/**
> + * Called on state change to un-register/re-register handlers
> + */
> +static void vmnet_vm_state_change_cb(void *opaque, bool running, RunState state)
> +{
> + VmnetState *s = opaque;
> +
> + if (running) {
> + vmnet_interface_set_event_callback(
> + s->vmnet_if,
> + VMNET_INTERFACE_PACKETS_AVAILABLE,
> + s->if_queue,
> + ^(interface_event_t event_id, xpc_object_t event) {
> + assert(event_id == VMNET_INTERFACE_PACKETS_AVAILABLE);
> + /*
> + * This function is being called from a non qemu thread, so
> + * we only schedule a BH, and do the rest of the io completion
> + * handling from vmnet_send_bh() which runs in a qemu context.
> + */
> + qemu_bh_schedule(s->send_bh);
> + });
> + } else {
> + vmnet_interface_set_event_callback(
> + s->vmnet_if,
> + VMNET_INTERFACE_PACKETS_AVAILABLE,
> + NULL,
> + NULL);
> + }
> +}
>
> int vmnet_if_create(NetClientState *nc,
> xpc_object_t if_desc,
> @@ -329,19 +359,9 @@ int vmnet_if_create(NetClientState *nc,
> s->packets_send_current_pos = 0;
> s->packets_send_end_pos = 0;
>
> - vmnet_interface_set_event_callback(
> - s->vmnet_if,
> - VMNET_INTERFACE_PACKETS_AVAILABLE,
> - s->if_queue,
> - ^(interface_event_t event_id, xpc_object_t event) {
> - assert(event_id == VMNET_INTERFACE_PACKETS_AVAILABLE);
> - /*
> - * This function is being called from a non qemu thread, so
> - * we only schedule a BH, and do the rest of the io completion
> - * handling from vmnet_send_bh() which runs in a qemu context.
> - */
> - qemu_bh_schedule(s->send_bh);
> - });
> + vmnet_vm_state_change_cb(s, 1, RUN_STATE_RUNNING);
> +
> + s->change = qemu_add_vm_change_state_handler(vmnet_vm_state_change_cb, s);
>
> return 0;
> }
> @@ -356,6 +376,8 @@ void vmnet_cleanup_common(NetClientState *nc)
> return;
> }
>
> + vmnet_vm_state_change_cb(s, 0, RUN_STATE_SHUTDOWN);
> + qemu_del_vm_change_state_handler(s->change);
> if_stopped_sem = dispatch_semaphore_create(0);
> vmnet_stop_interface(
> s->vmnet_if,
> --
> 2.28.0
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2023-01-09 9:35 UTC | newest]
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2023-01-09 9:19 ` Jason Wang
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