Re: [PATCH] xen: Free xenforeignmemory_resource at exit

[Paul Durrant <xadimgnik@xxxxxxxxx>]

On 30/04/2021 17:37, Anthony PERARD wrote:
> From: Anthony PERARD <anthony.perard@xxxxxxxxxx>
>
> Because Coverity complains about it and this is one leak that Valgrind
> reports.
>
> Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
Acked-by: Paul Durrant <paul@xxxxxxx>

> ---
>   hw/i386/xen/xen-hvm.c       | 9 ++++++---
>   include/hw/xen/xen_common.h | 6 ++++++
>   2 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c
> index 7ce672e5a5c3..47ed7772fa39 100644
> --- a/hw/i386/xen/xen-hvm.c
> +++ b/hw/i386/xen/xen-hvm.c
> @@ -109,6 +109,7 @@ typedef struct XenIOState {
>       shared_iopage_t *shared_page;
>       shared_vmport_iopage_t *shared_vmport_page;
>       buffered_iopage_t *buffered_io_page;
> +    xenforeignmemory_resource_handle *fres;
>       QEMUTimer *buffered_io_timer;
>       CPUState **cpu_by_vcpu_id;
>       /* the evtchn port for polling the notification, */
> @@ -1254,6 +1255,9 @@ static void xen_exit_notifier(Notifier *n, void *data)
>       XenIOState *state = container_of(n, XenIOState, exit);
>   
>       xen_destroy_ioreq_server(xen_domid, state->ioservid);
> +    if (state->fres != NULL) {
> +        xenforeignmemory_unmap_resource(xen_fmem, state->fres);
> +    }
>   
>       xenevtchn_close(state->xce_handle);
>       xs_daemon_close(state->xenstore);
> @@ -1321,7 +1325,6 @@ static void xen_wakeup_notifier(Notifier *notifier, void 
> *data)
>   static int xen_map_ioreq_server(XenIOState *state)
>   {
>       void *addr = NULL;
> -    xenforeignmemory_resource_handle *fres;
>       xen_pfn_t ioreq_pfn;
>       xen_pfn_t bufioreq_pfn;
>       evtchn_port_t bufioreq_evtchn;
> @@ -1333,12 +1336,12 @@ static int xen_map_ioreq_server(XenIOState *state)
>        */
>       QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_bufioreq != 0);
>       QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_ioreq(0) != 1);
> -    fres = xenforeignmemory_map_resource(xen_fmem, xen_domid,
> +    state->fres = xenforeignmemory_map_resource(xen_fmem, xen_domid,
>                                            XENMEM_resource_ioreq_server,
>                                            state->ioservid, 0, 2,
>                                            &addr,
>                                            PROT_READ | PROT_WRITE, 0);
> -    if (fres != NULL) {
> +    if (state->fres != NULL) {
>           trace_xen_map_resource_ioreq(state->ioservid, addr);
>           state->buffered_io_page = addr;
>           state->shared_page = addr + TARGET_PAGE_SIZE;
> diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h
> index 82e56339dd7e..a8118b41acfb 100644
> --- a/include/hw/xen/xen_common.h
> +++ b/include/hw/xen/xen_common.h
> @@ -134,6 +134,12 @@ static inline xenforeignmemory_resource_handle 
> *xenforeignmemory_map_resource(
>       return NULL;
>   }
>   
> +static inline int xenforeignmemory_unmap_resource(
> +    xenforeignmemory_handle *fmem, xenforeignmemory_resource_handle *fres)
> +{
> +    return 0;
> +}
> +
>   #endif /* CONFIG_XEN_CTRL_INTERFACE_VERSION < 41100 */
>   
>   #if CONFIG_XEN_CTRL_INTERFACE_VERSION < 41000