Re: [PATCH v2 10/23] xen/arm: compile and run xenbus

Konrad Rzeszutek Wilk
2012-08-07T18:31:43Z

On Mon, Aug 06, 2012 at 03:27:13PM +0100, Stefano Stabellini wrote:
> bind_evtchn_to_irqhandler can legitimately return 0 (irq 0): it is not
> an error.
>
> If Linux is running as an HVM domain and is running as Dom0, use
> xenstored_local_init to initialize the xenstore page and event channel.
>
> Changes in v2:
>
> - refactor xenbus_init.

Thank you. Lets also CC our friend at NSA who has been doing some work
in that area. Daniel are you OK with this change - will it still make
PV initial domain with with the MiniOS XenBus driver?

Thanks.
>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
> drivers/xen/xenbus/xenbus_comms.c | 2 +-
> drivers/xen/xenbus/xenbus_probe.c | 62 +++++++++++++++++++++++++-----------
> drivers/xen/xenbus/xenbus_xs.c | 1 +
> 3 files changed, 45 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c
> index 52fe7ad..c5aa55c 100644
> --- a/drivers/xen/xenbus/xenbus_comms.c
> +++ b/drivers/xen/xenbus/xenbus_comms.c
> @@ -224,7 +224,7 @@ int xb_init_comms(void)
> int err;
> err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting,
> 0, "xenbus", &xb_waitq);
> - if (err <= 0) {
> + if (err < 0) {
> printk(KERN_ERR "XENBUS request irq failed %i\n", err);
> return err;
> }

> diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
> index b793723..a67ccc0 100644
> --- a/drivers/xen/xenbus/xenbus_probe.c
> +++ b/drivers/xen/xenbus/xenbus_probe.c
> @@ -719,37 +719,61 @@ static int __init xenstored_local_init(void)
> return err;
> }
>
> +enum xenstore_init {
> + UNKNOWN,
> + PV,
> + HVM,
> + LOCAL,
> +};
> static int __init xenbus_init(void)
> {
> int err = 0;
> + enum xenstore_init usage = UNKNOWN;
> + uint64_t v = 0;
>
> if (!xen_domain())
> return -ENODEV;
>
> xenbus_ring_ops_init();
>
> - if (xen_hvm_domain()) {
> - uint64_t v = 0;
> - err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
> - if (err)
> - goto out_error;
> - xen_store_evtchn = (int)v;
> - err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
> - if (err)
> - goto out_error;
> - xen_store_mfn = (unsigned long)v;
> - xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
> - } else {
> - xen_store_evtchn = xen_start_info->store_evtchn;
> - xen_store_mfn = xen_start_info->store_mfn;
> - if (xen_store_evtchn)
> - xenstored_ready = 1;
> - else {
> + if (xen_pv_domain())
> + usage = PV;
> + if (xen_hvm_domain())
> + usage = HVM;
> + if (xen_hvm_domain() && xen_initial_domain())
> + usage = LOCAL;
> + if (xen_pv_domain() && !xen_start_info->store_evtchn)
> + usage = LOCAL;
> + if (xen_pv_domain() && xen_start_info->store_evtchn)
> + xenstored_ready = 1;
> +
> + switch (usage) {
> + case LOCAL:
> err = xenstored_local_init();
> if (err)
> goto out_error;
> - }
> - xen_store_interface = mfn_to_virt(xen_store_mfn);
> + xen_store_interface = mfn_to_virt(xen_store_mfn);
> + break;
> + case PV:
> + xen_store_evtchn = xen_start_info->store_evtchn;
> + xen_store_mfn = xen_start_info->store_mfn;
> + xen_store_interface = mfn_to_virt(xen_store_mfn);
> + break;
> + case HVM:
> + err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
> + if (err)
> + goto out_error;
> + xen_store_evtchn = (int)v;
> + err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
> + if (err)
> + goto out_error;
> + xen_store_mfn = (unsigned long)v;
> + xen_store_interface =
> + ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
> + break;
> + default:
> + pr_warn("Xenstore state unknown\n");
> + break;
> }
>
> /* Initialize the interface to xenstore. */
> diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
> index d1c217b..f7feb3d 100644
> --- a/drivers/xen/xenbus/xenbus_xs.c
> +++ b/drivers/xen/xenbus/xenbus_xs.c
> @@ -44,6 +44,7 @@
> #include <linux/rwsem.h>
> #include <linux/module.h>
> #include <linux/mutex.h>
> +#include <asm/xen/hypervisor.h>
> #include <xen/xenbus.h>
> #include <xen/xen.h>
> #include "xenbus_comms.h"
> --
> 1.7.2.5