Commit 9351f138 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-linus-6.10a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip 

Pull xen updates from Juergen Gross:

 - a small cleanup in the drivers/xen/xenbus Makefile

 - a fix of the Xen xenstore driver to improve connecting to a late
   started Xenstore

 - an enhancement for better support of ballooning in PVH guests

 - a cleanup using try_cmpxchg() instead of open coding it

* tag 'for-linus-6.10a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  drivers/xen: Improve the late XenStore init protocol
  xen/xenbus: Use *-y instead of *-objs in Makefile
  xen/x86: add extra pages to unpopulated-alloc if available
  locking/x86/xen: Use try_cmpxchg() in xen_alloc_p2m_entry()
parents 02c438bb a3607581

arch/x86/xen/enlighten.c

+33 −0
Original line number Diff line number Diff line
@@ -379,3 +379,36 @@ void __init xen_add_extra_mem(unsigned long start_pfn, unsigned long n_pfns) 


	memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));

}



#ifdef CONFIG_XEN_UNPOPULATED_ALLOC

int __init arch_xen_unpopulated_init(struct resource **res)

{

	unsigned int i;



	if (!xen_domain())

		return -ENODEV;



	/* Must be set strictly before calling xen_free_unpopulated_pages(). */

	*res = &iomem_resource;



	/*

	 * Initialize with pages from the extra memory regions (see

	 * arch/x86/xen/setup.c).

	 */

	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {

		unsigned int j;



		for (j = 0; j < xen_extra_mem[i].n_pfns; j++) {

			struct page *pg =

				pfn_to_page(xen_extra_mem[i].start_pfn + j);



			xen_free_unpopulated_pages(1, &pg);

		}



		/* Zero so region is not also added to the balloon driver. */

		xen_extra_mem[i].n_pfns = 0;

	}



	return 0;

}

#endif

arch/x86/xen/p2m.c

+5 −6
Original line number Diff line number Diff line
@@ -555,7 +555,6 @@ int xen_alloc_p2m_entry(unsigned long pfn) 
			/* Separately check the mid mfn level */

			unsigned long missing_mfn;

			unsigned long mid_mfn_mfn;

			unsigned long old_mfn;



			mid_mfn = alloc_p2m_page();

			if (!mid_mfn)
@@ -565,12 +564,12 @@ int xen_alloc_p2m_entry(unsigned long pfn) 


			missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);

			mid_mfn_mfn = virt_to_mfn(mid_mfn);

			old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn);

			if (old_mfn != missing_mfn) {

				free_p2m_page(mid_mfn);

				mid_mfn = mfn_to_virt(old_mfn);

			} else {

			/* try_cmpxchg() updates missing_mfn on failure. */

			if (try_cmpxchg(top_mfn_p, &missing_mfn, mid_mfn_mfn)) {

				p2m_top_mfn_p[topidx] = mid_mfn;

			} else {

				free_p2m_page(mid_mfn);

				mid_mfn = mfn_to_virt(missing_mfn);

			}

		}

	} else {

drivers/xen/xenbus/Makefile

+6 −8
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

obj-y	+= xenbus.o

obj-y	+= xenbus_dev_frontend.o



xenbus-objs =

xenbus-objs += xenbus_client.o

xenbus-objs += xenbus_comms.o

xenbus-objs += xenbus_xs.o

xenbus-objs += xenbus_probe.o

xenbus-y := xenbus_client.o

xenbus-y += xenbus_comms.o

xenbus-y += xenbus_xs.o

xenbus-y += xenbus_probe.o



xenbus-be-objs-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o

xenbus-objs += $(xenbus-be-objs-y)

xenbus-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o



obj-y	+= xenbus_dev_frontend.o

obj-$(CONFIG_XEN_BACKEND) += xenbus_dev_backend.o

obj-$(CONFIG_XEN_XENBUS_FRONTEND) += xenbus_probe_frontend.o

drivers/xen/xenbus/xenbus_probe.c

+23 −13
Original line number Diff line number Diff line
@@ -65,13 +65,17 @@ 
#include "xenbus.h"





static int xs_init_irq;

static int xs_init_irq = -1;

int xen_store_evtchn;

EXPORT_SYMBOL_GPL(xen_store_evtchn);



struct xenstore_domain_interface *xen_store_interface;

EXPORT_SYMBOL_GPL(xen_store_interface);



#define XS_INTERFACE_READY \

	((xen_store_interface != NULL) && \

	 (xen_store_interface->connection == XENSTORE_CONNECTED))



enum xenstore_init xen_store_domain_type;

EXPORT_SYMBOL_GPL(xen_store_domain_type);
@@ -751,7 +755,7 @@ static void xenbus_probe(void) 
{

	xenstored_ready = 1;



	if (!xen_store_interface) {

	if (!xen_store_interface)

		xen_store_interface = memremap(xen_store_gfn << XEN_PAGE_SHIFT,

					       XEN_PAGE_SIZE, MEMREMAP_WB);

	/*
@@ -762,8 +766,8 @@ static void xenbus_probe(void) 
	 * being called and the event channel not being enabled again

	 * afterwards, resulting in missed event notifications.

	 */

	if (xs_init_irq >= 0)

		free_irq(xs_init_irq, &xb_waitq);

	}



	/*

	 * In the HVM case, xenbus_init() deferred its call to
@@ -822,7 +826,7 @@ static int __init xenbus_probe_initcall(void) 
	if (xen_store_domain_type == XS_PV ||

	    (xen_store_domain_type == XS_HVM &&

	     !xs_hvm_defer_init_for_callback() &&

	     xen_store_interface != NULL))

	     XS_INTERFACE_READY))

		xenbus_probe();



	/*
@@ -831,7 +835,7 @@ static int __init xenbus_probe_initcall(void) 
	 * started, then probe.  It will be triggered when communication

	 * starts happening, by waiting on xb_waitq.

	 */

	if (xen_store_domain_type == XS_LOCAL || xen_store_interface == NULL) {

	if (xen_store_domain_type == XS_LOCAL || !XS_INTERFACE_READY) {

		struct task_struct *probe_task;



		probe_task = kthread_run(xenbus_probe_thread, NULL,
@@ -1014,6 +1018,12 @@ static int __init xenbus_init(void) 
			xen_store_interface =

				memremap(xen_store_gfn << XEN_PAGE_SHIFT,

					 XEN_PAGE_SIZE, MEMREMAP_WB);

			if (!xen_store_interface) {

				pr_err("%s: cannot map HVM_PARAM_STORE_PFN=%llx\n",

				       __func__, v);

				err = -EINVAL;

				goto out_error;

			}

			if (xen_store_interface->connection != XENSTORE_CONNECTED)

				wait = true;

		}