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Commit 9ad95bda authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-linus-4.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip 

Pull xen fixes from Juergen Gross:
 "This contains two fixes for running under Xen:

   - a fix avoiding resource conflicts between adding mmio areas and
     memory hotplug

   - a fix setting NX bits in page table entries copied from Xen when
     running a PV guest"

* tag 'for-linus-4.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: Mark unallocated host memory as UNUSABLE
  x86-64/Xen: eliminate W+X mappings
parents fca0e39b b3cf8528

arch/x86/xen/enlighten.c

+81 −0
Original line number Diff line number Diff line 
#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG

#include <linux/bootmem.h>

#endif

#include <linux/cpu.h>

#include <linux/kexec.h>



#include <xen/features.h>

#include <xen/page.h>

#include <xen/interface/memory.h>



#include <asm/xen/hypercall.h>

#include <asm/xen/hypervisor.h>
@@ -331,3 +335,80 @@ void xen_arch_unregister_cpu(int num) 
}

EXPORT_SYMBOL(xen_arch_unregister_cpu);

#endif



#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG

void __init arch_xen_balloon_init(struct resource *hostmem_resource)

{

	struct xen_memory_map memmap;

	int rc;

	unsigned int i, last_guest_ram;

	phys_addr_t max_addr = PFN_PHYS(max_pfn);

	struct e820_table *xen_e820_table;

	const struct e820_entry *entry;

	struct resource *res;



	if (!xen_initial_domain())

		return;



	xen_e820_table = kmalloc(sizeof(*xen_e820_table), GFP_KERNEL);

	if (!xen_e820_table)

		return;



	memmap.nr_entries = ARRAY_SIZE(xen_e820_table->entries);

	set_xen_guest_handle(memmap.buffer, xen_e820_table->entries);

	rc = HYPERVISOR_memory_op(XENMEM_machine_memory_map, &memmap);

	if (rc) {

		pr_warn("%s: Can't read host e820 (%d)\n", __func__, rc);

		goto out;

	}



	last_guest_ram = 0;

	for (i = 0; i < memmap.nr_entries; i++) {

		if (xen_e820_table->entries[i].addr >= max_addr)

			break;

		if (xen_e820_table->entries[i].type == E820_TYPE_RAM)

			last_guest_ram = i;

	}



	entry = &xen_e820_table->entries[last_guest_ram];

	if (max_addr >= entry->addr + entry->size)

		goto out; /* No unallocated host RAM. */



	hostmem_resource->start = max_addr;

	hostmem_resource->end = entry->addr + entry->size;



	/*

	 * Mark non-RAM regions between the end of dom0 RAM and end of host RAM

	 * as unavailable. The rest of that region can be used for hotplug-based

	 * ballooning.

	 */

	for (; i < memmap.nr_entries; i++) {

		entry = &xen_e820_table->entries[i];



		if (entry->type == E820_TYPE_RAM)

			continue;



		if (entry->addr >= hostmem_resource->end)

			break;



		res = kzalloc(sizeof(*res), GFP_KERNEL);

		if (!res)

			goto out;



		res->name = "Unavailable host RAM";

		res->start = entry->addr;

		res->end = (entry->addr + entry->size < hostmem_resource->end) ?

			    entry->addr + entry->size : hostmem_resource->end;

		rc = insert_resource(hostmem_resource, res);

		if (rc) {

			pr_warn("%s: Can't insert [%llx - %llx) (%d)\n",

				__func__, res->start, res->end, rc);

			kfree(res);

			goto  out;

		}

	}



 out:

	kfree(xen_e820_table);

}

#endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */

arch/x86/xen/enlighten_pv.c

+3 −0
Original line number Diff line number Diff line
@@ -88,6 +88,8 @@ 
#include "multicalls.h"

#include "pmu.h"



#include "../kernel/cpu/cpu.h" /* get_cpu_cap() */



void *xen_initial_gdt;



static int xen_cpu_up_prepare_pv(unsigned int cpu);
@@ -1258,6 +1260,7 @@ asmlinkage __visible void __init xen_start_kernel(void) 
	__userpte_alloc_gfp &= ~__GFP_HIGHMEM;



	/* Work out if we support NX */

	get_cpu_cap(&boot_cpu_data);

	x86_configure_nx();



	/* Get mfn list */

arch/x86/xen/mmu_pv.c

+12 −0
Original line number Diff line number Diff line
@@ -1902,6 +1902,18 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) 
	/* Graft it onto L4[511][510] */

	copy_page(level2_kernel_pgt, l2);



	/*

	 * Zap execute permission from the ident map. Due to the sharing of

	 * L1 entries we need to do this in the L2.

	 */

	if (__supported_pte_mask & _PAGE_NX) {

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

			if (pmd_none(level2_ident_pgt[i]))

				continue;

			level2_ident_pgt[i] = pmd_set_flags(level2_ident_pgt[i], _PAGE_NX);

		}

	}



	/* Copy the initial P->M table mappings if necessary. */

	i = pgd_index(xen_start_info->mfn_list);

	if (i && i < pgd_index(__START_KERNEL_map))

arch/x86/xen/setup.c

+2 −4
Original line number Diff line number Diff line
@@ -808,7 +808,6 @@ char * __init xen_memory_setup(void) 
	addr = xen_e820_table.entries[0].addr;

	size = xen_e820_table.entries[0].size;

	while (i < xen_e820_table.nr_entries) {

		bool discard = false;



		chunk_size = size;

		type = xen_e820_table.entries[i].type;
@@ -824,10 +823,9 @@ char * __init xen_memory_setup(void) 
				xen_add_extra_mem(pfn_s, n_pfns);

				xen_max_p2m_pfn = pfn_s + n_pfns;

			} else

				discard = true;

				type = E820_TYPE_UNUSABLE;

		}



		if (!discard)

		xen_align_and_add_e820_region(addr, chunk_size, type);



		addr += chunk_size;

drivers/xen/balloon.c

+56 −9
Original line number Diff line number Diff line
@@ -257,10 +257,25 @@ static void release_memory_resource(struct resource *resource) 
	kfree(resource);

}



/*

 * Host memory not allocated to dom0. We can use this range for hotplug-based

 * ballooning.

 *

 * It's a type-less resource. Setting IORESOURCE_MEM will make resource

 * management algorithms (arch_remove_reservations()) look into guest e820,

 * which we don't want.

 */

static struct resource hostmem_resource = {

	.name   = "Host RAM",

};



void __attribute__((weak)) __init arch_xen_balloon_init(struct resource *res)

{}



static struct resource *additional_memory_resource(phys_addr_t size)

{

	struct resource *res;

	int ret;

	struct resource *res, *res_hostmem;

	int ret = -ENOMEM;



	res = kzalloc(sizeof(*res), GFP_KERNEL);

	if (!res)
@@ -269,6 +284,34 @@ static struct resource *additional_memory_resource(phys_addr_t size) 
	res->name = "System RAM";

	res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;



	res_hostmem = kzalloc(sizeof(*res), GFP_KERNEL);

	if (res_hostmem) {

		/* Try to grab a range from hostmem */

		res_hostmem->name = "Host memory";

		ret = allocate_resource(&hostmem_resource, res_hostmem,

					size, 0, -1,

					PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);

	}



	if (!ret) {

		/*

		 * Insert this resource into iomem. Because hostmem_resource

		 * tracks portion of guest e820 marked as UNUSABLE noone else

		 * should try to use it.

		 */

		res->start = res_hostmem->start;

		res->end = res_hostmem->end;

		ret = insert_resource(&iomem_resource, res);

		if (ret < 0) {

			pr_err("Can't insert iomem_resource [%llx - %llx]\n",

				res->start, res->end);

			release_memory_resource(res_hostmem);

			res_hostmem = NULL;

			res->start = res->end = 0;

		}

	}



	if (ret) {

		ret = allocate_resource(&iomem_resource, res,

					size, 0, -1,

					PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);
@@ -277,6 +320,7 @@ static struct resource *additional_memory_resource(phys_addr_t size) 
			kfree(res);

			return NULL;

		}

	}



#ifdef CONFIG_SPARSEMEM

	{
@@ -287,6 +331,7 @@ static struct resource *additional_memory_resource(phys_addr_t size) 
			pr_err("New System RAM resource outside addressable RAM (%lu > %lu)\n",

			       pfn, limit);

			release_memory_resource(res);

			release_memory_resource(res_hostmem);

			return NULL;

		}

	}
@@ -765,6 +810,8 @@ static int __init balloon_init(void) 
	set_online_page_callback(&xen_online_page);

	register_memory_notifier(&xen_memory_nb);

	register_sysctl_table(xen_root);



	arch_xen_balloon_init(&hostmem_resource);

#endif



#ifdef CONFIG_XEN_PV