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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-12-22 12:30:10 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-12-22 12:30:10 -0800 |
commit | 9ad95bdacaa3296460fc23e31feaead1d4ffc8b9 (patch) | |
tree | a14e319a5c2abe31aa6542ecccf0f9e9545044ef /drivers/xen | |
parent | fca0e39b2bd2fcfea2027845df28757943d9f561 (diff) | |
parent | b3cf8528bb21febb650a7ecbf080d0647be40b9f (diff) | |
download | linux-stable-9ad95bdacaa3296460fc23e31feaead1d4ffc8b9.tar.gz linux-stable-9ad95bdacaa3296460fc23e31feaead1d4ffc8b9.tar.bz2 linux-stable-9ad95bdacaa3296460fc23e31feaead1d4ffc8b9.zip |
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
Diffstat (limited to 'drivers/xen')
-rw-r--r-- | drivers/xen/balloon.c | 65 |
1 files changed, 56 insertions, 9 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index f77e499afddd..065f0b607373 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -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) @@ -269,13 +284,42 @@ static struct resource *additional_memory_resource(phys_addr_t size) res->name = "System RAM"; res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; - ret = allocate_resource(&iomem_resource, res, - size, 0, -1, - PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL); - if (ret < 0) { - pr_err("Cannot allocate new System RAM resource\n"); - kfree(res); - return NULL; + 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); + if (ret < 0) { + pr_err("Cannot allocate new System RAM resource\n"); + 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 |