diff options
| -rw-r--r-- | arch/arm/xen/enlighten.c | 106 | ||||
| -rw-r--r-- | drivers/xen/Kconfig | 2 |
2 files changed, 107 insertions, 1 deletions
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 49bb6757d031..ec5b082f3de6 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -62,6 +62,7 @@ static __read_mostly unsigned int xen_events_irq; static __read_mostly phys_addr_t xen_grant_frames; #define GRANT_TABLE_INDEX 0 +#define EXT_REGION_INDEX 1 uint32_t xen_start_flags; EXPORT_SYMBOL(xen_start_flags); @@ -303,6 +304,111 @@ static void __init xen_acpi_guest_init(void) #endif } +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC +/* + * A type-less specific Xen resource which contains extended regions + * (unused regions of guest physical address space provided by the hypervisor). + */ +static struct resource xen_resource = { + .name = "Xen unused space", +}; + +int __init arch_xen_unpopulated_init(struct resource **res) +{ + struct device_node *np; + struct resource *regs, *tmp_res; + uint64_t min_gpaddr = -1, max_gpaddr = 0; + unsigned int i, nr_reg = 0; + int rc; + + if (!xen_domain()) + return -ENODEV; + + if (!acpi_disabled) + return -ENODEV; + + np = of_find_compatible_node(NULL, NULL, "xen,xen"); + if (WARN_ON(!np)) + return -ENODEV; + + /* Skip region 0 which is reserved for grant table space */ + while (of_get_address(np, nr_reg + EXT_REGION_INDEX, NULL, NULL)) + nr_reg++; + + if (!nr_reg) { + pr_err("No extended regions are found\n"); + return -EINVAL; + } + + regs = kcalloc(nr_reg, sizeof(*regs), GFP_KERNEL); + if (!regs) + return -ENOMEM; + + /* + * Create resource from extended regions provided by the hypervisor to be + * used as unused address space for Xen scratch pages. + */ + for (i = 0; i < nr_reg; i++) { + rc = of_address_to_resource(np, i + EXT_REGION_INDEX, ®s[i]); + if (rc) + goto err; + + if (max_gpaddr < regs[i].end) + max_gpaddr = regs[i].end; + if (min_gpaddr > regs[i].start) + min_gpaddr = regs[i].start; + } + + xen_resource.start = min_gpaddr; + xen_resource.end = max_gpaddr; + + /* + * Mark holes between extended regions as unavailable. The rest of that + * address space will be available for the allocation. + */ + for (i = 1; i < nr_reg; i++) { + resource_size_t start, end; + + /* There is an overlap between regions */ + if (regs[i - 1].end + 1 > regs[i].start) { + rc = -EINVAL; + goto err; + } + + /* There is no hole between regions */ + if (regs[i - 1].end + 1 == regs[i].start) + continue; + + start = regs[i - 1].end + 1; + end = regs[i].start - 1; + + tmp_res = kzalloc(sizeof(*tmp_res), GFP_KERNEL); + if (!tmp_res) { + rc = -ENOMEM; + goto err; + } + + tmp_res->name = "Unavailable space"; + tmp_res->start = start; + tmp_res->end = end; + + rc = insert_resource(&xen_resource, tmp_res); + if (rc) { + pr_err("Cannot insert resource %pR (%d)\n", tmp_res, rc); + kfree(tmp_res); + goto err; + } + } + + *res = &xen_resource; + +err: + kfree(regs); + + return rc; +} +#endif + static void __init xen_dt_guest_init(void) { struct device_node *xen_node; diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 33e941e40082..120d32f164ac 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -327,7 +327,7 @@ config XEN_FRONT_PGDIR_SHBUF config XEN_UNPOPULATED_ALLOC bool "Use unpopulated memory ranges for guest mappings" - depends on X86 && ZONE_DEVICE + depends on ZONE_DEVICE default XEN_BACKEND || XEN_GNTDEV || XEN_DOM0 help Use unpopulated memory ranges in order to create mappings for guest |