diff options
Diffstat (limited to 'drivers/hv/hv_proc.c')
| -rw-r--r-- | drivers/hv/hv_proc.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/hv/hv_proc.c b/drivers/hv/hv_proc.c new file mode 100644 index 000000000000..7d7ecb6f6137 --- /dev/null +++ b/drivers/hv/hv_proc.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/types.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <linux/clockchips.h> +#include <linux/slab.h> +#include <linux/cpuhotplug.h> +#include <linux/minmax.h> +#include <asm/mshyperv.h> + +/* + * See struct hv_deposit_memory. The first u64 is partition ID, the rest + * are GPAs. + */ +#define HV_DEPOSIT_MAX (HV_HYP_PAGE_SIZE / sizeof(u64) - 1) + +/* Deposits exact number of pages. Must be called with interrupts enabled. */ +int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages) +{ + struct page **pages, *page; + int *counts; + int num_allocations; + int i, j, page_count; + int order; + u64 status; + int ret; + u64 base_pfn; + struct hv_deposit_memory *input_page; + unsigned long flags; + + if (num_pages > HV_DEPOSIT_MAX) + return -E2BIG; + if (!num_pages) + return 0; + + /* One buffer for page pointers and counts */ + page = alloc_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + pages = page_address(page); + + counts = kcalloc(HV_DEPOSIT_MAX, sizeof(int), GFP_KERNEL); + if (!counts) { + free_page((unsigned long)pages); + return -ENOMEM; + } + + /* Allocate all the pages before disabling interrupts */ + i = 0; + + while (num_pages) { + /* Find highest order we can actually allocate */ + order = 31 - __builtin_clz(num_pages); + + while (1) { + pages[i] = alloc_pages_node(node, GFP_KERNEL, order); + if (pages[i]) + break; + if (!order) { + ret = -ENOMEM; + num_allocations = i; + goto err_free_allocations; + } + --order; + } + + split_page(pages[i], order); + counts[i] = 1 << order; + num_pages -= counts[i]; + i++; + } + num_allocations = i; + + local_irq_save(flags); + + input_page = *this_cpu_ptr(hyperv_pcpu_input_arg); + + input_page->partition_id = partition_id; + + /* Populate gpa_page_list - these will fit on the input page */ + for (i = 0, page_count = 0; i < num_allocations; ++i) { + base_pfn = page_to_pfn(pages[i]); + for (j = 0; j < counts[i]; ++j, ++page_count) + input_page->gpa_page_list[page_count] = base_pfn + j; + } + status = hv_do_rep_hypercall(HVCALL_DEPOSIT_MEMORY, + page_count, 0, input_page, NULL); + local_irq_restore(flags); + if (!hv_result_success(status)) { + hv_status_err(status, "\n"); + ret = hv_result_to_errno(status); + goto err_free_allocations; + } + + ret = 0; + goto free_buf; + +err_free_allocations: + for (i = 0; i < num_allocations; ++i) { + base_pfn = page_to_pfn(pages[i]); + for (j = 0; j < counts[i]; ++j) + __free_page(pfn_to_page(base_pfn + j)); + } + +free_buf: + free_page((unsigned long)pages); + kfree(counts); + return ret; +} +EXPORT_SYMBOL_GPL(hv_call_deposit_pages); + +int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id) +{ + struct hv_input_add_logical_processor *input; + struct hv_output_add_logical_processor *output; + u64 status; + unsigned long flags; + int ret = 0; + + /* + * When adding a logical processor, the hypervisor may return + * HV_STATUS_INSUFFICIENT_MEMORY. When that happens, we deposit more + * pages and retry. + */ + do { + local_irq_save(flags); + + input = *this_cpu_ptr(hyperv_pcpu_input_arg); + /* We don't do anything with the output right now */ + output = *this_cpu_ptr(hyperv_pcpu_output_arg); + + input->lp_index = lp_index; + input->apic_id = apic_id; + input->proximity_domain_info = hv_numa_node_to_pxm_info(node); + status = hv_do_hypercall(HVCALL_ADD_LOGICAL_PROCESSOR, + input, output); + local_irq_restore(flags); + + if (hv_result(status) != HV_STATUS_INSUFFICIENT_MEMORY) { + if (!hv_result_success(status)) { + hv_status_err(status, "cpu %u apic ID: %u\n", + lp_index, apic_id); + ret = hv_result_to_errno(status); + } + break; + } + ret = hv_call_deposit_pages(node, hv_current_partition_id, 1); + } while (!ret); + + return ret; +} + +int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags) +{ + struct hv_create_vp *input; + u64 status; + unsigned long irq_flags; + int ret = 0; + + /* Root VPs don't seem to need pages deposited */ + if (partition_id != hv_current_partition_id) { + /* The value 90 is empirically determined. It may change. */ + ret = hv_call_deposit_pages(node, partition_id, 90); + if (ret) + return ret; + } + + do { + local_irq_save(irq_flags); + + input = *this_cpu_ptr(hyperv_pcpu_input_arg); + + input->partition_id = partition_id; + input->vp_index = vp_index; + input->flags = flags; + input->subnode_type = HV_SUBNODE_ANY; + input->proximity_domain_info = hv_numa_node_to_pxm_info(node); + status = hv_do_hypercall(HVCALL_CREATE_VP, input, NULL); + local_irq_restore(irq_flags); + + if (hv_result(status) != HV_STATUS_INSUFFICIENT_MEMORY) { + if (!hv_result_success(status)) { + hv_status_err(status, "vcpu: %u, lp: %u\n", + vp_index, flags); + ret = hv_result_to_errno(status); + } + break; + } + ret = hv_call_deposit_pages(node, partition_id, 1); + + } while (!ret); + + return ret; +} +EXPORT_SYMBOL_GPL(hv_call_create_vp); |