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-rw-r--r--arch/arm64/kvm/pkvm.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
new file mode 100644
index 000000000..ebecb7c04
--- /dev/null
+++ b/arch/arm64/kvm/pkvm.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 - Google LLC
+ * Author: Quentin Perret <qperret@google.com>
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/memblock.h>
+#include <linux/sort.h>
+
+#include <asm/kvm_pkvm.h>
+
+#include "hyp_constants.h"
+
+static struct memblock_region *hyp_memory = kvm_nvhe_sym(hyp_memory);
+static unsigned int *hyp_memblock_nr_ptr = &kvm_nvhe_sym(hyp_memblock_nr);
+
+phys_addr_t hyp_mem_base;
+phys_addr_t hyp_mem_size;
+
+static int cmp_hyp_memblock(const void *p1, const void *p2)
+{
+ const struct memblock_region *r1 = p1;
+ const struct memblock_region *r2 = p2;
+
+ return r1->base < r2->base ? -1 : (r1->base > r2->base);
+}
+
+static void __init sort_memblock_regions(void)
+{
+ sort(hyp_memory,
+ *hyp_memblock_nr_ptr,
+ sizeof(struct memblock_region),
+ cmp_hyp_memblock,
+ NULL);
+}
+
+static int __init register_memblock_regions(void)
+{
+ struct memblock_region *reg;
+
+ for_each_mem_region(reg) {
+ if (*hyp_memblock_nr_ptr >= HYP_MEMBLOCK_REGIONS)
+ return -ENOMEM;
+
+ hyp_memory[*hyp_memblock_nr_ptr] = *reg;
+ (*hyp_memblock_nr_ptr)++;
+ }
+ sort_memblock_regions();
+
+ return 0;
+}
+
+void __init kvm_hyp_reserve(void)
+{
+ u64 nr_pages, prev, hyp_mem_pages = 0;
+ int ret;
+
+ if (!is_hyp_mode_available() || is_kernel_in_hyp_mode())
+ return;
+
+ if (kvm_get_mode() != KVM_MODE_PROTECTED)
+ return;
+
+ ret = register_memblock_regions();
+ if (ret) {
+ *hyp_memblock_nr_ptr = 0;
+ kvm_err("Failed to register hyp memblocks: %d\n", ret);
+ return;
+ }
+
+ hyp_mem_pages += hyp_s1_pgtable_pages();
+ hyp_mem_pages += host_s2_pgtable_pages();
+
+ /*
+ * The hyp_vmemmap needs to be backed by pages, but these pages
+ * themselves need to be present in the vmemmap, so compute the number
+ * of pages needed by looking for a fixed point.
+ */
+ nr_pages = 0;
+ do {
+ prev = nr_pages;
+ nr_pages = hyp_mem_pages + prev;
+ nr_pages = DIV_ROUND_UP(nr_pages * STRUCT_HYP_PAGE_SIZE,
+ PAGE_SIZE);
+ nr_pages += __hyp_pgtable_max_pages(nr_pages);
+ } while (nr_pages != prev);
+ hyp_mem_pages += nr_pages;
+
+ /*
+ * Try to allocate a PMD-aligned region to reduce TLB pressure once
+ * this is unmapped from the host stage-2, and fallback to PAGE_SIZE.
+ */
+ hyp_mem_size = hyp_mem_pages << PAGE_SHIFT;
+ hyp_mem_base = memblock_phys_alloc(ALIGN(hyp_mem_size, PMD_SIZE),
+ PMD_SIZE);
+ if (!hyp_mem_base)
+ hyp_mem_base = memblock_phys_alloc(hyp_mem_size, PAGE_SIZE);
+ else
+ hyp_mem_size = ALIGN(hyp_mem_size, PMD_SIZE);
+
+ if (!hyp_mem_base) {
+ kvm_err("Failed to reserve hyp memory\n");
+ return;
+ }
+
+ kvm_info("Reserved %lld MiB at 0x%llx\n", hyp_mem_size >> 20,
+ hyp_mem_base);
+}