From c93c2224e07f77594c5c1acd7e460909da822bb8 Mon Sep 17 00:00:00 2001
From: Chenli Wei <chenli.wei@intel.com>
Date: Thu, 13 Jan 2022 15:48:15 +0800
Subject: [PATCH] hv: alloc multiboot modules memory

Now the multiboot modules memory have not reserve,it's an issue if
these memory alloc and write before VM start.

Incorrect allocation of multiboot modules memory will cause VM lost
data or start faild.

So we find these modules memory range and reserve these memory from
e820 entry.

All these memory will realloc to VM which own them before the vm start.

Tracked-On: #6690
Acked-by: Anthony Xu <anthony.xu@intel.com>
Signed-off-by: Chenli Wei <chenli.wei@intel.com>
---
 hypervisor/arch/x86/e820.c | 62 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/hypervisor/arch/x86/e820.c b/hypervisor/arch/x86/e820.c
index 52b7e7012..fe26ffac4 100644
--- a/hypervisor/arch/x86/e820.c
+++ b/hypervisor/arch/x86/e820.c
@@ -102,6 +102,52 @@ uint64_t e820_alloc_memory(uint64_t size_arg, uint64_t max_addr)
 	return ret;
 }
 
+static void add_e820_entry(uint64_t addr, uint64_t length, uint64_t type)
+{
+	hv_e820_entries_nr++;
+	ASSERT(hv_e820_entries_nr <= E820_MAX_ENTRIES, "e820 entry overflow");
+	hv_e820[hv_e820_entries_nr - 1U].baseaddr = addr;
+	hv_e820[hv_e820_entries_nr - 1U].length = length;
+	hv_e820[hv_e820_entries_nr - 1U].type = type;
+}
+
+static uint64_t e820_alloc_region(uint64_t addr, uint64_t size)
+{
+	uint32_t i;
+	uint64_t entry_start;
+	uint64_t entry_end;
+	uint64_t start_pa = round_page_down(addr);
+	uint64_t end_pa = round_page_up(addr + size);
+	struct e820_entry *entry;
+
+	for (i = 0U; i < hv_e820_entries_nr; i++) {
+		entry = &hv_e820[i];
+		entry_start = entry->baseaddr;
+		entry_end = entry->baseaddr + entry->length;
+
+		/* No need handle in these cases*/
+		if ((entry->type != E820_TYPE_RAM) || (entry_end <= start_pa) || (entry_start >= end_pa)) {
+			continue;
+		}
+
+		if ((entry_start <= start_pa) && (entry_end >= end_pa)) {
+			entry->length = start_pa - entry_start;
+			/*
+			 * .......|start_pa... ....................End_pa|.....
+			 * |entry_start..............................entry_end|
+			 */
+			if (end_pa < entry_end) {
+				add_e820_entry(end_pa, entry_end - end_pa, E820_TYPE_RAM);
+				break;
+			}
+		} else {
+			pr_err("This region not in one entry!");
+		}
+	}
+
+	return addr;
+}
+
 static void init_e820_from_efi_mmap(void)
 {
 	uint32_t i, e820_idx = 0U;
@@ -215,6 +261,19 @@ static void init_e820_from_mmap(struct acrn_boot_info *abi)
 	}
 }
 
+static void alloc_mods_memory(void)
+{
+	uint32_t i;
+	int64_t mod_start = 0UL;
+	struct acrn_boot_info *abi = get_acrn_boot_info();
+
+	for (i = 0; i < abi->mods_count; i++) {
+		mod_start = hva2hpa(abi->mods[i].start);
+		e820_alloc_region(mod_start, abi->mods[i].size);
+	}
+}
+
+
 void init_e820(void)
 {
 	struct acrn_boot_info *abi = get_acrn_boot_info();
@@ -225,6 +284,9 @@ void init_e820(void)
 	} else {
 		init_e820_from_mmap(abi);
 	}
+
+	/* reserve multiboot modules memory */
+	alloc_mods_memory();
 }
 
 uint32_t get_e820_entries_count(void)