On 1/15/2022 5:37 AM, Xu, Anthony wrote:

Should we calculate ram size instead of top address?

Now the top address about equal to 4G + RAM SIZE - Low Memory SIZE

Some logic have to get the top address of HPA and it can't replace by
the RAM SIZE.

There might be a big hole in e820.

Anthony

-----Original Message-----
From: Wei, Chenli <chenli.wei@...>
Sent: Thursday, January 13, 2022 11:22 PM
To: Wang, Yu1 <yu1.wang@...>; Xu, Anthony <anthony.xu@...>; acrn-dev@...
Cc: Wei, Chenli <chenli.wei@...>; Chenli Wei <chenli.wei@...>
Subject: [PATCH v2 1/4] hv:calculate hv_e820_top_addr_space dynamically

The e820 module could get the RAM info on run time, but the RAM size
and MAX address was limited by CONFIG_PLATFORM_RAM_SIZE which was
predefind by config tool.

Current solution can't support single binary for different boards or
platforms and the CONFIG_PLATFORM_RAM_SIZE can't matching the RAM size
if user have not update config tools setting after the device changed.

So this patch remove the CONFIG_PLATFORM_RAM_SIZE and calculate end
address of each E820 entry on run time, then find the max address as
the top address.

v1-->v2:
1.code format
2.change the logic of calculate top address.

Tracked-On: #6690
Signed-off-by: Chenli Wei <chenli.wei@...>
---
hypervisor/arch/x86/e820.c | 36 ++++++++++++++++++++------
hypervisor/include/arch/x86/asm/e820.h | 1 +
2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/hypervisor/arch/x86/e820.c b/hypervisor/arch/x86/e820.c
index 52b7e7012..f7eb8279b 100644
--- a/hypervisor/arch/x86/e820.c
+++ b/hypervisor/arch/x86/e820.c
@@ -13,6 +13,7 @@
#include <efi_mmap.h>
#include <logmsg.h>
#include <asm/guest/ept.h>
+#include <util.h>

/*
* e820.c contains the related e820 operations; like HV to get memory info for its MMU setup;
@@ -20,6 +21,8 @@
*/

static uint32_t hv_e820_entries_nr;
+static uint64_t hv_e820_top_addr_space;
+
/* Describe the memory layout the hypervisor uses */
static struct e820_entry hv_e820[E820_MAX_ENTRIES];

@@ -105,7 +108,6 @@ uint64_t e820_alloc_memory(uint64_t size_arg, uint64_t max_addr)
static void init_e820_from_efi_mmap(void)
{
uint32_t i, e820_idx = 0U;
- uint64_t top_addr_space = CONFIG_PLATFORM_RAM_SIZE + PLATFORM_LO_MMIO_SIZE;
const struct efi_memory_desc *efi_mmap_entry = get_efi_mmap_entry();

for (i = 0U; i < get_efi_mmap_entries_count(); i++) {
@@ -116,13 +118,6 @@ static void init_e820_from_efi_mmap(void)

hv_e820[e820_idx].baseaddr = efi_mmap_entry[i].phys_addr;
hv_e820[e820_idx].length = efi_mmap_entry[i].num_pages * PAGE_SIZE;
- if (hv_e820[e820_idx].baseaddr >= top_addr_space) {
- hv_e820[e820_idx].length = 0UL;
- } else {
- if ((hv_e820[e820_idx].baseaddr + hv_e820[e820_idx].length) > top_addr_space) {
- hv_e820[e820_idx].length = top_addr_space - hv_e820[e820_idx].baseaddr;
- }
- }

/* The EFI BOOT Service releated regions need to be set to reserved and avoid being touched by
* hypervisor, because at least below software modules rely on them:
@@ -215,6 +210,24 @@ static void init_e820_from_mmap(struct acrn_boot_info *abi)
}
}

+static void calculate_e820_top_addr(void)
+{
+ uint32_t i;
+
+ for(i = 0; i < hv_e820_entries_nr; i++){
+ dev_dbg(DBG_LEVEL_E820, "hv_e820[%d]:type: 0x%x Base: 0x%016lx length: 0x%016lx", i,
+ hv_e820[i].type, hv_e820[i].baseaddr, hv_e820[i].length);
+
+ if (hv_e820_top_addr_space < hv_e820[i].baseaddr + hv_e820[i].length) {
+ hv_e820_top_addr_space = hv_e820[i].baseaddr + hv_e820[i].length;
+ }
+ }
+ /* if top address less then 4G,we should set 4G as default to contain the Low MMIO */
+ hv_e820_top_addr_space = (hv_e820_top_addr_space > MEM_4G) ? hv_e820_top_addr_space : MEM_4G;
+
+ dev_dbg(DBG_LEVEL_E820, "Top Addr: 0x%016lx ",hv_e820_top_addr_space);
+}
+
void init_e820(void)
{
struct acrn_boot_info *abi = get_acrn_boot_info();
@@ -225,6 +238,13 @@ void init_e820(void)
} else {
init_e820_from_mmap(abi);
}
+
+ calculate_e820_top_addr();
+}
+
+uint64_t get_e820_top_addr(void)
+{
+ return hv_e820_top_addr_space;
}

uint32_t get_e820_entries_count(void)
diff --git a/hypervisor/include/arch/x86/asm/e820.h b/hypervisor/include/arch/x86/asm/e820.h
index 50459c675..23de176e7 100644
--- a/hypervisor/include/arch/x86/asm/e820.h
+++ b/hypervisor/include/arch/x86/asm/e820.h
@@ -40,6 +40,7 @@ void init_e820(void);
uint64_t e820_alloc_memory(uint64_t size_arg, uint64_t max_addr);
/* get total number of the e820 entries */
uint32_t get_e820_entries_count(void);
+uint64_t get_e820_top_addr(void);

/* get the e802 entiries */
const struct e820_entry *get_e820_entry(void);
--
2.17.1