TDVF enables lvl5 page table before pass to OS/bootloader
while OVMF enables lvl4 page table.
Check CR4.X86_CR4_LA57 to decide which page table level to use
and initialize our own lvl5 page table if TDX.
Move setup_page_table() before APs startup so that lvl5 page
table is ready for APs. Refactor the common part of setting
cr3 in a wrapper function load_page_table().
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx>
Reviewed-by: Yu Zhang <yu.c.zhang@xxxxxxxxx>
---
lib/x86/setup.c | 22 +++++++++++++++++++---
x86/efi/efistart64.S | 5 +++++
2 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/lib/x86/setup.c b/lib/x86/setup.c
index 7bf5d431f2a8..3a60762494d6 100644
--- a/lib/x86/setup.c
+++ b/lib/x86/setup.c
@@ -231,10 +231,23 @@ static efi_status_t setup_rsdp(efi_bootinfo_t *efi_bootinfo)
}
/* Defined in cstart64.S or efistart64.S */
+extern u8 ptl5;
extern u8 ptl4;
extern u8 ptl3;
extern u8 ptl2;
+static void load_page_table(void)
+{
+ /*
+ * Load new page table based on the level of firmware provided page
+ * table.
+ */
+ if (read_cr4() & X86_CR4_LA57)
+ write_cr3((ulong)&ptl5);
+ else
+ write_cr3((ulong)&ptl4);
+}
+
static void setup_page_table(void)
{
pgd_t *curr_pt;
@@ -247,6 +260,9 @@ static void setup_page_table(void)
/* Set AMD SEV C-Bit for page table entries */
flags |= get_amd_sev_c_bit_mask();
+ /* Level 5 */
+ curr_pt = (pgd_t *)&ptl5;
+ curr_pt[0] = ((phys_addr_t)&ptl4) | flags;
/* Level 4 */
curr_pt = (pgd_t *)&ptl4;
curr_pt[0] = ((phys_addr_t)&ptl3) | flags;
@@ -266,8 +282,7 @@ static void setup_page_table(void)
setup_ghcb_pte((pgd_t *)&ptl4);
}
- /* Load 4-level page table */
- write_cr3((ulong)&ptl4);
+ load_page_table();
}
static void setup_gdt_tss(void)
@@ -297,6 +312,7 @@ void secondary_startup_64(void)
setup_percpu_area();
enable_x2apic();
tdx_ap_init();
+ load_page_table();
while (1)
safe_halt();
@@ -372,9 +388,9 @@ efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo)
if (!is_tdx_guest())
enable_apic();
enable_x2apic();
+ setup_page_table();
aps_init();
smp_init();
- setup_page_table();
return EFI_SUCCESS;
}
diff --git a/x86/efi/efistart64.S b/x86/efi/efistart64.S
index 648d047febb5..ef3db0110c3c 100644
--- a/x86/efi/efistart64.S
+++ b/x86/efi/efistart64.S
@@ -22,6 +22,11 @@ ptl4:
. = . + PAGE_SIZE
.align PAGE_SIZE
+.globl ptl5
+ptl5:
+ . = . + PAGE_SIZE
+.align PAGE_SIZE
+
.globl stacktop
. = . + PAGE_SIZE * MAX_TEST_CPUS
stacktop:
--
2.25.1
