x86: move IDT away from address 0
Address 0 is also used for the SIPI vector (which is probably something worth
changing as well), and now that we call setup_idt very early the SIPI vector
overwrites the first few bytes of the IDT, and in particular the #DE handler.
Fix this for both 32-bit and 64-bit, even though the different form of the
descriptors meant that only 32-bit showed a failure.
Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/x86/cstart.S b/x86/cstart.S
index 5ad70b5..a3c7931 100644
--- a/x86/cstart.S
+++ b/x86/cstart.S
@@ -4,8 +4,6 @@
.globl boot_idt
.global online_cpus
-boot_idt = 0
-
ipi_vector = 0x20
max_cpus = MAX_TEST_CPUS
@@ -30,6 +28,12 @@
i = i + 1
.endr
+boot_idt:
+ .rept 256
+ .quad 0
+ .endr
+end_boot_idt:
+
.globl gdt32
gdt32:
.quad 0
@@ -71,7 +75,7 @@
tss_end:
idt_descr:
- .word 16 * 256 - 1
+ .word end_boot_idt - boot_idt - 1
.long boot_idt
.section .init
diff --git a/x86/cstart64.S b/x86/cstart64.S
index 1ecfbdb..b44d0ae 100644
--- a/x86/cstart64.S
+++ b/x86/cstart64.S
@@ -9,6 +9,8 @@
.globl gdt64_desc
.globl online_cpus
+boot_idt = 0
+
ipi_vector = 0x20
max_cpus = MAX_TEST_CPUS
@@ -51,6 +53,13 @@
.align 4096
+boot_idt:
+ .rept 256
+ .quad 0
+ .quad 0
+ .endr
+end_boot_idt:
+
gdt64_desc:
.word gdt64_end - gdt64 - 1
.quad gdt64
@@ -282,7 +291,7 @@
retq
idt_descr:
- .word 16 * 256 - 1
+ .word end_boot_idt - boot_idt - 1
.quad boot_idt
online_cpus:
