Signed-off-by: Sheng Yang <sheng@xxxxxxxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
v3: rearrange printf()s
v2: accurate instruction boundary tests
avoid playing with the stack; use exception tables instead
kvm/test/config-x86-common.mak | 2 +
kvm/test/config-x86_64.mak | 2 +-
kvm/test/flat.lds | 7 ++-
kvm/test/lib/x86/idt.h | 19 +++++
kvm/test/x86/idt.c | 150 ++++++++++++++++++++++++++++++++++++++++
kvm/test/x86/idt_test.c | 49 +++++++++++++
6 files changed, 227 insertions(+), 2 deletions(-)
create mode 100644 kvm/test/lib/x86/idt.h
create mode 100644 kvm/test/x86/idt.c
create mode 100644 kvm/test/x86/idt_test.c
diff --git a/kvm/test/config-x86-common.mak b/kvm/test/config-x86-common.mak
index c97de52..800b635 100644
--- a/kvm/test/config-x86-common.mak
+++ b/kvm/test/config-x86-common.mak
@@ -59,6 +59,8 @@ $(TEST_DIR)/realmode.o: bits = 32
$(TEST_DIR)/msr.flat: $(cstart.o) $(TEST_DIR)/msr.o
+$(TEST_DIR)/idt_test.flat: $(cstart.o) $(TEST_DIR)/idt.o $(TEST_DIR)/idt_test.o
+
arch_clean:
$(RM) $(TEST_DIR)/*.o $(TEST_DIR)/*.flat \
$(TEST_DIR)/.*.d $(TEST_DIR)/lib/.*.d $(TEST_DIR)/lib/*.o
diff --git a/kvm/test/config-x86_64.mak b/kvm/test/config-x86_64.mak
index d8fd2b5..f9cd121 100644
--- a/kvm/test/config-x86_64.mak
+++ b/kvm/test/config-x86_64.mak
@@ -5,6 +5,6 @@ ldarch = elf64-x86-64
CFLAGS += -D__x86_64__
tests = $(TEST_DIR)/access.flat $(TEST_DIR)/apic.flat \
- $(TEST_DIR)/emulator.flat
+ $(TEST_DIR)/emulator.flat $(TEST_DIR)/idt_test.flat
include config-x86-common.mak
diff --git a/kvm/test/flat.lds b/kvm/test/flat.lds
index 4120595..4888f3a 100644
--- a/kvm/test/flat.lds
+++ b/kvm/test/flat.lds
@@ -4,7 +4,12 @@ SECTIONS
stext = .;
.text : { *(.init) *(.text) *(.text.*) }
. = ALIGN(4K);
- .data : { *(.data) }
+ .data : {
+ *(.data)
+ exception_table_start = .;
+ *(.data.ex)
+ exception_table_end = .;
+ }
. = ALIGN(16);
.rodata : { *(.rodata) }
. = ALIGN(16);
diff --git a/kvm/test/lib/x86/idt.h b/kvm/test/lib/x86/idt.h
new file mode 100644
index 0000000..6babcb4
--- /dev/null
+++ b/kvm/test/lib/x86/idt.h
@@ -0,0 +1,19 @@
+#ifndef __IDT_TEST__
+#define __IDT_TEST__
+
+void setup_idt(void);
+
+#define ASM_TRY(catch) \
+ "movl $0, %%gs:4 \n\t" \
+ ".pushsection .data.ex \n\t" \
+ ".quad 1111f, " catch "\n\t" \
+ ".popsection \n\t" \
+ "1111:"
+
+#define UD_VECTOR 6
+#define GP_VECTOR 13
+
+unsigned exception_vector(void);
+unsigned exception_error_code(void);
+
+#endif
diff --git a/kvm/test/x86/idt.c b/kvm/test/x86/idt.c
new file mode 100644
index 0000000..999b3f0
--- /dev/null
+++ b/kvm/test/x86/idt.c
@@ -0,0 +1,150 @@
+#include "idt.h"
+#include "libcflat.h"
+
+typedef struct {
+ unsigned short offset0;
+ unsigned short selector;
+ unsigned short ist : 3;
+ unsigned short : 5;
+ unsigned short type : 4;
+ unsigned short : 1;
+ unsigned short dpl : 2;
+ unsigned short p : 1;
+ unsigned short offset1;
+ unsigned offset2;
+ unsigned reserved;
+} idt_entry_t;
+
+static idt_entry_t idt[256];
+
+typedef struct {
+ unsigned short limit;
+ unsigned long linear_addr;
+} __attribute__((packed)) descriptor_table_t;
+
+void lidt(idt_entry_t *idt, int nentries)
+{
+ descriptor_table_t dt;
+
+ dt.limit = nentries * sizeof(*idt) - 1;
+ dt.linear_addr = (unsigned long)idt;
+ asm volatile ("lidt %0" : : "m"(dt));
+}
+
+unsigned short read_cs()
+{
+ unsigned short r;
+
+ asm volatile ("mov %%cs, %0" : "=r"(r));
+ return r;
+}
+
+void memset(void *a, unsigned char v, int n)
+{
+ unsigned char *x = a;
+
+ while (n--)
+ *x++ = v;
+}
+
+void set_idt_entry(idt_entry_t *e, void *addr, int dpl)
+{
+ memset(e, 0, sizeof *e);
+ e->offset0 = (unsigned long)addr;
+ e->selector = read_cs();
+ e->ist = 0;
+ e->type = 14;
+ e->dpl = dpl;
+ e->p = 1;
+ e->offset1 = (unsigned long)addr >> 16;
+ e->offset2 = (unsigned long)addr >> 32;
+}
+
+struct ex_regs {
+ unsigned long rax, rcx, rdx, rbx;
+ unsigned long dummy, rbp, rsi, rdi;
+ unsigned long r8, r9, r10, r11;
+ unsigned long r12, r13, r14, r15;
+ unsigned long vector;
+ unsigned long error_code;
+ unsigned long rip;
+ unsigned long cs;
+ unsigned long rflags;
+};
+
+struct ex_record {
+ unsigned long rip;
+ unsigned long handler;
+};
+
+extern struct ex_record exception_table_start, exception_table_end;
+
+void do_handle_exception(struct ex_regs *regs)
+{
+ struct ex_record *ex;
+ unsigned ex_val;
+
+ ex_val = regs->vector | (regs->error_code << 16);
+
+ asm("mov %0, %%gs:4" : : "r"(ex_val));
+
+ for (ex = &exception_table_start; ex != &exception_table_end; ++ex) {
+ if (ex->rip == regs->rip) {
+ regs->rip = ex->handler;
+ return;
+ }
+ }
+ printf("unhandled excecption\n");
+ exit(7);
+}
+
+asm (".pushsection .text \n\t"
+ "ud_fault: \n\t"
+ "pushq $0 \n\t"
+ "pushq $6 \n\t"
+ "jmp handle_exception \n\t"
+
+ "gp_fault: \n\t"
+ "pushq $13 \n\t"
+ "jmp handle_exception \n\t"
+
+ "handle_exception: \n\t"
+ "push %r15; push %r14; push %r13; push %r12 \n\t"
+ "push %r11; push %r10; push %r9; push %r8 \n\t"
+ "push %rdi; push %rsi; push %rbp; sub $8, %rsp \n\t"
+ "push %rbx; push %rdx; push %rcx; push %rax \n\t"
+ "mov %rsp, %rdi \n\t"
+ "call do_handle_exception \n\t"
+ "pop %rax; pop %rcx; pop %rdx; pop %rbx \n\t"
+ "add $8, %rsp; pop %rbp; pop %rsi; pop %rdi \n\t"
+ "pop %r8; pop %r9; pop %r10; pop %r11 \n\t"
+ "pop %r12; pop %r13; pop %r14; pop %r15 \n\t"
+ "add $16, %rsp \n\t"
+ "iretq \n\t"
+ ".popsection");
+
+
+void setup_idt(void)
+{
+ extern char ud_fault, gp_fault;
+
+ lidt(idt, 256);
+ set_idt_entry(&idt[6], &ud_fault, 0);
+ set_idt_entry(&idt[13], &gp_fault, 0);
+}
+
+unsigned exception_vector(void)
+{
+ unsigned short vector;
+
+ asm("mov %%gs:4, %0" : "=rm"(vector));
+ return vector;
+}
+
+unsigned exception_error_code(void)
+{
+ unsigned short error_code;
+
+ asm("mov %%gs:6, %0" : "=rm"(error_code));
+ return error_code;
+}
diff --git a/kvm/test/x86/idt_test.c b/kvm/test/x86/idt_test.c
new file mode 100644
index 0000000..59256d4
--- /dev/null
+++ b/kvm/test/x86/idt_test.c
@@ -0,0 +1,49 @@
+#include "libcflat.h"
+#include "idt.h"
+
+int test_ud2(void)
+{
+ asm volatile(ASM_TRY("1f")
+ "ud2 \n\t"
+ "1:" :);
+ return exception_vector();
+}
+
+int test_gp(void)
+{
+ unsigned long tmp;
+
+ asm volatile("mov $0xffffffff, %0 \n\t"
+ ASM_TRY("1f")
+ "mov %0, %%cr4\n\t"
+ "1:"
+ : "=a"(tmp));
+ return exception_vector();
+}
+
+static int nr_fail, nr_test;
+
+static void report(int cond, const char *name)
+{
+ ++nr_test;
+ if (!cond) {
+ ++nr_fail;
+ printf("%s: FAIL\n", name);
+ } else {
+ printf("%s: PASS\n", name);
+ }
+}
+
+int main(void)
+{
+ int r;
+
+ printf("Starting IDT test\n");
+ setup_idt();
+ r = test_gp();
+ report(r == GP_VECTOR, "Testing #GP");
+ r = test_ud2();
+ report(r == UD_VECTOR, "Testing #UD");
+ printf("%d failures of %d tests\n", nr_fail, nr_test);
+ return !nr_fail ? 0 : 1;
+}
--
1.7.1
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