[PATCH kvm-unit-tests 0/3] DIV exception tests

[PATCH kvm-unit-tests 0/3] DIV exception tests

[Avi Kivity]

DIV may raise an exception if dividing by zero or causing an overflow.  Test
it.

Avi Kivity (3):
  Support #DE (divide error) exception handlers
  Allow emulation tests to trap exceptions
  Add DIV tests

 config-x86-common.mak |    3 ++-
 x86/emulator.c        |   20 ++++++++++++++++++++
 x86/idt.c             |    8 +++++++-
 3 files changed, 29 insertions(+), 2 deletions(-)

[PATCH kvm-unit-tests 1/3] Support #DE (divide error) exception handlers

[Avi Kivity]

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 x86/idt.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/x86/idt.c b/x86/idt.c
index 590839f..4480833 100644
--- a/x86/idt.c
+++ b/x86/idt.c
@@ -100,6 +100,11 @@ asm (".pushsection .text \n\t"
      "pushq $13 \n\t"
      "jmp handle_exception \n\t"
 
+     "de_fault: \n\t"
+     "pushq $0 \n\t"
+     "pushq $0 \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"
@@ -118,9 +123,10 @@ asm (".pushsection .text \n\t"
 
 void setup_idt(void)
 {
-    extern char ud_fault, gp_fault;
+    extern char ud_fault, gp_fault, de_fault;
 
     lidt(idt, 256);
+    set_idt_entry(&idt[0], &de_fault, 0);
     set_idt_entry(&idt[6], &ud_fault, 0);
     set_idt_entry(&idt[13], &gp_fault, 0);
 }
-- 
1.7.1

[PATCH kvm-unit-tests 2/3] Allow emulation tests to trap exceptions

[Avi Kivity]

Some instructions trap on execution, we need a way to see if they raise an
exception as expected.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 config-x86-common.mak |    3 ++-
 x86/emulator.c        |    2 ++
 2 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/config-x86-common.mak b/config-x86-common.mak
index 19bffd4..0ed13e4 100644
--- a/config-x86-common.mak
+++ b/config-x86-common.mak
@@ -45,7 +45,8 @@ $(TEST_DIR)/vmexit.flat: $(cstart.o) $(TEST_DIR)/vmexit.o
 $(TEST_DIR)/smptest.flat: $(cstart.o) $(TEST_DIR)/smptest.o
  
 $(TEST_DIR)/emulator.flat: $(cstart.o) $(TEST_DIR)/emulator.o \
-			   $(TEST_DIR)/vm.o $(TEST_DIR)/print.o
+			   $(TEST_DIR)/vm.o $(TEST_DIR)/print.o \
+			   $(TEST_DIR)/idt.o
 
 $(TEST_DIR)/port80.flat: $(cstart.o) $(TEST_DIR)/port80.o
 
diff --git a/x86/emulator.c b/x86/emulator.c
index b0d15c0..5d1659f 100644
--- a/x86/emulator.c
+++ b/x86/emulator.c
@@ -1,6 +1,7 @@
 #include "ioram.h"
 #include "vm.h"
 #include "libcflat.h"
+#include "idt.h"
 
 #define memset __builtin_memset
 #define TESTDEV_IO_PORT 0xe0
@@ -582,6 +583,7 @@ int main()
 	unsigned long t1, t2;
 
 	setup_vm();
+	setup_idt();
 	mem = vmap(IORAM_BASE_PHYS, IORAM_LEN);
 
 	// test mov reg, r/m and mov r/m, reg
-- 
1.7.1

[PATCH kvm-unit-tests 3/3] Add DIV tests

[Avi Kivity]

Test divide-by-zero and normal cases.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 x86/emulator.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/x86/emulator.c b/x86/emulator.c
index 5d1659f..845e7a0 100644
--- a/x86/emulator.c
+++ b/x86/emulator.c
@@ -577,6 +577,23 @@ static void test_imul(ulong *mem)
     report("imul rax, mem, imm", a == 0x1D950BDE1D950BC8L);
 }
 
+static void test_div(long *mem)
+{
+    long a, d;
+    u8 ex = 1;
+
+    *mem = 0; a = 1; d = 2;
+    asm (ASM_TRY("1f") "divq %3; movb $0, %2; 1:"
+	 : "+a"(a), "+d"(d), "+q"(ex) : "m"(*mem));
+    report("divq (fault)", a == 1 && d == 2 && ex);
+
+    *mem = 987654321098765UL; a = 123456789012345UL; d = 123456789012345UL;
+    asm (ASM_TRY("1f") "divq %3; movb $0, %2; 1:"
+	 : "+a"(a), "+d"(d), "+q"(ex) : "m"(*mem));
+    report("divq (1)",
+	   a == 0x1ffffffb1b963b33ul && d == 0x273ba4384ede2ul && !ex);
+}
+
 int main()
 {
 	void *mem;
@@ -614,6 +631,7 @@ int main()
 	test_btc(mem);
 	test_bsfbsr(mem);
 	test_imul(mem);
+	test_div(mem);
 
 	printf("\nSUMMARY: %d tests, %d failures\n", tests, fails);
 	return fails ? 1 : 0;
-- 
1.7.1

Re: [PATCH kvm-unit-tests 0/3] DIV exception tests

[Marcelo Tosatti]

On Tue, Aug 24, 2010 at 02:01:08PM +0300, Avi Kivity wrote:
> DIV may raise an exception if dividing by zero or causing an overflow.  Test
> it.
> 
> Avi Kivity (3):
>   Support #DE (divide error) exception handlers
>   Allow emulation tests to trap exceptions
>   Add DIV tests
> 
>  config-x86-common.mak |    3 ++-
>  x86/emulator.c        |   20 ++++++++++++++++++++
>  x86/idt.c             |    8 +++++++-
>  3 files changed, 29 insertions(+), 2 deletions(-)

Applied, thanks.