[PATCH kvm-unit-tests v2 0/3] realmode: print to serial port

[PATCH kvm-unit-tests v2 0/3] realmode: print to serial port

[Paolo Bonzini]

The realmode test is compiled in 16-bit mode, hence it uses a
cut-and-pasted version of the mini C library and is still printing
to the old debug port at 0xf1.  Use the serial port instead.

v1->v2: set serial_inited, both in the original and the copied code [Gleb]

Paolo Bonzini (3):
  realmode: restore DF at exit from exec_in_big_real_mode
  io: only initialize serial port once
  realmode: print to serial port

 lib/x86/io.c   |  1 +
 x86/realmode.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 68 insertions(+), 3 deletions(-)

-- 
1.8.1.4

[PATCH kvm-unit-tests v2 1/3] realmode: restore DF at exit from exec_in_big_real_mode

[Paolo Bonzini]

Some tests fail if DF=1.  Restore it directly after executing the test,
do not do it "magically" in print_serial.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 x86/realmode.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/x86/realmode.c b/x86/realmode.c
index 35ace08..71c8a7d 100644
--- a/x86/realmode.c
+++ b/x86/realmode.c
@@ -26,7 +26,7 @@ static void print_serial(const char *buf)
 {
 	unsigned long len = strlen(buf);
 
-	asm volatile ("cld; addr32/rep/outsb" : "+S"(buf), "+c"(len) : "d"(0xf1));
+	asm volatile ("addr32/rep/outsb" : "+S"(buf), "+c"(len) : "d"(0xf1));
 }
 
 static void exit(int code)
@@ -109,6 +109,8 @@ static void exec_in_big_real_mode(struct insn_desc *insn)
 		"pushfl \n\t"
 		"popl %[save]+36 \n\t"
 
+		/* Restore DF for the harness code */
+		"cld\n\t"
 		"xor %[tmp], %[tmp] \n\t"
 		"mov %[tmp], %%gs \n\t"
 		: [tmp]"=&r"(tmp), [save]"+m"(save)
-- 
1.8.1.4

[PATCH kvm-unit-tests v2 2/3] io: only initialize serial port once

[Paolo Bonzini]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 lib/x86/io.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/x86/io.c b/lib/x86/io.c
index 0282888..d3b971e 100644
--- a/lib/x86/io.c
+++ b/lib/x86/io.c
@@ -46,6 +46,7 @@ static void print_serial(const char *buf)
         unsigned long i;
         if (!serial_inited) {
             serial_init();
+            serial_inited = 1;
         }
 
         for (i = 0; i < len; i++) {
-- 
1.8.1.4

[PATCH kvm-unit-tests v2 3/3] realmode: print to serial port

[Paolo Bonzini]

The realmode test is still printing to the old debug port at 0xf1.
Use the serial port instead.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 x86/realmode.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 64 insertions(+), 2 deletions(-)

diff --git a/x86/realmode.c b/x86/realmode.c
index 71c8a7d..981be08 100644
--- a/x86/realmode.c
+++ b/x86/realmode.c
@@ -1,3 +1,7 @@
+#ifndef USE_SERIAL
+#define USE_SERIAL
+#endif
+
 asm(".code16gcc");
 
 typedef unsigned char u8;
@@ -22,16 +26,74 @@ static int strlen(const char *str)
 	return n;
 }
 
+static void outb(u8 data, u16 port)
+{
+	asm volatile("out %0, %1" : : "a"(data), "d"(port));
+}
+
+#ifdef USE_SERIAL
+static int serial_iobase = 0x3f8;
+static int serial_inited = 0;
+
+static u8 inb(u16 port)
+{
+	u8 data;
+	asm volatile("in %1, %0" : "=a"(data) : "d"(port));
+	return data;
+}
+
+static void serial_outb(char ch)
+{
+	u8 lsr;
+
+	do {
+		lsr = inb(serial_iobase + 0x05);
+	} while (!(lsr & 0x20));
+
+	outb(ch, serial_iobase + 0x00);
+}
+
+static void serial_init(void)
+{
+	u8 lcr;
+
+	/* set DLAB */
+	lcr = inb(serial_iobase + 0x03);
+	lcr |= 0x80;
+	outb(lcr, serial_iobase + 0x03);
+
+	/* set baud rate to 115200 */
+	outb(0x01, serial_iobase + 0x00);
+	outb(0x00, serial_iobase + 0x01);
+
+	/* clear DLAB */
+	lcr = inb(serial_iobase + 0x03);
+	lcr &= ~0x80;
+	outb(lcr, serial_iobase + 0x03);
+}
+#endif
+
 static void print_serial(const char *buf)
 {
 	unsigned long len = strlen(buf);
-
+#ifdef USE_SERIAL
+	unsigned long i;
+	if (!serial_inited) {
+	    serial_init();
+	    serial_inited = 1;
+	}
+
+	for (i = 0; i < len; i++) {
+	    serial_outb(buf[i]);
+	}
+#else
 	asm volatile ("addr32/rep/outsb" : "+S"(buf), "+c"(len) : "d"(0xf1));
+#endif
 }
 
 static void exit(int code)
 {
-        asm volatile("out %0, %1" : : "a"(code), "d"((short)0xf4));
+	outb(code, 0xf4);
 }
 
 struct regs {
-- 
1.8.1.4

Re: [PATCH kvm-unit-tests v2 0/3] realmode: print to serial port

[Gleb Natapov]

On Thu, May 09, 2013 at 04:55:02PM +0200, Paolo Bonzini wrote:
> The realmode test is compiled in 16-bit mode, hence it uses a
> cut-and-pasted version of the mini C library and is still printing
> to the old debug port at 0xf1.  Use the serial port instead.
> 
> v1->v2: set serial_inited, both in the original and the copied code [Gleb]
> 
> Paolo Bonzini (3):
>   realmode: restore DF at exit from exec_in_big_real_mode
>   io: only initialize serial port once
>   realmode: print to serial port
> 
Applied, thanks.

>  lib/x86/io.c   |  1 +
>  x86/realmode.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---
>  2 files changed, 68 insertions(+), 3 deletions(-)
> 
> -- 
> 1.8.1.4
> 
> --
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--
			Gleb.