Xen devel - Apr 2012 - [PATCH 0 of 3] Patches for Xen 4.2 (v2).

Patches that were posted last week - with review comments
addressed.

# HG changeset patch
# User Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
# Date 1333398408 14400
# Node ID f1da2ce71ed41d1b74ebe6916ff7710d6579438e
# Parent  1088c8557a46ab28e509bb9482e2a73a21590df8
xen/vga: Add ''vga_delay'' parameter to delay screen output by X
miliseconds per line.

This is useful if you find yourself on machine that has no serial console,
nor any PCI, PCIe to put in a serial card. Nothing really fancy except it allows
to capture the screenshot of the screen using a camera.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff -r 1088c8557a46 -r f1da2ce71ed4 xen/drivers/video/vga.c
--- a/xen/drivers/video/vga.c	Fri Mar 30 21:05:54 2012 +0100
+++ b/xen/drivers/video/vga.c	Mon Apr 02 16:26:48 2012 -0400
@@ -10,7 +10,7 @@
 #include <xen/mm.h>
 #include <xen/vga.h>
 #include <asm/io.h>
-
+#include <xen/delay.h>
 /* Filled in by arch boot code. */
 struct xen_vga_console_info vga_console_info;
 
@@ -49,6 +49,12 @@ void (*vga_puts)(const char *) = vga_noo
 static char __initdata opt_vga[30] = "";
 string_param("vga", opt_vga);
 
+/*
+ * ''vga_delay=miliseconds'' which defines to delay to print a
line
+ * to the screen. 2 is a a good value to get a good screen output.
+ */
+unsigned int __read_mostly vga_delay;
+integer_param("vga_delay", vga_delay);
 /* VGA text-mode definitions. */
 static unsigned int columns, lines;
 #define ATTRIBUTE   7
@@ -135,6 +141,9 @@ static void vga_text_puts(const char *s)
                 ypos = lines - 1;
                 memmove(video, video + 2 * columns, ypos * 2 * columns);
                 memset(video + ypos * 2 * columns, 0, 2 * xpos);
+                if (vga_delay)
+                    mdelay(vga_delay);
+
             }
             xpos = 0;
         }

# HG changeset patch
# User Simon Graham <simon.graham@virtualcomputer.com>
# Date 1333398413 14400
# Node ID caefa03c38366c3e70d937bc95740c5d33c0892a
# Parent  f1da2ce71ed41d1b74ebe6916ff7710d6579438e
xen/pat: After suspend re-write PAT if BIOS changed it.

Certain AMD machines (this was a MSI or GigaBYTE BIOS) after resume
would reset the PAT MSR causing rather weird issues - where
the pages would (say they would be set to WC) would end up with the
wrong type (as they would use the BIOS PAT instead of the one set by
the hypervisor). And in some cases the PAT was stuck and needed
a couple of WRMSRL to actually take.

Signed-off-by: Simon Graham <simon.graham@virtualcomputer.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff -r f1da2ce71ed4 -r caefa03c3836 xen/arch/x86/acpi/power.c
--- a/xen/arch/x86/acpi/power.c	Mon Apr 02 16:26:48 2012 -0400
+++ b/xen/arch/x86/acpi/power.c	Mon Apr 02 16:26:53 2012 -0400
@@ -41,8 +41,27 @@ static DEFINE_SPINLOCK(pm_lock);
 
 struct acpi_sleep_info acpi_sinfo;
 
+static void pat_resume(void);
 void do_suspend_lowlevel(void);
 
+static void
+pat_resume()
+{
+    u64 pat;
+    if (!cpu_has_pat)
+        return;
+
+    rdmsrl(MSR_IA32_CR_PAT, pat);
+    if (pat != host_pat) {
+	printk(KERN_INFO PREFIX "Found PAT MSR: 0x%"PRIx64"\n",
pat);
+	printk(KERN_INFO PREFIX "reseting to 0x%"PRIx64"\n",
host_pat);
+	wrmsrl(MSR_IA32_CR_PAT, host_pat);
+	rdmsrl(MSR_IA32_CR_PAT, pat);
+	if (pat != host_pat)
+	    printk(KERN_WARNING PREFIX "PAT MSR stuck on:
0x%"PRIx64"\n", pat);
+    }
+}
+
 static int device_power_down(void)
 {
     console_suspend();
@@ -194,6 +213,7 @@ static int enter_state(u32 state)
     if ( cpu_has_efer )
         write_efer(read_efer());
 
+    pat_resume();
     device_power_up();
 
     mcheck_init(&boot_cpu_data, 0);

# HG changeset patch
# User Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
# Date 1333398413 14400
# Node ID f789a3effeb6f876b9672e6e64bbd98857f59b61
# Parent  caefa03c38366c3e70d937bc95740c5d33c0892a
xend: Don''t crash due to weird PCI devices

This fixes Red Hat BZ 767742 where a user had some truly
weird PCI devices:

$ lspci -vvv -xxx -s 0000:01:00.0
01:00.0 VGA compatible controller: nVidia Corporation GT218 [NVS 3100M] (rev
ff) (prog-if ff)
 !!! Unknown header type 7f
00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
20: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

And xend would report:

ERROR (pci:1272) Caught ''Looped capability chain:
0000:01:00.0''

This fixes it.

Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff -r caefa03c3836 -r f789a3effeb6 tools/python/xen/util/pci.py
--- a/tools/python/xen/util/pci.py	Mon Apr 02 16:26:53 2012 -0400
+++ b/tools/python/xen/util/pci.py	Mon Apr 02 16:26:53 2012 -0400
@@ -1268,7 +1268,12 @@ class PciDevice:
             pass
 
     def get_info_from_sysfs(self):
-        self.find_capability(0x11)
+        try:
+            self.find_capability(0x11)
+        except PciDeviceParseError, err:
+            log.error("Caught ''%s''" % err)
+            return False
+
         sysfs_mnt = find_sysfs_mnt()
         if sysfs_mnt == None:
             return False

>>> On 02.04.12 at 22:27, Konrad Rzeszutek Wilk
<konrad.wilk@oracle.com> wrote:
> # HG changeset patch
> # User Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> # Date 1333398408 14400
> # Node ID f1da2ce71ed41d1b74ebe6916ff7710d6579438e
> # Parent  1088c8557a46ab28e509bb9482e2a73a21590df8
> xen/vga: Add ''vga_delay'' parameter to delay screen output
by X miliseconds
> per line.
> 
> This is useful if you find yourself on machine that has no serial console,
> nor any PCI, PCIe to put in a serial card. Nothing really fancy except it 
> allows
> to capture the screenshot of the screen using a camera.
> 
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> 
> diff -r 1088c8557a46 -r f1da2ce71ed4 xen/drivers/video/vga.c
> --- a/xen/drivers/video/vga.c	Fri Mar 30 21:05:54 2012 +0100
> +++ b/xen/drivers/video/vga.c	Mon Apr 02 16:26:48 2012 -0400
> @@ -10,7 +10,7 @@
>  #include <xen/mm.h>
>  #include <xen/vga.h>
>  #include <asm/io.h>
> -
> +#include <xen/delay.h>
>  /* Filled in by arch boot code. */
>  struct xen_vga_console_info vga_console_info;
>  
> @@ -49,6 +49,12 @@ void (*vga_puts)(const char *) = vga_noo
>  static char __initdata opt_vga[30] = "";
>  string_param("vga", opt_vga);
>  
> +/*
> + * ''vga_delay=miliseconds'' which defines to delay to
print a line
> + * to the screen. 2 is a a good value to get a good screen output.
Maybe add something like "If you need to use this, do so with care
as it might screw up time handling", since this will suppress the timer
softirq for arbitrary periods of time.
> + */
> +unsigned int __read_mostly vga_delay;
static.
> +integer_param("vga_delay", vga_delay);
Missing blank line.
>  /* VGA text-mode definitions. */
>  static unsigned int columns, lines;
>  #define ATTRIBUTE   7
> @@ -135,6 +141,9 @@ static void vga_text_puts(const char *s)
>                  ypos = lines - 1;
>                  memmove(video, video + 2 * columns, ypos * 2 * columns);
>                  memset(video + ypos * 2 * columns, 0, 2 * xpos);
> +                if (vga_delay)
I don''t think a conditional is needed here.

Jan
> +                    mdelay(vga_delay);
> +
>              }
>              xpos = 0;
>          }

>>> On 02.04.12 at 22:27, Konrad Rzeszutek Wilk
<konrad.wilk@oracle.com> wrote:
> # HG changeset patch
> # User Simon Graham <simon.graham@virtualcomputer.com>
> # Date 1333398413 14400
> # Node ID caefa03c38366c3e70d937bc95740c5d33c0892a
> # Parent  f1da2ce71ed41d1b74ebe6916ff7710d6579438e
> xen/pat: After suspend re-write PAT if BIOS changed it.
> 
> Certain AMD machines (this was a MSI or GigaBYTE BIOS) after resume
> would reset the PAT MSR causing rather weird issues - where
> the pages would (say they would be set to WC) would end up with the
> wrong type (as they would use the BIOS PAT instead of the one set by
> the hypervisor). And in some cases the PAT was stuck and needed
> a couple of WRMSRL to actually take.
But you still fail to explain why the existing PAT resume handling is
insufficient, and without understanding that we shouldn''t be applying
a patch like this.

Jan
> Signed-off-by: Simon Graham <simon.graham@virtualcomputer.com>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> 
> diff -r f1da2ce71ed4 -r caefa03c3836 xen/arch/x86/acpi/power.c
> --- a/xen/arch/x86/acpi/power.c	Mon Apr 02 16:26:48 2012 -0400
> +++ b/xen/arch/x86/acpi/power.c	Mon Apr 02 16:26:53 2012 -0400
> @@ -41,8 +41,27 @@ static DEFINE_SPINLOCK(pm_lock);
>  
>  struct acpi_sleep_info acpi_sinfo;
>  
> +static void pat_resume(void);
>  void do_suspend_lowlevel(void);
>  
> +static void
> +pat_resume()
> +{
> +    u64 pat;
> +    if (!cpu_has_pat)
> +        return;
> +
> +    rdmsrl(MSR_IA32_CR_PAT, pat);
> +    if (pat != host_pat) {
> +	printk(KERN_INFO PREFIX "Found PAT MSR:
0x%"PRIx64"\n", pat);
> +	printk(KERN_INFO PREFIX "reseting to 0x%"PRIx64"\n",
host_pat);
> +	wrmsrl(MSR_IA32_CR_PAT, host_pat);
> +	rdmsrl(MSR_IA32_CR_PAT, pat);
> +	if (pat != host_pat)
> +	    printk(KERN_WARNING PREFIX "PAT MSR stuck on:
0x%"PRIx64"\n", pat);
> +    }
> +}
> +
>  static int device_power_down(void)
>  {
>      console_suspend();
> @@ -194,6 +213,7 @@ static int enter_state(u32 state)
>      if ( cpu_has_efer )
>          write_efer(read_efer());
>  
> +    pat_resume();
>      device_power_up();
>  
>      mcheck_init(&boot_cpu_data, 0);

On Mon, 2012-04-02 at 21:27 +0100, Konrad Rzeszutek Wilk
wrote:
> @@ -49,6 +49,12 @@ void (*vga_puts)(const char *) = vga_noo
>  static char __initdata opt_vga[30] = "";
>  string_param("vga", opt_vga);
>  
> +/*
> + * ''vga_delay=miliseconds'' which defines to delay to
print a line
> + * to the screen. 2 is a a good value to get a good screen output.
> + */
> +unsigned int __read_mostly vga_delay;
> +integer_param("vga_delay", vga_delay);
Please patch docs/misc/xen-command-line.markdown too.

Ian.