[Xen-devel] [PATCH] xen/SandyBridge: reserve pages when integrated graphics

[Xudong Hao <xudong.hao@xxxxxxxxx>]

SNB graphics devices have a bug that prevent them from accessing certain
memory ranges, namely anything below 1M and in the pages listed in the
table.

Xen does not initialize below 1MB to heap, i.e. below 1MB pages don't be
allocated, so it's unnecessary to reserve memory below the 1 MB mark
that has not already been reserved.

So reserve those pages listed in the table at xen boot if set detect a
SNB gfx device on the CPU to avoid GPU hangs.

Signed-off-by: Xudong Hao <xudong.hao@xxxxxxxxx>
---
 xen/arch/x86/mm.c                    | 14 ++++++++++++
 xen/common/page_alloc.c              | 42 +++++++++++++++++++++++++-----------
 xen/drivers/passthrough/vtd/quirks.c |  2 +-
 xen/include/asm-x86/mm.h             |  1 +
 xen/include/asm-x86/pci.h            |  5 +++++
 5 files changed, 50 insertions(+), 14 deletions(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index add93ac..5e706af 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -121,6 +121,7 @@
 #include <xen/trace.h>
 #include <asm/setup.h>
 #include <asm/fixmap.h>
+#include <asm/pci.h>
 
 /* Mapping of the fixmap space needed early. */
 l1_pgentry_t __attribute__ ((__section__ (".bss.page_aligned")))
@@ -5597,6 +5598,19 @@ void arch_dump_shared_mem_info(void)
             mem_sharing_get_nr_saved_mfns());
 }
 
+char *__init get_platform_badpages(void)
+{
+    u32 igd_id;
+    static char __initdata bad_pfns[] = 
+                {"0x20050,0x20110,0x20130,0x20138,0x40004"};
+
+    igd_id = pci_conf_read32(0, 0, 2, 0, 0);
+    if (!IS_SNB_GFX(igd_id))
+        return NULL;
+
+    return bad_pfns;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index 9e9fb15..f818090 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -148,22 +148,10 @@ static void __init bootmem_region_zap(unsigned long s, 
unsigned long e)
     }
 }
 
-void __init init_boot_pages(paddr_t ps, paddr_t pe)
+static void __init remove_bad_pages(const char *p)
 {
     unsigned long bad_spfn, bad_epfn;
-    const char *p;
-
-    ps = round_pgup(ps);
-    pe = round_pgdown(pe);
-    if ( pe <= ps )
-        return;
-
-    first_valid_mfn = min_t(unsigned long, ps >> PAGE_SHIFT, first_valid_mfn);
-
-    bootmem_region_add(ps >> PAGE_SHIFT, pe >> PAGE_SHIFT);
-
     /* Check new pages against the bad-page list. */
-    p = opt_badpage;
     while ( *p != '\0' )
     {
         bad_spfn = simple_strtoul(p, &p, 0);
@@ -186,6 +174,34 @@ void __init init_boot_pages(paddr_t ps, paddr_t pe)
     }
 }
 
+void __init init_boot_pages(paddr_t ps, paddr_t pe)
+{
+    const char *p;
+
+    ps = round_pgup(ps);
+    pe = round_pgdown(pe);
+    if ( pe <= ps )
+        return;
+
+    first_valid_mfn = min_t(unsigned long, ps >> PAGE_SHIFT, first_valid_mfn);
+
+    bootmem_region_add(ps >> PAGE_SHIFT, pe >> PAGE_SHIFT);
+
+#ifdef CONFIG_X86
+    /* 
+     * Here we put platform-specific memory range workarounds, i.e.
+     * memory known to be corrupt or otherwise in need to be reserved on
+     * specific platforms.
+     * We get these certain pages and put them in bad-page list.
+     */
+    p = get_platform_badpages();
+    if ( p )
+        remove_bad_pages(p);
+#endif
+    p = opt_badpage;
+    remove_bad_pages(p);
+}
+
 unsigned long __init alloc_boot_pages(
     unsigned long nr_pfns, unsigned long pfn_align)
 {
diff --git a/xen/drivers/passthrough/vtd/quirks.c 
b/xen/drivers/passthrough/vtd/quirks.c
index d79a155..70d57de 100644
--- a/xen/drivers/passthrough/vtd/quirks.c
+++ b/xen/drivers/passthrough/vtd/quirks.c
@@ -31,6 +31,7 @@
 #include <xen/keyhandler.h>
 #include <asm/msi.h>
 #include <asm/irq.h>
+#include <asm/pci.h>
 #include <mach_apic.h>
 #include "iommu.h"
 #include "dmar.h"
@@ -47,7 +48,6 @@
 #define IS_CTG(id)    (id == 0x2a408086)
 #define IS_ILK(id)    (id == 0x00408086 || id == 0x00448086 || id== 0x00628086 
|| id == 0x006A8086)
 #define IS_CPT(id)    (id == 0x01008086 || id == 0x01048086)
-#define IS_SNB_GFX(id) (id == 0x01068086 || id == 0x01168086 || id == 
0x01268086 || id == 0x01028086 || id == 0x01128086 || id == 0x01228086 || id == 
0x010A8086)
 
 static u32 __read_mostly ioh_id;
 static u32 __initdata igd_id;
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 4f89dae..7af069f 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -322,6 +322,7 @@ int is_iomem_page(unsigned long mfn);
 
 void clear_superpage_mark(struct page_info *page);
 
+char *get_platform_badpages(void);
 /* Per page locks:
  * page_lock() is used for two purposes: pte serialization, and memory sharing.
  *
diff --git a/xen/include/asm-x86/pci.h b/xen/include/asm-x86/pci.h
index 7bcb702..e0598fd 100644
--- a/xen/include/asm-x86/pci.h
+++ b/xen/include/asm-x86/pci.h
@@ -1,6 +1,11 @@
 #ifndef __X86_PCI_H__
 #define __X86_PCI_H__
 
+#define IS_SNB_GFX(id) (id == 0x01068086 || id == 0x01168086 \
+                        || id == 0x01268086 || id == 0x01028086 \
+                        || id == 0x01128086 || id == 0x01228086 \
+                        || id == 0x010A8086 )
+
 struct arch_pci_dev {
     vmask_t used_vectors;
 };
-- 
1.7.12.1


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