mini-os: fix number of pages for PVH

When getting the current allocation from Xen, this value includes the
pages allocated in the MMIO area. Fix the highest available RAM page
by subtracting the size of that area.

This requires to read the E820 map before needing this value. Add two
functions returning the current and the maximum number of RAM pages
taking this correction into account.

At the same time add the LAPIC page to the memory map in order to
avoid reusing that PFN for internal purposes.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

diff --git a/arch/x86/mm.c b/arch/x86/mm.c
index 41fcee678ad612c1841cfaddb330172eca389f1c..cfc978f6e7e1be0433c9659f34bb1756c23dd3f9 100644 (file)
--- a/arch/x86/mm.c
+++ b/arch/x86/mm.c
@@ -107,25 +107,20 @@ desc_ptr idt_ptr =
 
 void arch_mm_preinit(void *p)
 {
-    long ret;
-    domid_t domid = DOMID_SELF;
+    unsigned int pages;
     struct hvm_start_info *hsi = p;
 
     if ( hsi->version >= 1 && hsi->memmap_entries > 0 )
         e820_init_memmap((struct hvm_memmap_table_entry *)(unsigned long)
                          hsi->memmap_paddr, hsi->memmap_entries);
+    else
+        e820_init_memmap(NULL, 0);
 
     pt_base = page_table_base;
     first_free_pfn = PFN_UP(to_phys(&_end));
-    ret = HYPERVISOR_memory_op(XENMEM_current_reservation, &domid);
-    if ( ret < 0 )
-    {
-        xprintk("could not get memory size\n");
-        do_exit();
-    }
-
-    last_free_pfn = e820_get_maxpfn(ret);
-    balloon_set_nr_pages(ret, last_free_pfn);
+    pages = e820_get_current_pages();
+    last_free_pfn = e820_get_maxpfn(pages);
+    balloon_set_nr_pages(pages, last_free_pfn);
 }
 #endif
 

diff --git a/balloon.c b/balloon.c
index 9dc77c545cbe5a05e1587f0877f5345b57a94f5c..6ad07644d8b7bc45ac1a30c52151771e9b4567a7 100644 (file)
--- a/balloon.c
+++ b/balloon.c
@@ -44,20 +44,12 @@ void balloon_set_nr_pages(unsigned long pages, unsigned long pfn)
 
 void get_max_pages(void)
 {
-    long ret;
-    domid_t domid = DOMID_SELF;
-
-    ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
-    if ( ret < 0 )
+    nr_max_pages = e820_get_max_pages();
+    if ( nr_max_pages )
     {
-        printk("Could not get maximum pfn\n");
-        return;
+        printk("Maximum memory size: %ld pages\n", nr_max_pages);
+        nr_max_pfn = e820_get_maxpfn(nr_max_pages);
     }
-
-    nr_max_pages = ret;
-    printk("Maximum memory size: %ld pages\n", nr_max_pages);
-
-    nr_max_pfn = e820_get_maxpfn(nr_max_pages);
 }
 
 void mm_alloc_bitmap_remap(void)

diff --git a/e820.c b/e820.c
index ad91e00bad69719d31dba123c19a62c673cf8c9d..49b16878390ffdd54c88f3a651b6022d3dacc1f9 100644 (file)
--- a/e820.c
+++ b/e820.c
@@ -29,6 +29,38 @@
 #include <mini-os/e820.h>
 #include <xen/memory.h>
 
+static unsigned long e820_initial_reserved_pfns;
+
+unsigned long e820_get_current_pages(void)
+{
+    domid_t domid = DOMID_SELF;
+    long ret;
+
+    ret = HYPERVISOR_memory_op(XENMEM_current_reservation, &domid);
+    if ( ret < 0 )
+    {
+        xprintk("could not get memory size\n");
+        do_exit();
+    }
+
+    return ret - e820_initial_reserved_pfns;
+}
+
+unsigned long e820_get_max_pages(void)
+{
+    domid_t domid = DOMID_SELF;
+    long ret;
+
+    ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
+    if ( ret < 0 )
+    {
+        printk("Could not get maximum pfn\n");
+        return 0;
+    }
+
+    return ret - e820_initial_reserved_pfns;
+}
+
 #ifdef CONFIG_E820_TRIVIAL
 struct e820entry e820_map[1] = {
     {
@@ -40,10 +72,6 @@ struct e820entry e820_map[1] = {
 
 unsigned e820_entries = 1;
 
-static void e820_get_memmap(void)
-{
-}
-
 #else
 struct e820entry e820_map[E820_MAX];
 unsigned e820_entries;
@@ -199,6 +227,7 @@ static void e820_sanitize(void)
 {
     int i;
     unsigned long end, start;
+    bool found_lapic = false;
 
     /* Sanitize memory map in current form. */
     e820_process_entries();
@@ -238,8 +267,20 @@ static void e820_sanitize(void)
 
     /* Make remaining temporarily reserved entries permanently reserved. */
     for ( i = 0; i < e820_entries; i++ )
+    {
         if ( e820_map[i].type == E820_TMP_RESERVED )
             e820_map[i].type = E820_RESERVED;
+        if ( e820_map[i].type == E820_RESERVED )
+        {
+            e820_initial_reserved_pfns += e820_map[i].size / PAGE_SIZE;
+            if ( e820_map[i].addr <= LAPIC_ADDRESS &&
+                 e820_map[i].addr + e820_map[i].size > LAPIC_ADDRESS )
+                found_lapic = true;
+        }
+    }
+
+    if ( !found_lapic )
+        e820_insert_entry(LAPIC_ADDRESS, PAGE_SIZE, E820_RESERVED);
 }
 
 static void e820_get_memmap(void)
@@ -264,6 +305,12 @@ void e820_init_memmap(struct hvm_memmap_table_entry *entry, unsigned int num)
 {
     unsigned int i;
 
+    if ( !entry )
+    {
+        e820_get_memmap();
+        return;
+    }
+
     BUILD_BUG_ON(XEN_HVM_MEMMAP_TYPE_RAM != E820_RAM);
     BUILD_BUG_ON(XEN_HVM_MEMMAP_TYPE_RESERVED != E820_RESERVED);
     BUILD_BUG_ON(XEN_HVM_MEMMAP_TYPE_ACPI != E820_ACPI);
@@ -365,9 +412,6 @@ unsigned long e820_get_maxpfn(unsigned long pages)
     int i;
     unsigned long pfns = 0, start = 0;
 
-    if ( !e820_entries )
-        e820_get_memmap();
-
     for ( i = 0; i < e820_entries; i++ )
     {
         if ( e820_map[i].type != E820_RAM )

diff --git a/include/e820.h b/include/e820.h
index 5438a7c8b16c6878608af912f47fe47b759ba46a..ffa15aa95a8344bfc835e19b71a7c90c0dcfbc51 100644 (file)
--- a/include/e820.h
+++ b/include/e820.h
@@ -52,6 +52,8 @@ struct __packed e820entry {
 extern struct e820entry e820_map[];
 extern unsigned e820_entries;
 
+unsigned long e820_get_current_pages(void);
+unsigned long e820_get_max_pages(void);
 unsigned long e820_get_maxpfn(unsigned long pages);
 unsigned long e820_get_max_contig_pages(unsigned long pfn, unsigned long pages);
 #ifndef CONFIG_E820_TRIVIAL

diff --git a/include/x86/arch_mm.h b/include/x86/arch_mm.h
index ffbec5a8073c2388210cfa8e4ef8fd32e0698bd0..a1b975dcf27a3c2d9514826424ae6549c5589bbc 100644 (file)
--- a/include/x86/arch_mm.h
+++ b/include/x86/arch_mm.h
@@ -207,6 +207,8 @@ typedef unsigned long pgentry_t;
 /* to align the pointer to the (next) page boundary */
 #define PAGE_ALIGN(addr)        (((addr)+PAGE_SIZE-1)&PAGE_MASK)
 
+#define LAPIC_ADDRESS  CONST(0xfee00000)
+
 #ifndef __ASSEMBLY__
 /* Definitions for machine and pseudophysical addresses. */
 #ifdef __i386__