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Date: Fri, 09 Mar 2007 14:12:18 +1100
From: Rusty Russell <rusty@...tcorp.com.au>
To: Andrew Morton <akpm@...l.org>
Cc: Andi Kleen <ak@....de>,
lkml - Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH 3/9] lguest: cleanup: allocate separate pages for switcher
code
We don't need physically-contiguous pages for the hypervisor, since we
use map_vm_area anyway.
Two other related cleanups: pass the number of pages to
init_pagetables() so we can remove the constant from the header, and
call populate_hypervisor_pte_page() on each page as we allocate it,
rather than as a separate loop.
Signed-off-by: Rusty Russell <rusty@...tcorp.com.au>
diff -r 9fea34a28460 arch/i386/lguest/core.c
--- a/arch/i386/lguest/core.c Thu Mar 08 16:09:00 2007 +1100
+++ b/arch/i386/lguest/core.c Thu Mar 08 16:21:42 2007 +1100
@@ -24,17 +24,21 @@ static char __initdata hypervisor_blob[]
#include "hypervisor-blob.c"
};
-#define MAX_LGUEST_GUESTS \
- (((PAGE_SIZE << HYPERVISOR_PAGE_ORDER) - sizeof(hypervisor_blob)) \
+/* 64k ought to be enough for anybody! */
+#define HYPERVISOR_PAGES (65536 / PAGE_SIZE)
+
+#define MAX_LGUEST_GUESTS \
+ (((HYPERVISOR_PAGES * PAGE_SIZE) - sizeof(hypervisor_blob)) \
/ sizeof(struct lguest_state))
static struct vm_struct *hypervisor_vma;
+/* Pages for hypervisor itself */
+static struct page *hype_page[HYPERVISOR_PAGES];
static int cpu_had_pge;
static struct {
unsigned long offset;
unsigned short segment;
} lguest_entry __attribute_used__;
-struct page *hype_pages; /* Contiguous pages. */
struct lguest lguests[MAX_LGUEST_GUESTS];
DEFINE_MUTEX(lguest_lock);
@@ -58,15 +62,19 @@ struct lguest_state *__lguest_states(voi
static __init int map_hypervisor(void)
{
- unsigned int i;
- int err;
- struct page *pages[HYPERVISOR_PAGES], **pagep = pages;
-
- hype_pages = alloc_pages(GFP_KERNEL|__GFP_ZERO, HYPERVISOR_PAGE_ORDER);
- if (!hype_pages)
- return -ENOMEM;
-
- hypervisor_vma = __get_vm_area(PAGE_SIZE << HYPERVISOR_PAGE_ORDER,
+ int i, err;
+ struct page **pagep = hype_page;
+
+ for (i = 0; i < ARRAY_SIZE(hype_page); i++) {
+ unsigned long addr = get_zeroed_page(GFP_KERNEL);
+ if (!addr) {
+ err = -ENOMEM;
+ goto free_some_pages;
+ }
+ hype_page[i] = virt_to_page(addr);
+ }
+
+ hypervisor_vma = __get_vm_area(ARRAY_SIZE(hype_page) * PAGE_SIZE,
VM_ALLOC, HYPE_ADDR, VMALLOC_END);
if (!hypervisor_vma) {
err = -ENOMEM;
@@ -74,9 +82,6 @@ static __init int map_hypervisor(void)
goto free_pages;
}
- for (i = 0; i < HYPERVISOR_PAGES; i++)
- pages[i] = hype_pages + i;
-
err = map_vm_area(hypervisor_vma, PAGE_KERNEL, &pagep);
if (err) {
printk("lguest: map_vm_area failed: %i\n", err);
@@ -100,14 +105,20 @@ free_vma:
free_vma:
vunmap(hypervisor_vma->addr);
free_pages:
- __free_pages(hype_pages, HYPERVISOR_PAGE_ORDER);
+ i = ARRAY_SIZE(hype_page);
+free_some_pages:
+ for (--i; i >= 0; i--)
+ __free_pages(hype_page[i], 0);
return err;
}
static __exit void unmap_hypervisor(void)
{
+ unsigned int i;
+
vunmap(hypervisor_vma->addr);
- __free_pages(hype_pages, HYPERVISOR_PAGE_ORDER);
+ for (i = 0; i < ARRAY_SIZE(hype_page); i++)
+ __free_pages(hype_page[i], 0);
}
/* IN/OUT insns: enough to get us past boot-time probing. */
@@ -390,7 +401,7 @@ static int __init init(void)
if (err)
return err;
- err = init_pagetables(hype_pages);
+ err = init_pagetables(hype_page, HYPERVISOR_PAGES);
if (err) {
unmap_hypervisor();
return err;
diff -r 9fea34a28460 arch/i386/lguest/lg.h
--- a/arch/i386/lguest/lg.h Thu Mar 08 16:09:00 2007 +1100
+++ b/arch/i386/lguest/lg.h Thu Mar 08 16:21:42 2007 +1100
@@ -2,9 +2,6 @@
#define _LGUEST_H
#include <asm/desc.h>
-/* 64k ought to be enough for anybody! */
-#define HYPERVISOR_PAGE_ORDER (16 - PAGE_SHIFT)
-#define HYPERVISOR_PAGES (1 << HYPERVISOR_PAGE_ORDER)
#define GDT_ENTRY_LGUEST_CS 10
#define GDT_ENTRY_LGUEST_DS 11
@@ -43,7 +40,7 @@ struct lguest_regs
};
__exit void free_pagetables(void);
-__init int init_pagetables(struct page *hype_pages);
+__init int init_pagetables(struct page **hype_page, int pages);
/* Full 4G segment descriptors, suitable for CS and DS. */
#define FULL_EXEC_SEGMENT ((struct desc_struct){0x0000ffff, 0x00cf9b00})
@@ -122,7 +119,6 @@ struct lguest
struct host_trap interrupt[LGUEST_IRQS];
};
-extern struct page *hype_pages; /* Contiguous pages. */
extern struct lguest lguests[];
extern struct mutex lguest_lock;
diff -r 9fea34a28460 arch/i386/lguest/page_tables.c
--- a/arch/i386/lguest/page_tables.c Thu Mar 08 16:09:00 2007 +1100
+++ b/arch/i386/lguest/page_tables.c Thu Mar 08 16:24:56 2007 +1100
@@ -328,9 +328,23 @@ static void free_hypervisor_pte_pages(vo
free_page((long)hypervisor_pte_page(i));
}
-static __init int alloc_hypervisor_pte_pages(void)
+static __init void populate_hypervisor_pte_page(int cpu,
+ struct page *hype_page[],
+ int pages)
{
int i;
+ u32 *pte = hypervisor_pte_page(cpu);
+
+ for (i = 0; i < pages; i++) {
+ /* First entry set dynamically in map_trap_page */
+ pte[i+1] = ((page_to_pfn(hype_page[i]) << PAGE_SHIFT)
+ | _PAGE_KERNEL_EXEC);
+ }
+}
+
+__init int init_pagetables(struct page **hype_page, int pages)
+{
+ unsigned int i;
for_each_possible_cpu(i) {
hypervisor_pte_page(i) = (u32 *)get_zeroed_page(GFP_KERNEL);
@@ -338,36 +352,11 @@ static __init int alloc_hypervisor_pte_p
free_hypervisor_pte_pages();
return -ENOMEM;
}
+ populate_hypervisor_pte_page(i, hype_page, pages);
}
return 0;
}
-static __init void populate_hypervisor_pte_page(int cpu)
-{
- int i;
- u32 *pte = hypervisor_pte_page(cpu);
-
- for (i = 0; i < HYPERVISOR_PAGES; i++) {
- /* First entry set dynamically in map_trap_page */
- pte[i+1] = ((page_to_pfn(&hype_pages[i]) << PAGE_SHIFT)
- | _PAGE_KERNEL_EXEC);
- }
-}
-
-__init int init_pagetables(struct page hype_pages[])
-{
- int ret;
- unsigned int i;
-
- ret = alloc_hypervisor_pte_pages();
- if (ret)
- return ret;
-
- for_each_possible_cpu(i)
- populate_hypervisor_pte_page(i);
- return 0;
-}
-
__exit void free_pagetables(void)
{
free_hypervisor_pte_pages();
-
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