Jan Beulich wrote:
Ingo Molnar <[EMAIL PROTECTED]> 14.01.08 16:48 >>>
* Jan Beulich <[EMAIL PROTECTED]> wrote:
Don't rely on kmalloc(PAGE_SIZE) returning PAGE_SIZE aligned memory
(Xen requires GDT *and* LDT to be page-aligned). Using the page
allocator interface also removes the (albeit small) slab allocator
overhead. The same change being done for 64-bits for consistency.
Further, the Xen hypercall interface expects the LDT address to be
virtual, not machine.
coul dyou try this against x86.git as well? We already unified ldt.c as
part of the paravirt patches.
Sure, but it may take me a little while.
I've got the unified version here.
Subject: xen: adjust/fix LDT handling for Xen
From: "Jan Beulich" <[EMAIL PROTECTED]>
Don't rely on kmalloc(PAGE_SIZE) returning PAGE_SIZE aligned memory
(Xen requires GDT *and* LDT to be page-aligned). Using the page
allocator interface also removes the (albeit small) slab allocator
overhead. The same change being done for 64-bits for consistency.
Further, the Xen hypercall interface expects the LDT address to be
virtual, not machine.
[ Adjusted to unified ldt.c - Jeremy ]
Signed-off-by: Jan Beulich <[EMAIL PROTECTED]>
Acked-by: Jeremy Fitzhardinge <[EMAIL PROTECTED]>
Cc: Ingo Molnar <[EMAIL PROTECTED]>
---
arch/x86/kernel/ldt.c | 7 +++----
arch/x86/xen/enlighten.c | 9 +--------
2 files changed, 4 insertions(+), 12 deletions(-)
===================================================================
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -12,7 +12,6 @@
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/vmalloc.h>
-#include <linux/slab.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -40,7 +39,7 @@ static int alloc_ldt(mm_context_t *pc, i
if (mincount * LDT_ENTRY_SIZE > PAGE_SIZE)
newldt = vmalloc(mincount * LDT_ENTRY_SIZE);
else
- newldt = kmalloc(mincount * LDT_ENTRY_SIZE, GFP_KERNEL);
+ newldt = (void *)__get_free_page(GFP_KERNEL);
if (!newldt)
return -ENOMEM;
@@ -78,7 +77,7 @@ static int alloc_ldt(mm_context_t *pc, i
if (oldsize * LDT_ENTRY_SIZE > PAGE_SIZE)
vfree(oldldt);
else
- kfree(oldldt);
+ put_page(virt_to_page(oldldt));
}
return 0;
}
@@ -129,7 +128,7 @@ void destroy_context(struct mm_struct *m
if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
vfree(mm->context.ldt);
else
- kfree(mm->context.ldt);
+ put_page(virt_to_page(mm->context.ldt));
mm->context.size = 0;
}
}
===================================================================
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -275,19 +275,12 @@ static unsigned long xen_store_tr(void)
static void xen_set_ldt(const void *addr, unsigned entries)
{
- unsigned long linear_addr = (unsigned long)addr;
struct mmuext_op *op;
struct multicall_space mcs = xen_mc_entry(sizeof(*op));
op = mcs.args;
op->cmd = MMUEXT_SET_LDT;
- if (linear_addr) {
- /* ldt my be vmalloced, use arbitrary_virt_to_machine */
- xmaddr_t maddr;
- maddr = arbitrary_virt_to_machine((unsigned long)addr);
- linear_addr = (unsigned long)maddr.maddr;
- }
- op->arg1.linear_addr = linear_addr;
+ op->arg1.linear_addr = (unsigned long)addr;
op->arg2.nr_ents = entries;
MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
--
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