xen64: allocate and manage user pagetables

[linux-2.6-omap-h63xx.git] / arch / x86 / xen / enlighten.c

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index c13698faae54b30e24ec28deda512136bdf7d2db..48f1a7eca8b9fb8dd78fec6b425af1675c3a74cb 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -46,7 +46,6 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 #include <asm/reboot.h>
-#include <asm/pgalloc.h>
 
 #include "xen-ops.h"
 #include "mmu.h"
@@ -711,29 +710,57 @@ static void set_current_cr3(void *v)
        x86_write_percpu(xen_current_cr3, (unsigned long)v);
 }
 
-static void xen_write_cr3(unsigned long cr3)
+static void __xen_write_cr3(bool kernel, unsigned long cr3)
 {
        struct mmuext_op *op;
        struct multicall_space mcs;
-       unsigned long mfn = pfn_to_mfn(PFN_DOWN(cr3));
+       unsigned long mfn;
 
-       BUG_ON(preemptible());
+       if (cr3)
+               mfn = pfn_to_mfn(PFN_DOWN(cr3));
+       else
+               mfn = 0;
 
-       mcs = xen_mc_entry(sizeof(*op));  /* disables interrupts */
+       WARN_ON(mfn == 0 && kernel);
 
-       /* Update while interrupts are disabled, so its atomic with
-          respect to ipis */
-       x86_write_percpu(xen_cr3, cr3);
+       mcs = __xen_mc_entry(sizeof(*op));
 
        op = mcs.args;
-       op->cmd = MMUEXT_NEW_BASEPTR;
+       op->cmd = kernel ? MMUEXT_NEW_BASEPTR : MMUEXT_NEW_USER_BASEPTR;
        op->arg1.mfn = mfn;
 
        MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
 
-       /* Update xen_update_cr3 once the batch has actually
-          been submitted. */
-       xen_mc_callback(set_current_cr3, (void *)cr3);
+       if (kernel) {
+               x86_write_percpu(xen_cr3, cr3);
+
+               /* Update xen_current_cr3 once the batch has actually
+                  been submitted. */
+               xen_mc_callback(set_current_cr3, (void *)cr3);
+       }
+}
+
+static void xen_write_cr3(unsigned long cr3)
+{
+       BUG_ON(preemptible());
+
+       xen_mc_batch();  /* disables interrupts */
+
+       /* Update while interrupts are disabled, so its atomic with
+          respect to ipis */
+       x86_write_percpu(xen_cr3, cr3);
+
+       __xen_write_cr3(true, cr3);
+
+#ifdef CONFIG_X86_64
+       {
+               pgd_t *user_pgd = xen_get_user_pgd(__va(cr3));
+               if (user_pgd)
+                       __xen_write_cr3(false, __pa(user_pgd));
+               else
+                       __xen_write_cr3(false, 0);
+       }
+#endif
 
        xen_mc_issue(PARAVIRT_LAZY_CPU);  /* interrupts restored */
 }
@@ -794,6 +821,40 @@ static void xen_alloc_pmd(struct mm_struct *mm, u32 pfn)
        xen_alloc_ptpage(mm, pfn, PT_PMD);
 }
 
+static int xen_pgd_alloc(struct mm_struct *mm)
+{
+       pgd_t *pgd = mm->pgd;
+       int ret = 0;
+
+       BUG_ON(PagePinned(virt_to_page(pgd)));
+
+#ifdef CONFIG_X86_64
+       {
+               struct page *page = virt_to_page(pgd);
+
+               BUG_ON(page->private != 0);
+
+               page->private = __get_free_page(GFP_KERNEL | __GFP_ZERO);
+               if (page->private == 0)
+                       ret = -ENOMEM;
+
+               BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd))));
+       }
+#endif
+
+       return ret;
+}
+
+static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+#ifdef CONFIG_X86_64
+       pgd_t *user_pgd = xen_get_user_pgd(pgd);
+
+       if (user_pgd)
+               free_page((unsigned long)user_pgd);
+#endif
+}
+
 /* This should never happen until we're OK to use struct page */
 static void xen_release_ptpage(u32 pfn, unsigned level)
 {
@@ -1168,8 +1229,8 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = {
        .pte_update = paravirt_nop,
        .pte_update_defer = paravirt_nop,
 
-       .pgd_alloc = __paravirt_pgd_alloc,
-       .pgd_free = paravirt_nop,
+       .pgd_alloc = xen_pgd_alloc,
+       .pgd_free = xen_pgd_free,
 
        .alloc_pte = xen_alloc_pte_init,
        .release_pte = xen_release_pte_init,
@@ -1480,7 +1541,15 @@ static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pf
 
        /* Switch over */
        pgd = init_level4_pgt;
-       xen_write_cr3(__pa(pgd));
+
+       /*
+        * At this stage there can be no user pgd, and no page
+        * structure to attach it to, so make sure we just set kernel
+        * pgd.
+        */
+       xen_mc_batch();
+       __xen_write_cr3(true, __pa(pgd));
+       xen_mc_issue(PARAVIRT_LAZY_CPU);
 
        reserve_early(__pa(xen_start_info->pt_base),
                      __pa(xen_start_info->pt_base +