---

yaml
---
r: 104445
b: refs/heads/master
c: d6182fb
h: refs/heads/master
i:
  104443: afa42a6
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c24481e9da2c7bc8aafab46e0bc64821244a24a6
+refs/heads/master: d6182fbf04164016cb6540db02eef3d6bdc967c3

trunk/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 +

trunk/arch/x86/xen/mmu.c

@@ -58,6 +58,13 @@
 #include "multicalls.h"
 #include "mmu.h"
 
+/*
+ * Just beyond the highest usermode address.  STACK_TOP_MAX has a
+ * redzone above it, so round it up to a PGD boundary.
+ */
+#define USER_LIMIT	((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK)
+
+
 #define P2M_ENTRIES_PER_PAGE	(PAGE_SIZE / sizeof(unsigned long))
 #define TOP_ENTRIES		(MAX_DOMAIN_PAGES / P2M_ENTRIES_PER_PAGE)
 
@@ -461,17 +468,45 @@ pud_t xen_make_pud(pudval_t pud)
 	return native_make_pud(pud);
 }
 
-void xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
+pgd_t *xen_get_user_pgd(pgd_t *pgd)
 {
-	struct mmu_update u;
+	pgd_t *pgd_page = (pgd_t *)(((unsigned long)pgd) & PAGE_MASK);
+	unsigned offset = pgd - pgd_page;
+	pgd_t *user_ptr = NULL;
 
-	preempt_disable();
+	if (offset < pgd_index(USER_LIMIT)) {
+		struct page *page = virt_to_page(pgd_page);
+		user_ptr = (pgd_t *)page->private;
+		if (user_ptr)
+			user_ptr += offset;
+	}
 
-	xen_mc_batch();
+	return user_ptr;
+}
+
+static void __xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
+{
+	struct mmu_update u;
 
 	u.ptr = virt_to_machine(ptr).maddr;
 	u.val = pgd_val_ma(val);
 	extend_mmu_update(&u);
+}
+
+/*
+ * Raw hypercall-based set_pgd, intended for in early boot before
+ * there's a page structure.  This implies:
+ *  1. The only existing pagetable is the kernel's
+ *  2. It is always pinned
+ *  3. It has no user pagetable attached to it
+ */
+void __init xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
+{
+	preempt_disable();
+
+	xen_mc_batch();
+
+	__xen_set_pgd_hyper(ptr, val);
 
 	xen_mc_issue(PARAVIRT_LAZY_MMU);
 
@@ -480,14 +515,28 @@ void xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
 
 void xen_set_pgd(pgd_t *ptr, pgd_t val)
 {
+	pgd_t *user_ptr = xen_get_user_pgd(ptr);
+
 	/* If page is not pinned, we can just update the entry
 	   directly */
 	if (!page_pinned(ptr)) {
 		*ptr = val;
+		if (user_ptr) {
+			WARN_ON(page_pinned(user_ptr));
+			*user_ptr = val;
+		}
 		return;
 	}
 
-	xen_set_pgd_hyper(ptr, val);
+	/* If it's pinned, then we can at least batch the kernel and
+	   user updates together. */
+	xen_mc_batch();
+
+	__xen_set_pgd_hyper(ptr, val);
+	if (user_ptr)
+		__xen_set_pgd_hyper(user_ptr, val);
+
+	xen_mc_issue(PARAVIRT_LAZY_MMU);
 }
 #endif	/* PAGETABLE_LEVELS == 4 */
 
@@ -526,7 +575,7 @@ static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
 	 * space, which contains the Xen mappings.  On 32-bit these
 	 * will end up making a zero-sized hole and so is a no-op.
 	 */
-	hole_low = pgd_index(STACK_TOP_MAX + PGDIR_SIZE - 1);
+	hole_low = pgd_index(USER_LIMIT);
 	hole_high = pgd_index(PAGE_OFFSET);
 
 	pgdidx_limit = pgd_index(limit);
@@ -670,19 +719,31 @@ void xen_pgd_pin(pgd_t *pgd)
 {
 	xen_mc_batch();
 
-	if (pgd_walk(pgd, pin_page, TASK_SIZE)) {
+	if (pgd_walk(pgd, pin_page, USER_LIMIT)) {
 		/* re-enable interrupts for kmap_flush_unused */
 		xen_mc_issue(0);
 		kmap_flush_unused();
 		xen_mc_batch();
 	}
 
+#ifdef CONFIG_X86_64
+	{
+		pgd_t *user_pgd = xen_get_user_pgd(pgd);
+
+		xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd)));
+
+		if (user_pgd) {
+			pin_page(virt_to_page(user_pgd), PT_PGD);
+			xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(user_pgd)));
+		}
+	}
+#else /* CONFIG_X86_32 */
 #ifdef CONFIG_X86_PAE
 	/* Need to make sure unshared kernel PMD is pinnable */
 	pin_page(virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), PT_PMD);
 #endif
-
 	xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
+#endif /* CONFIG_X86_64 */
 	xen_mc_issue(0);
 }
 
@@ -763,11 +824,23 @@ static void xen_pgd_unpin(pgd_t *pgd)
 
 	xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
 
+#ifdef CONFIG_X86_64
+	{
+		pgd_t *user_pgd = xen_get_user_pgd(pgd);
+
+		if (user_pgd) {
+			xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(user_pgd)));
+			unpin_page(virt_to_page(user_pgd), PT_PGD);
+		}
+	}
+#endif
+
 #ifdef CONFIG_X86_PAE
 	/* Need to make sure unshared kernel PMD is unpinned */
 	pin_page(virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), PT_PMD);
 #endif
-	pgd_walk(pgd, unpin_page, TASK_SIZE);
+
+	pgd_walk(pgd, unpin_page, USER_LIMIT);
 
 	xen_mc_issue(0);
 }

trunk/arch/x86/xen/mmu.h

@@ -51,6 +51,8 @@ void xen_set_pgd(pgd_t *pgdp, pgd_t pgd);
 void xen_set_pgd_hyper(pgd_t *pgdp, pgd_t pgd);
 #endif
 
+pgd_t *xen_get_user_pgd(pgd_t *pgd);
+
 pte_t xen_ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 void  xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
 				  pte_t *ptep, pte_t pte);