bitkeeper revision 1.105.1.8 (3e63781aEVDfQh1rIWk8m6mnaO7HtA)

Merge labyrinth.cl.cam.ac.uk:/usr/groups/xeno/BK/xeno.bk
into labyrinth.cl.cam.ac.uk:/local/scratch/kaf24/bd-xeno

7 files changed, 331 insertions, 1 deletions

diff --git a/xenolinux-2.4.21-pre4-sparse/arch/xeno/Makefile b/xenolinux-2.4.21-pre4-sparse/arch/xeno/Makefile
index 544af84605..557fe98217 100644
--- a/xenolinux-2.4.21-pre4-sparse/arch/xeno/Makefile
+++ b/xenolinux-2.4.21-pre4-sparse/arch/xeno/Makefile
@@ -47,12 +47,14 @@ HEAD := arch/xeno/kernel/head.o arch/xeno/kernel/init_task.o
 SUBDIRS += arch/xeno/kernel arch/xeno/mm arch/xeno/lib
 SUBDIRS += arch/xeno/drivers/console arch/xeno/drivers/network
 SUBDIRS += arch/xeno/drivers/dom0 arch/xeno/drivers/block
+SUBDIRS += arch/xeno/drivers/balloon
 
 CORE_FILES += arch/xeno/kernel/kernel.o arch/xeno/mm/mm.o
 CORE_FILES += arch/xeno/drivers/console/con.o
 CORE_FILES += arch/xeno/drivers/block/blk.o
 CORE_FILES += arch/xeno/drivers/network/net.o
 CORE_FILES += arch/xeno/drivers/dom0/dom0.o
+CORE_FILES += arch/xeno/drivers/balloon/balloon_driver.o
 LIBS := $(TOPDIR)/arch/xeno/lib/lib.a $(LIBS) $(TOPDIR)/arch/xeno/lib/lib.a
 
 arch/xeno/kernel: dummy
@@ -73,6 +75,9 @@ arch/xeno/drivers/block: dummy
 arch/xeno/drivers/dom0: dummy
 	$(MAKE) linuxsubdirs SUBDIRS=arch/xeno/drivers/dom0
 
+arch/xeno/drivers/balloon: dummy
+	$(MAKE) linuxsubdirs SUBDIRS=arch/xeno/drivers/balloon
+
 MAKEBOOT = $(MAKE) -C arch/$(ARCH)/boot
 
 vmlinux: arch/xeno/vmlinux.lds
diff --git a/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/balloon/Makefile b/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/balloon/Makefile
new file mode 100644
index 0000000000..f780a515e0
--- /dev/null
+++ b/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/balloon/Makefile
@@ -0,0 +1,3 @@
+O_TARGET := balloon_driver.o
+obj-y := balloon.o
+include $(TOPDIR)/Rules.make
diff --git a/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/balloon/balloon.c b/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/balloon/balloon.c
new file mode 100644
index 0000000000..abe5884800
--- /dev/null
+++ b/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/balloon/balloon.c
@@ -0,0 +1,275 @@
+/******************************************************************************
+ * balloon.c
+ *
+ * Xeno balloon driver - enables returning/claiming memory to/from xen
+ *
+ * Copyright (c) 2003, B Dragovic
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/proc_fs.h>
+
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/smp_lock.h>
+#include <linux/pagemap.h>
+
+#include <asm/hypervisor.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+#include <asm/tlb.h>
+
+#include "dom_mem_ops.h"
+
+/* USER DEFINES -- THESE SHOULD BE COPIED TO USER-SPACE TOOLS */
+#define USER_INFLATE_BALLOON  1   /* return mem to hypervisor */
+#define USER_DEFLATE_BALLOON  2   /* claim mem from hypervisor */
+typedef struct user_balloon_op {
+    unsigned int  op;
+    unsigned long size;
+} user_balloon_op_t;
+/* END OF USER DEFINE */
+
+/* Dead entry written into ballon-owned entries in the PMT. */
+#define DEAD 0xdeadbeef
+
+#define BALLOON_ENTRY    "balloon"
+extern struct proc_dir_entry *xeno_base;
+
+static struct proc_dir_entry *balloon_pde;
+unsigned long credit;
+
+static inline unsigned long get_ppte(unsigned long addr)
+{
+    unsigned long ppte;
+    pgd_t *pgd; pmd_t *pmd; pte_t *ptep;
+    pgd = pgd_offset_k(addr);
+
+    if ( pgd_none(*pgd) || pgd_bad(*pgd) ) BUG();
+
+    pmd = pmd_offset(pgd, addr);
+    if ( pmd_none(*pmd) || pmd_bad(*pmd) ) BUG();
+
+    ptep = pte_offset(pmd, addr);
+    ppte = (unsigned long)__pa(ptep);
+
+    return ppte;
+}
+
+/* main function for relinquishing bit of memory */
+static unsigned long inflate_balloon(unsigned long num_pages)
+{
+    dom_mem_op_t dom_mem_op;
+    unsigned long *parray;
+    unsigned long *currp;
+    unsigned long ret = 0;
+    unsigned long vaddr;
+    unsigned long i, j;
+
+    parray = (unsigned long *)kmalloc(num_pages *
+                                      sizeof(unsigned long), GFP_KERNEL);
+    currp = parray;
+
+    for ( i = 0; i < num_pages; i++ )
+    {
+        /* try to obtain a free page, has to be done with GFP_ATOMIC
+         * as we do not want to sleep indefinately.
+         */
+        vaddr = __get_free_page(GFP_ATOMIC);
+
+        /* if allocation fails, free all reserved pages */
+        if(!vaddr){
+            printk("Unable to inflate balloon by %ld, only %ld pages free.",
+                   num_pages, i);
+            currp = parray;
+            for(j = 0; j < i; j++){
+                free_page(*currp++);
+            }
+            goto cleanup;
+        }
+
+        *currp++ = vaddr;
+    }
+
+
+    currp = parray;
+    for ( i = 0; i < num_pages; i++ )
+    {
+        queue_l1_entry_update(get_ppte(*currp) | PGREQ_NORMAL, 0);
+        phys_to_machine_mapping[__pa(*currp) >> PAGE_SHIFT] = DEAD;
+        currp++;
+    }
+
+    XENO_flush_page_update_queue();
+
+    dom_mem_op.op = BALLOON_INFLATE_OP;
+    dom_mem_op.u.balloon_inflate.size  = num_pages;
+    dom_mem_op.u.balloon_inflate.pages = parray;
+    if ( (ret = HYPERVISOR_dom_mem_op(&dom_mem_op)) != num_pages )
+    {
+        printk("Unable to deflate balloon, error %lx\n", ret);
+        goto cleanup;
+    }
+
+    credit += num_pages;
+    ret = num_pages;
+
+ cleanup:
+    kfree(parray);
+
+    return ret;
+}
+
+/* install new mem pages obtained by deflate_balloon. function walks 
+ * phys->machine mapping table looking for DEAD entries and populates
+ * them.
+ */
+static unsigned long process_new_pages(unsigned long * parray, 
+                                       unsigned long num)
+{
+    /* currently, this function is rather simplistic as 
+     * it is assumed that domain reclaims only number of 
+     * pages previously released. this is to change soon
+     * and the code to extend page tables etc. will be 
+     * incorporated here.
+     */
+     
+    unsigned long tot_pages = start_info.nr_pages;   
+    unsigned long * curr = parray;
+    unsigned long num_installed;
+    unsigned long i;
+
+    num_installed = 0;
+    for ( i = 0; i < tot_pages; i++ )
+    {
+        if ( phys_to_machine_mapping[i] == DEAD )
+        {
+            phys_to_machine_mapping[i] = *curr;
+            queue_l1_entry_update((i << PAGE_SHIFT) | PGREQ_MPT_UPDATE, i);
+            queue_l1_entry_update(
+                get_ppte((unsigned long)__va(i << PAGE_SHIFT)) | PGREQ_NORMAL, 
+                ((*curr) << PAGE_SHIFT) | L1_PROT);
+
+            *curr = (unsigned long)__va(i << PAGE_SHIFT);
+            curr++;
+            num_installed++;
+        }
+    }
+
+    /* now, this is tricky (and will also change for machine addrs that 
+      * are mapped to not previously released addresses). we free pages
+      * that were allocated by get_free_page (the mappings are different 
+      * now, of course).
+      */
+    curr = parray;
+    for ( i = 0; i < num_installed; i++ )
+    {
+        free_page(*curr);
+        curr++;
+    }
+
+    return num_installed;
+}
+
+static unsigned long deflate_balloon(unsigned long num_pages)
+{
+    dom_mem_op_t dom_mem_op;
+    unsigned long ret;
+    unsigned long * parray;
+
+    if ( num_pages > credit )
+    {
+        printk("Can not allocate more pages than previously released.\n");
+        return -EAGAIN;
+    }
+
+    parray = (unsigned long *)kmalloc(num_pages * sizeof(unsigned long), 
+                                      GFP_KERNEL);
+
+    dom_mem_op.op = BALLOON_DEFLATE_OP;
+    dom_mem_op.u.balloon_deflate.size = num_pages;
+    dom_mem_op.u.balloon_deflate.pages = parray;
+    if((ret = HYPERVISOR_dom_mem_op(&dom_mem_op)) != num_pages){
+        printk("Unable to deflate balloon, error %lx\n", ret);
+        goto cleanup;
+    }
+
+    if((ret = process_new_pages(parray, num_pages)) < num_pages){
+        printk("Unable to deflate balloon by specified %lx pages, only %lx.\n",
+               num_pages, ret);
+        goto cleanup;
+    }
+
+    ret = num_pages;
+
+ cleanup:
+    kfree(parray);
+
+    return ret;
+}
+
+static int balloon_write(struct file *file, const char *buffer,
+                         u_long count, void *data)
+{
+    user_balloon_op_t bop;
+
+    /* Only admin can play with the balloon :) */
+    if ( !capable(CAP_SYS_ADMIN) )
+        return -EPERM;
+
+    if ( copy_from_user(&bop, buffer, sizeof(bop)) )
+        return -EFAULT;
+
+    switch ( bop.op )
+    {
+    case USER_INFLATE_BALLOON:
+        if ( inflate_balloon(bop.size) < bop.size )
+            return -EAGAIN;
+        break;
+        
+    case USER_DEFLATE_BALLOON:
+        deflate_balloon(bop.size);
+        break;
+
+    default:
+        printk("Unknown command to balloon driver.");
+        return -EFAULT;
+    }
+
+    return sizeof(bop);
+}
+
+/*
+ * main balloon driver initialization function.
+ */
+static int __init init_module(void)
+{
+    printk(KERN_ALERT "Starting Xeno Balloon driver\n");
+
+    credit = 0;
+
+    balloon_pde = create_proc_entry(BALLOON_ENTRY, 0600, xeno_base);
+    if ( balloon_pde == NULL )
+    {
+        printk(KERN_ALERT "Unable to create balloon driver proc entry!");
+        return -1;
+    }
+
+    balloon_pde->write_proc = balloon_write;
+
+    return 0;
+}
+
+static void __exit cleanup_module(void)
+{
+}
+
+module_init(init_module);
+module_exit(cleanup_module);
+
+
diff --git a/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/balloon/dom_mem_ops.h b/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/balloon/dom_mem_ops.h
new file mode 100644
index 0000000000..c473f193e7
--- /dev/null
+++ b/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/balloon/dom_mem_ops.h
@@ -0,0 +1,32 @@
+/******************************************************************************
+ * dom_mem_ops.h
+ *
+ * Header file supporting domain related memory operations. N.B. keep in sync
+ * with xen version. 
+ *
+ * Copyright (c) 2003, B Dragovic
+ */
+
+#define L1_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_USER|_PAGE_ACCESSED)
+#define BALLOON_DEFLATE_OP   0
+#define BALLOON_INFLATE_OP   1
+
+typedef struct balloon_deflate_op {
+    unsigned long   size;
+    unsigned long   * pages;
+} balloon_def_op_t;
+
+typedef struct balloon_inflate_op {
+    unsigned long   size;
+    unsigned long   * pages;
+} balloon_inf_op_t;
+
+typedef struct dom_mem_ops
+{
+    unsigned int op;
+    union
+    {
+        balloon_def_op_t balloon_deflate;
+        balloon_inf_op_t balloon_inflate;
+    }u;
+} dom_mem_op_t;
diff --git a/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/dom0/dom0_core.c b/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/dom0/dom0_core.c
index f8af85358b..c36ab02e96 100644
--- a/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/dom0/dom0_core.c
+++ b/xenolinux-2.4.21-pre4-sparse/arch/xeno/drivers/dom0/dom0_core.c
@@ -53,7 +53,7 @@ typedef struct proc_mem_data {
 
 #define MAP_DISCONT     1
 
-static struct proc_dir_entry *xeno_base;
+struct proc_dir_entry *xeno_base;
 static struct proc_dir_entry *dom0_cmd_intf;
 static struct proc_dir_entry *proc_ft;
 
diff --git a/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/hypervisor.h b/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/hypervisor.h
index df25598730..16f37cfe65 100644
--- a/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/hypervisor.h
+++ b/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/hypervisor.h
@@ -313,4 +313,15 @@ static inline int HYPERVISOR_set_fast_trap(int idx)
     return ret;
 }
 
+static inline int HYPERVISOR_dom_mem_op(void *dom_mem_op)
+{
+    int ret;
+    __asm__ __volatile__ (
+        TRAP_INSTR
+        : "=a" (ret) : "0" (__HYPERVISOR_dom_mem_op),
+        "b" (dom_mem_op) : "memory" );
+
+    return ret;
+}
+
 #endif /* __HYPERVISOR_H__ */
diff --git a/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/page.h b/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/page.h
index e157a31a36..aad36820b7 100644
--- a/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/page.h
+++ b/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/page.h
@@ -173,6 +173,10 @@ static __inline__ int get_order(unsigned long size)
 #define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
 				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 
+/* VIRT <-> MACHINE conversion */
+#define virt_to_machine(_a) (phys_to_machine(__pa(_a)))
+#define machine_to_virt(_m) (__va(machine_to_phys(_m)))
+
 #endif /* __KERNEL__ */
 
 #endif /* _I386_PAGE_H */