[RFC PATCH 4/4] tmem: interface code for tmem on top of xen

Dan Magenheimer
2009-06-20T01:37:29Z

--- linux-2.6.30/arch/x86/include/asm/xen/hypercall.h 2009-06-09 21:05:27.000000000 -0600
+++ linux-2.6.30-tmem/arch/x86/include/asm/xen/hypercall.h 2009-06-19 13:49:04.000000000 -0600
@@ -45,6 +45,7 @@
#include <xen/interface/xen.h>
#include <xen/interface/sched.h>
#include <xen/interface/physdev.h>
+#include <xen/interface/tmem.h>

/*
* The hypercall asms have to meet several constraints:
@@ -417,6 +418,13 @@
return _hypercall2(int, nmi_op, op, arg);
}

+static inline int
+HYPERVISOR_tmem_op(
+ struct tmem_op *op)
+{
+ return _hypercall1(int, tmem_op, op);
+}
+
static inline void
MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
{
--- linux-2.6.30/drivers/xen/Makefile 2009-06-09 21:05:27.000000000 -0600
+++ linux-2.6.30-tmem/drivers/xen/Makefile 2009-06-19 09:33:59.000000000 -0600
@@ -3,5 +3,6 @@

obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o
obj-$(CONFIG_XEN_XENCOMM) += xencomm.o
+obj-$(CONFIG_TMEM) += tmem.o
obj-$(CONFIG_XEN_BALLOON) += balloon.o
obj-$(CONFIG_XENFS) += xenfs/
\ No newline at end of file
--- linux-2.6.30/include/xen/interface/tmem.h 1969-12-31 17:00:00.000000000 -0700
+++ linux-2.6.30-tmem/include/xen/interface/tmem.h 2009-06-19 11:21:24.000000000 -0600
@@ -0,0 +1,43 @@
+/*
+ * include/xen/interface/tmem.h
+ *
+ * Interface to Xen implementation of transcendent memory
+ *
+ * Copyright (C) 2009 Dan Magenheimer, Oracle Corp.
+ */
+
+#include <xen/interface/xen.h>
+
+#define TMEM_CONTROL 0
+#define TMEM_NEW_POOL 1
+#define TMEM_DESTROY_POOL 2
+#define TMEM_NEW_PAGE 3
+#define TMEM_PUT_PAGE 4
+#define TMEM_GET_PAGE 5
+#define TMEM_FLUSH_PAGE 6
+#define TMEM_FLUSH_OBJECT 7
+#define TMEM_READ 8
+#define TMEM_WRITE 9
+#define TMEM_XCHG 10
+
+/* Subops for HYPERVISOR_tmem_op(TMEM_CONTROL) */
+#define TMEMC_THAW 0
+#define TMEMC_FREEZE 1
+#define TMEMC_FLUSH 2
+#define TMEMC_DESTROY 3
+#define TMEMC_LIST 4
+#define TMEMC_SET_WEIGHT 5
+#define TMEMC_SET_CAP 6
+#define TMEMC_SET_COMPRESS 7
+
+/* Bits for HYPERVISOR_tmem_op(TMEM_NEW_POOL) */
+#define TMEM_POOL_PERSIST 1
+#define TMEM_POOL_SHARED 2
+#define TMEM_POOL_PAGESIZE_SHIFT 4
+#define TMEM_POOL_PAGESIZE_MASK 0xf
+#define TMEM_POOL_VERSION_SHIFT 24
+#define TMEM_POOL_VERSION_MASK 0xff
+
+/* Special errno values */
+#define EFROZEN 1000
+#define EEMPTY 1001
--- linux-2.6.30/include/xen/interface/xen.h 2009-06-09 21:05:27.000000000 -0600
+++ linux-2.6.30-tmem/include/xen/interface/xen.h 2009-06-19 14:39:15.000000000 -0600
@@ -58,6 +58,7 @@
#define __HYPERVISOR_event_channel_op 32
#define __HYPERVISOR_physdev_op 33
#define __HYPERVISOR_hvm_op 34
+#define __HYPERVISOR_tmem_op 38

/* Architecture-specific hypercall definitions. */
#define __HYPERVISOR_arch_0 48
@@ -461,6 +462,27 @@
#define __mk_unsigned_long(x) x ## UL
#define mk_unsigned_long(x) __mk_unsigned_long(x)

+struct tmem_op {
+ uint32_t cmd;
+ int32_t pool_id; /* private > 0; shared < 0; 0 is invalid */
+ union {
+ struct { /* for cmd == TMEM_NEW_POOL */
+ uint64_t uuid[2];
+ uint32_t flags;
+ } new;
+ struct {
+ uint64_t object;
+ uint32_t index;
+ uint32_t tmem_offset;
+ uint32_t pfn_offset;
+ uint32_t len;
+ GUEST_HANDLE(void) gmfn; /* guest machine page frame */
+ } gen;
+ } u;
+};
+typedef struct tmem_op tmem_op_t;
+DEFINE_GUEST_HANDLE_STRUCT(tmem_op_t);
+
#else /* __ASSEMBLY__ */

/* In assembly code we cannot use C numeric constant suffixes. */
--- linux-2.6.30/drivers/xen/tmem.c 1969-12-31 17:00:00.000000000 -0700
+++ linux-2.6.30-tmem/drivers/xen/tmem.c 2009-06-19 14:54:53.000000000 -0600
@@ -0,0 +1,106 @@
+/*
+ * Xen implementation for transcendent memory (tmem)
+ *
+ * Dan Magenheimer <dan.magenheimer@oracle.com> 2009
+ */
+
+#include <linux/types.h>
+#include <linux/tmem.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/tmem.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/page.h>
+
+struct tmem_ops *tmem_ops = NULL;
+
+static inline int xen_tmem_op(u32 tmem_cmd, u32 tmem_pool, u64 object,
+ u32 index, unsigned long gmfn, u32 tmem_offset, u32 pfn_offset, u32 len)
+{
+ struct tmem_op op;
+ int rc = 0;
+
+ op.cmd = tmem_cmd;
+ op.pool_id = tmem_pool;
+ op.u.gen.object = object;
+ op.u.gen.index = index;
+ op.u.gen.tmem_offset = tmem_offset;
+ op.u.gen.pfn_offset = pfn_offset;
+ op.u.gen.len = len;
+ set_xen_guest_handle(op.u.gen.gmfn, (void *)gmfn);
+ rc = HYPERVISOR_tmem_op(&op);
+ return rc;
+}
+
+static inline int xen_tmem_new_pool(uint32_t tmem_cmd, uint64_t uuid_lo,
+ uint64_t uuid_hi, uint32_t flags)
+{
+ struct tmem_op op;
+ int rc = 0;
+
+ op.cmd = tmem_cmd;
+ op.u.new.uuid[0] = uuid_lo;
+ op.u.new.uuid[1] = uuid_hi;
+ op.u.new.flags = flags;
+ rc = HYPERVISOR_tmem_op(&op);
+ return rc;
+}
+
+static int tmem_put_page(u32 pool_id, u64 object, u32 index,
+ unsigned long pfn)
+{
+ unsigned long gmfn = pfn_to_mfn(pfn);
+
+ return xen_tmem_op(TMEM_PUT_PAGE, pool_id, object, index,
+ gmfn, 0, 0, 0);
+}
+
+static int tmem_get_page(u32 pool_id, u64 object, u32 index,
+ unsigned long pfn)
+{
+ unsigned long gmfn = pfn_to_mfn(pfn);
+
+ return xen_tmem_op(TMEM_GET_PAGE, pool_id, object, index,
+ gmfn, 0, 0, 0);
+}
+
+static int tmem_flush_page(u32 pool_id, u64 object, u32 index)
+{
+ return xen_tmem_op(TMEM_FLUSH_PAGE, pool_id, object, index,
+ 0, 0, 0, 0);
+}
+
+static int tmem_flush_object(u32 pool_id, u64 object)
+{
+ return xen_tmem_op(TMEM_FLUSH_OBJECT, pool_id, object, 0, 0, 0, 0, 0);
+}
+
+static int tmem_new_pool(u64 uuid_lo, u64 uuid_hi, u32 flags)
+{
+ flags |= (PAGE_SHIFT - 12) << TMEM_POOL_PAGESIZE_SHIFT;
+ return xen_tmem_new_pool(TMEM_NEW_POOL, uuid_lo, uuid_hi, flags);
+}
+
+static int tmem_destroy_pool(u32 pool_id)
+{
+ return xen_tmem_op(TMEM_DESTROY_POOL, pool_id, 0, 0, 0, 0, 0, 0);
+}
+
+static int __init xen_tmem_init(void)
+{
+ if (tmem_ops != NULL)
+ printk(KERN_WARNING, "attempt to define multiple tmem_ops\n");
+ else
+ tmem_ops = kmalloc(sizeof(struct tmem_ops), GFP_KERNEL);
+
+ if (tmem_ops == NULL)
+ return -ENODEV;
+
+ tmem_ops->new_pool = tmem_new_pool;
+ tmem_ops->put_page = tmem_put_page;
+ tmem_ops->get_page = tmem_get_page;
+ tmem_ops->flush_page = tmem_flush_page;
+ tmem_ops->flush_object = tmem_flush_object;
+ tmem_ops->destroy_pool = tmem_destroy_pool;
+
+ return 0;
+}