[Xen-devel] [PATCH 08/10] Xen: Shared info for CPU yield support and xenbus protocol

[Daniel Castro <evil.dani@xxxxxxxxx>]

Shared info page added to complete the functionality to yield the
CPU while waiting for event arrival this is used in xenbus.

Xenbus protocol are the structs needed for a xenbus implementation,
they are defined in this patch but will be used later on.

Signed-off-by: Daniel Castro <evil.dani@xxxxxxxxx>
---
 src/bitops.h |   14 +++++
 src/xen.c    |   18 +++++++
 src/xen.h    |  156 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 188 insertions(+), 0 deletions(-)
 create mode 100644 src/bitops.h

diff --git a/src/bitops.h b/src/bitops.h
new file mode 100644
index 0000000..550edbb
--- /dev/null
+++ b/src/bitops.h
@@ -0,0 +1,14 @@
+#ifndef _BIT_OPS_H
+#define _BIT_OPS_H
+
+static inline int test_and_clear_bit(int nr, volatile void *addr)
+{
+    int oldbit;
+    asm volatile (
+        "lock ; btrl %2,%1 ; sbbl %0,%0"
+        : "=r" (oldbit), "=m" (*(volatile long *)addr)
+        : "Ir" (nr), "m" (*(volatile long *)addr) : "memory");
+    return oldbit;
+}
+
+#endif
diff --git a/src/xen.c b/src/xen.c
index 5e93a41..9e6c669 100644
--- a/src/xen.c
+++ b/src/xen.c
@@ -147,3 +147,21 @@ void xen_setup(void)
     RamSize = maxram;
     RamSizeOver4G = maxram_over4G;
 }
+
+struct shared_info *get_shared_info(void)
+{
+    static struct shared_info *shared_info = NULL;
+    struct xen_add_to_physmap xatp;
+
+    if (shared_info != NULL)
+        return shared_info;
+
+    xatp.domid = DOMID_SELF;
+    xatp.space = XENMAPSPACE_shared_info;
+    xatp.idx   = 0;
+    xatp.gpfn  = 0xfffffu;
+    shared_info = (struct shared_info *)(xatp.gpfn << PAGE_SHIFT);
+    if (hypercall_memory_op(XENMEM_add_to_physmap, &xatp) != 0)
+        panic("MAP info page fail");
+    return shared_info;
+}
diff --git a/src/xen.h b/src/xen.h
index b70593a..06c87b0 100644
--- a/src/xen.h
+++ b/src/xen.h
@@ -2,6 +2,7 @@
 #define __XEN_H
 
 #include "util.h"
+#include "config.h"
 
 extern u32 xen_cpuid_base;
 
@@ -146,6 +147,80 @@ typedef unsigned long xen_pfn_t;
 #define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = val; } while (0)
 #define set_xen_guest_handle(hnd, val) set_xen_guest_handle_raw(hnd, val)
 
+/****
+ * This is needed to get the shared info page
+ ****/
+
+
+struct arch_shared_info {
+       unsigned long max_pfn;                  /* max pfn that appears in 
table */
+       /* Frame containing list of mfns containing list of mfns containing 
p2m. */
+       xen_pfn_t     pfn_to_mfn_frame_list_list;
+       unsigned long nmi_reason;
+       u64 pad[32];
+};
+typedef struct arch_shared_info arch_shared_info_t;
+
+struct arch_vcpu_info {
+       unsigned long cr2;
+       unsigned long pad[5]; /* sizeof(vcpu_info_t) == 64 */
+};
+typedef struct arch_vcpu_info arch_vcpu_info_t;
+
+struct vcpu_time_info {
+       /*
+        * Updates to the following values are preceded and followed by an
+        * increment of 'version'. The guest can therefore detect updates by
+        * looking for changes to 'version'. If the least-significant bit of
+        * the version number is set then an update is in progress and the guest
+        * must wait to read a consistent set of values.
+        * The correct way to interact with the version number is similar to
+        * Linux's seqlock: see the implementations of 
read_seqbegin/read_seqretry.
+        */
+       u32 version;
+       u32 pad0;
+       u64 tsc_timestamp;   /* TSC at last update of time vals.  */
+       u64 system_time;     /* Time, in nanosecs, since boot.    */
+       /*
+        * Current system time:
+        *   system_time +
+        *   ((((tsc - tsc_timestamp) << tsc_shift) * tsc_to_system_mul) >> 32)
+        * CPU frequency (Hz):
+        *   ((10^9 << 32) / tsc_to_system_mul) >> tsc_shift
+        */
+       u32 tsc_to_system_mul;
+       u8   tsc_shift;
+       u8   pad1[3];
+}; /* 32 bytes */
+typedef struct vcpu_time_info vcpu_time_info_t;
+
+
+struct vcpu_info {
+       u8 evtchn_upcall_pending;
+       u8 evtchn_upcall_mask;
+       unsigned long evtchn_pending_sel;
+       struct arch_vcpu_info arch;
+       struct vcpu_time_info time;
+};  /*64 bytes (x86)*/
+
+#define XEN_LEGACY_MAX_VCPUS 32
+
+struct shared_info {
+       struct vcpu_info vcpu_info[XEN_LEGACY_MAX_VCPUS];
+       unsigned long evtchn_pending[sizeof(unsigned long) * 8];
+       unsigned long evtchn_mask[sizeof(unsigned long) * 8];
+       u32 wc_version;      /* Version counter: see vcpu_time_info_t. */
+       u32 wc_sec;          /* Secs  00:00:00 UTC, Jan 1, 1970.  */
+       u32 wc_nsec;         /* Nsecs 00:00:00 UTC, Jan 1, 1970.  */
+
+       struct arch_shared_info arch;
+
+};
+typedef struct shared_info shared_info_t;
+
+
+struct shared_info *get_shared_info(void);
+
 /******************************************************************************
  * version.h
  *
@@ -218,6 +293,7 @@ struct xen_hvm_param {
     u64 value;    //IN/OUT
 };
 
+
 /******************************************************************************
  * event_channel.h
  *
@@ -271,6 +347,86 @@ DEFINE_XEN_GUEST_HANDLE(sched_poll_t);
 #define        ENOSYS          38      /* Function not implemented */
 #define        EISCONN         106     /* Transport endpoint is already 
connected */
 
+/*
+ * xs_wire.h
+ * Details of the "wire" protocol between Xen Store Daemon and client
+ * library or guest kernel.
+ *
+ * Copyright (C) 2005 Rusty Russell IBM Corporation
+ */
+#define XENSTORE_PAYLOAD_MAX 4096
+
+enum xsd_sockmsg_type
+{
+    XS_DEBUG,
+    XS_DIRECTORY,
+    XS_READ,
+    XS_GET_PERMS,
+    XS_WATCH,
+    XS_UNWATCH,
+    XS_TRANSACTION_START,
+    XS_TRANSACTION_END,
+    XS_INTRODUCE,
+    XS_RELEASE,
+    XS_GET_DOMAIN_PATH,
+    XS_WRITE,
+    XS_MKDIR,
+    XS_RM,
+    XS_SET_PERMS,
+    XS_WATCH_EVENT,
+    XS_ERROR,
+    XS_IS_DOMAIN_INTRODUCED,
+    XS_RESUME,
+    XS_SET_TARGET,
+    XS_RESTRICT
+};
+
+#define XS_WRITE_NONE "NONE"
+#define XS_WRITE_CREATE "CREATE"
+#define XS_WRITE_CREATE_EXCL "CREATE|EXCL"
+
+/* We hand errors as strings, for portability. */
+struct xsd_errors
+{
+    int errnum;
+    const char *errstring;
+};
+
+struct xsd_sockmsg
+{
+    u32 type;  /* XS_??? */
+    u32 req_id;/* Request identifier, echoed in daemon's response.  */
+    u32 tx_id; /* Transaction id (0 if not related to a transaction). */
+    u32 len;   /* Length of data following this. */
+
+    /* Generally followed by nul-terminated string(s). */
+};
+
+enum xs_watch_type
+{
+    XS_WATCH_PATH = 0,
+    XS_WATCH_TOKEN
+};
+
+/* Inter-domain shared memory communications. */
+#define XENSTORE_RING_SIZE 1024
+typedef u32 XENSTORE_RING_IDX;
+#define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
+struct xenstore_domain_interface {
+    char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
+    char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
+    XENSTORE_RING_IDX req_cons, req_prod;
+    XENSTORE_RING_IDX rsp_cons, rsp_prod;
+};
+
+#define XSD_ERROR(x) { x, #x }
+static struct xsd_errors __attribute__ ((unused)) xsd_errors[]
+    = {
+    XSD_ERROR(EINVAL),
+    XSD_ERROR(EACCES),
+    XSD_ERROR(EIO),
+    XSD_ERROR(EISCONN)
+};
 
 /******************************************************************************
  * memory.h
-- 
1.7.4.1


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