unsigned long address; /* code offset */
};
+struct arch_shared_info {
+ /*
+ * Number of valid entries in the p2m table(s) anchored at
+ * pfn_to_mfn_frame_list_list and/or p2m_vaddr.
+ */
+ unsigned long max_pfn;
+ /*
+ * Frame containing list of mfns containing list of mfns containing p2m.
+ * A value of 0 indicates it has not yet been set up, ~0 indicates it has
+ * been set to invalid e.g. due to the p2m being too large for the 3-level
+ * p2m tree. In this case the linear mapper p2m list anchored at p2m_vaddr
+ * is to be used.
+ */
+ xen_pfn_t pfn_to_mfn_frame_list_list;
+ unsigned long nmi_reason;
+ /*
+ * Following three fields are valid if p2m_cr3 contains a value different
+ * from 0.
+ * p2m_cr3 is the root of the address space where p2m_vaddr is valid.
+ * p2m_cr3 is in the same format as a cr3 value in the vcpu register state
+ * and holds the folded machine frame number (via xen_pfn_to_cr3) of a
+ * L3 or L4 page table.
+ * p2m_vaddr holds the virtual address of the linear p2m list. All entries
+ * in the range [0...max_pfn[ are accessible via this pointer.
+ * p2m_generation will be incremented by the guest before and after each
+ * change of the mappings of the p2m list. p2m_generation starts at 0 and
+ * a value with the least significant bit set indicates that a mapping
+ * update is in progress. This allows guest external software (e.g. in Dom0)
+ * to verify that read mappings are consistent and whether they have changed
+ * since the last check.
+ * Modifying a p2m element in the linear p2m list is allowed via an atomic
+ * write only.
+ */
+ unsigned long p2m_cr3; /* cr3 value of the p2m address space */
+ unsigned long p2m_vaddr; /* virtual address of the p2m list */
+ unsigned long p2m_generation; /* generation count of p2m mapping */
+#ifdef __i386__
+ /* There's no room for this field in the generic structure. */
+ uint32_t wc_sec_hi;
+#endif
+};
+
#endif
/**
#ifndef __ASSEMBLY__
+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.
+ */
+ uint32_t version;
+ uint32_t pad0;
+ uint64_t tsc_timestamp; /* TSC at last update of time vals. */
+ uint64_t 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
+ */
+ uint32_t tsc_to_system_mul;
+ int8_t tsc_shift;
+ uint8_t flags;
+ uint8_t pad1[2];
+}; /* 32 bytes */
+typedef struct vcpu_time_info vcpu_time_info_t;
+
+struct vcpu_info {
+ /*
+ * 'evtchn_upcall_pending' is written non-zero by Xen to indicate
+ * a pending notification for a particular VCPU. It is then cleared
+ * by the guest OS /before/ checking for pending work, thus avoiding
+ * a set-and-check race. Note that the mask is only accessed by Xen
+ * on the CPU that is currently hosting the VCPU. This means that the
+ * pending and mask flags can be updated by the guest without special
+ * synchronisation (i.e., no need for the x86 LOCK prefix).
+ * This may seem suboptimal because if the pending flag is set by
+ * a different CPU then an IPI may be scheduled even when the mask
+ * is set. However, note:
+ * 1. The task of 'interrupt holdoff' is covered by the per-event-
+ * channel mask bits. A 'noisy' event that is continually being
+ * triggered can be masked at source at this very precise
+ * granularity.
+ * 2. The main purpose of the per-VCPU mask is therefore to restrict
+ * reentrant execution: whether for concurrency control, or to
+ * prevent unbounded stack usage. Whatever the purpose, we expect
+ * that the mask will be asserted only for short periods at a time,
+ * and so the likelihood of a 'spurious' IPI is suitably small.
+ * The mask is read before making an event upcall to the guest: a
+ * non-zero mask therefore guarantees that the VCPU will not receive
+ * an upcall activation. The mask is cleared when the VCPU requests
+ * to block: this avoids wakeup-waiting races.
+ */
+ uint8_t evtchn_upcall_pending;
+ uint8_t evtchn_upcall_mask;
+ unsigned long evtchn_pending_sel;
+ struct arch_vcpu_info arch;
+ struct vcpu_time_info time;
+}; /* 64 bytes (x86) */
+
+struct shared_info {
+ struct vcpu_info vcpu_info[32];
+
+ /*
+ * A domain can create "event channels" on which it can send and receive
+ * asynchronous event notifications. There are three classes of event that
+ * are delivered by this mechanism:
+ * 1. Bi-directional inter- and intra-domain connections. Domains must
+ * arrange out-of-band to set up a connection (usually by allocating
+ * an unbound 'listener' port and avertising that via a storage service
+ * such as xenstore).
+ * 2. Physical interrupts. A domain with suitable hardware-access
+ * privileges can bind an event-channel port to a physical interrupt
+ * source.
+ * 3. Virtual interrupts ('events'). A domain can bind an event-channel
+ * port to a virtual interrupt source, such as the virtual-timer
+ * device or the emergency console.
+ *
+ * Event channels are addressed by a "port index". Each channel is
+ * associated with two bits of information:
+ * 1. PENDING -- notifies the domain that there is a pending notification
+ * to be processed. This bit is cleared by the guest.
+ * 2. MASK -- if this bit is clear then a 0->1 transition of PENDING
+ * will cause an asynchronous upcall to be scheduled. This bit is only
+ * updated by the guest. It is read-only within Xen. If a channel
+ * becomes pending while the channel is masked then the 'edge' is lost
+ * (i.e., when the channel is unmasked, the guest must manually handle
+ * pending notifications as no upcall will be scheduled by Xen).
+ *
+ * To expedite scanning of pending notifications, any 0->1 pending
+ * transition on an unmasked channel causes a corresponding bit in a
+ * per-vcpu selector word to be set. Each bit in the selector covers a
+ * 'C long' in the PENDING bitfield array.
+ */
+ unsigned long evtchn_pending[sizeof(unsigned long) * 8];
+ unsigned long evtchn_mask[sizeof(unsigned long) * 8];
+
+ /*
+ * Wallclock time: updated only by control software. Guests should base
+ * their gettimeofday() syscall on this wallclock-base value.
+ */
+ uint32_t wc_version; /* Version counter: see vcpu_time_info_t. */
+ uint32_t wc_sec; /* Secs 00:00:00 UTC, Jan 1, 1970. */
+ uint32_t wc_nsec; /* Nsecs 00:00:00 UTC, Jan 1, 1970. */
+#if !defined(__i386__)
+ uint32_t wc_sec_hi;
+#endif
+
+ struct arch_shared_info arch;
+};
+typedef struct shared_info shared_info_t;
+
struct start_info {
/* THE FOLLOWING ARE FILLED IN BOTH ON INITIAL BOOT AND ON RESUME. */
char magic[32]; /* "xen-<version>-<platform>". */