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Diffstat (limited to 'xen/include/public/xen.h')
| -rw-r--r-- | xen/include/public/xen.h | 425 |
1 files changed, 425 insertions, 0 deletions
diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h new file mode 100644 index 0000000000..f103509b04 --- /dev/null +++ b/xen/include/public/xen.h @@ -0,0 +1,425 @@ +/****************************************************************************** + * xen.h + * + * Guest OS interface to Xen. + * + * Copyright (c) 2004, K A Fraser + */ + +#ifndef __XEN_PUBLIC_XEN_H__ +#define __XEN_PUBLIC_XEN_H__ + +/* GCC-specific way to pack structure definitions (no implicit padding). */ +#define PACKED __attribute__ ((packed)) + +#if defined(__i386__) +#include "arch-x86_32.h" +#elif defined(__x86_64__) +#include "arch-x86_64.h" +#else +#error "Unsupported architecture" +#endif + +/* + * XEN "SYSTEM CALLS" (a.k.a. HYPERCALLS). + */ + +/* EAX = vector; EBX, ECX, EDX, ESI, EDI = args 1, 2, 3, 4, 5. */ +#define __HYPERVISOR_set_trap_table 0 +#define __HYPERVISOR_mmu_update 1 +#define __HYPERVISOR_set_gdt 2 +#define __HYPERVISOR_stack_switch 3 +#define __HYPERVISOR_set_callbacks 4 +#define __HYPERVISOR_fpu_taskswitch 5 +#define __HYPERVISOR_sched_op 6 +#define __HYPERVISOR_dom0_op 7 +#define __HYPERVISOR_set_debugreg 8 +#define __HYPERVISOR_get_debugreg 9 +#define __HYPERVISOR_update_descriptor 10 +#define __HYPERVISOR_set_fast_trap 11 +#define __HYPERVISOR_dom_mem_op 12 +#define __HYPERVISOR_multicall 13 +#define __HYPERVISOR_update_va_mapping 14 +#define __HYPERVISOR_set_timer_op 15 +#define __HYPERVISOR_event_channel_op 16 +#define __HYPERVISOR_xen_version 17 +#define __HYPERVISOR_console_io 18 +#define __HYPERVISOR_physdev_op 19 +#define __HYPERVISOR_grant_table_op 20 +#define __HYPERVISOR_vm_assist 21 +#define __HYPERVISOR_update_va_mapping_otherdomain 22 + +/* + * MULTICALLS + * + * Multicalls are listed in an array, with each element being a fixed size + * (BYTES_PER_MULTICALL_ENTRY). Each is of the form (op, arg1, ..., argN) + * where each element of the tuple is a machine word. + */ +#define ARGS_PER_MULTICALL_ENTRY 8 + + +/* + * VIRTUAL INTERRUPTS + * + * Virtual interrupts that a guest OS may receive from Xen. + */ +#define VIRQ_MISDIRECT 0 /* Catch-all interrupt for unbound VIRQs. */ +#define VIRQ_TIMER 1 /* Timebase update, and/or requested timeout. */ +#define VIRQ_DEBUG 2 /* Request guest to dump debug info. */ +#define VIRQ_CONSOLE 3 /* (DOM0) bytes received on emergency console. */ +#define VIRQ_DOM_EXC 4 /* (DOM0) Exceptional event for some domain. */ +#define VIRQ_PARITY_ERR 5 /* (DOM0) NMI parity error. */ +#define VIRQ_IO_ERR 6 /* (DOM0) NMI I/O error. */ +#define NR_VIRQS 7 + +/* + * MMU-UPDATE REQUESTS + * + * HYPERVISOR_mmu_update() accepts a list of (ptr, val) pairs. + * ptr[1:0] specifies the appropriate MMU_* command. + * + * FOREIGN DOMAIN (FD) + * ------------------- + * Some commands recognise an explicitly-declared foreign domain, + * in which case they will operate with respect to the foreigner rather than + * the calling domain. Where the FD has some effect, it is described below. + * + * ptr[1:0] == MMU_NORMAL_PT_UPDATE: + * Updates an entry in a page table. If updating an L1 table, and the new + * table entry is valid/present, the mapped frame must belong to the FD, if + * an FD has been specified. If attempting to map an I/O page then the + * caller assumes the privilege of the FD. + * FD == DOMID_IO: Permit /only/ I/O mappings, at the priv level of the caller. + * FD == DOMID_XEN: Map restricted areas of Xen's heap space. + * ptr[:2] -- Machine address of the page-table entry to modify. + * val -- Value to write. + * + * ptr[1:0] == MMU_MACHPHYS_UPDATE: + * Updates an entry in the machine->pseudo-physical mapping table. + * ptr[:2] -- Machine address within the frame whose mapping to modify. + * The frame must belong to the FD, if one is specified. + * val -- Value to write into the mapping entry. + * + * ptr[1:0] == MMU_EXTENDED_COMMAND: + * val[7:0] -- MMUEXT_* command. + * + * val[7:0] == MMUEXT_(UN)PIN_*_TABLE: + * ptr[:2] -- Machine address of frame to be (un)pinned as a p.t. page. + * The frame must belong to the FD, if one is specified. + * + * val[7:0] == MMUEXT_NEW_BASEPTR: + * ptr[:2] -- Machine address of new page-table base to install in MMU. + * + * val[7:0] == MMUEXT_TLB_FLUSH: + * No additional arguments. + * + * val[7:0] == MMUEXT_INVLPG: + * ptr[:2] -- Linear address to be flushed from the TLB. + * + * val[7:0] == MMUEXT_FLUSH_CACHE: + * No additional arguments. Writes back and flushes cache contents. + * + * val[7:0] == MMUEXT_SET_LDT: + * ptr[:2] -- Linear address of LDT base (NB. must be page-aligned). + * val[:8] -- Number of entries in LDT. + * + * val[7:0] == MMUEXT_TRANSFER_PAGE: + * val[31:16] -- Domain to whom page is to be transferred. + * (val[15:8],ptr[9:2]) -- 16-bit reference into transferee's grant table. + * ptr[:12] -- Page frame to be reassigned to the FD. + * (NB. The frame must currently belong to the calling domain). + * + * val[7:0] == MMUEXT_SET_FOREIGNDOM: + * val[31:16] -- Domain to set as the Foreign Domain (FD). + * (NB. DOMID_SELF is not recognised) + * If FD != DOMID_IO then the caller must be privileged. + * + * val[7:0] == MMUEXT_CLEAR_FOREIGNDOM: + * Clears the FD. + * + * val[7:0] == MMUEXT_REASSIGN_PAGE: + * ptr[:2] -- A machine address within the page to be reassigned to the FD. + * (NB. page must currently belong to the calling domain). + */ +#define MMU_NORMAL_PT_UPDATE 0 /* checked '*ptr = val'. ptr is MA. */ +#define MMU_MACHPHYS_UPDATE 2 /* ptr = MA of frame to modify entry for */ +#define MMU_EXTENDED_COMMAND 3 /* least 8 bits of val demux further */ +#define MMUEXT_PIN_L1_TABLE 0 /* ptr = MA of frame to pin */ +#define MMUEXT_PIN_L2_TABLE 1 /* ptr = MA of frame to pin */ +#define MMUEXT_PIN_L3_TABLE 2 /* ptr = MA of frame to pin */ +#define MMUEXT_PIN_L4_TABLE 3 /* ptr = MA of frame to pin */ +#define MMUEXT_UNPIN_TABLE 4 /* ptr = MA of frame to unpin */ +#define MMUEXT_NEW_BASEPTR 5 /* ptr = MA of new pagetable base */ +#define MMUEXT_TLB_FLUSH 6 /* ptr = NULL */ +#define MMUEXT_INVLPG 7 /* ptr = VA to invalidate */ +#define MMUEXT_FLUSH_CACHE 8 +#define MMUEXT_SET_LDT 9 /* ptr = VA of table; val = # entries */ +#define MMUEXT_SET_FOREIGNDOM 10 /* val[31:16] = dom */ +#define MMUEXT_CLEAR_FOREIGNDOM 11 +#define MMUEXT_TRANSFER_PAGE 12 /* ptr = MA of frame; val[31:16] = dom */ +#define MMUEXT_REASSIGN_PAGE 13 +#define MMUEXT_CMD_MASK 255 +#define MMUEXT_CMD_SHIFT 8 + +/* These are passed as 'flags' to update_va_mapping. They can be ORed. */ +#define UVMF_FLUSH_TLB 1 /* Flush entire TLB. */ +#define UVMF_INVLPG 2 /* Flush the VA mapping being updated. */ + + +/* + * Commands to HYPERVISOR_sched_op(). + */ +#define SCHEDOP_yield 0 /* Give up the CPU voluntarily. */ +#define SCHEDOP_block 1 /* Block until an event is received. */ +#define SCHEDOP_shutdown 2 /* Stop executing this domain. */ +#define SCHEDOP_cmdmask 255 /* 8-bit command. */ +#define SCHEDOP_reasonshift 8 /* 8-bit reason code. (SCHEDOP_shutdown) */ + +/* + * Commands to HYPERVISOR_console_io(). + */ +#define CONSOLEIO_write 0 +#define CONSOLEIO_read 1 + +/* + * Commands to HYPERVISOR_dom_mem_op(). + */ +#define MEMOP_increase_reservation 0 +#define MEMOP_decrease_reservation 1 + +/* + * Commands to HYPERVISOR_vm_assist(). + */ +#define VMASST_CMD_enable 0 +#define VMASST_CMD_disable 1 +#define VMASST_TYPE_4gb_segments 0 +#define VMASST_TYPE_4gb_segments_notify 1 +#define VMASST_TYPE_writable_pagetables 2 +#define MAX_VMASST_TYPE 2 + +#ifndef __ASSEMBLY__ + +typedef u16 domid_t; + +/* Domain ids >= DOMID_FIRST_RESERVED cannot be used for ordinary domains. */ +#define DOMID_FIRST_RESERVED (0x7FF0U) + +/* DOMID_SELF is used in certain contexts to refer to oneself. */ +#define DOMID_SELF (0x7FF0U) + +/* + * DOMID_IO is used to restrict page-table updates to mapping I/O memory. + * Although no Foreign Domain need be specified to map I/O pages, DOMID_IO + * is useful to ensure that no mappings to the OS's own heap are accidentally + * installed. (e.g., in Linux this could cause havoc as reference counts + * aren't adjusted on the I/O-mapping code path). + * This only makes sense in MMUEXT_SET_FOREIGNDOM, but in that context can + * be specified by any calling domain. + */ +#define DOMID_IO (0x7FF1U) + +/* + * DOMID_XEN is used to allow privileged domains to map restricted parts of + * Xen's heap space (e.g., the machine_to_phys table). + * This only makes sense in MMUEXT_SET_FOREIGNDOM, and is only permitted if + * the caller is privileged. + */ +#define DOMID_XEN (0x7FF2U) + +/* + * Send an array of these to HYPERVISOR_mmu_update(). + * NB. The fields are natural pointer/address size for this architecture. + */ +typedef struct +{ + memory_t ptr; /* Machine address of PTE. */ + memory_t val; /* New contents of PTE. */ +} PACKED mmu_update_t; + +/* + * Send an array of these to HYPERVISOR_multicall(). + * NB. The fields are natural register size for this architecture. + */ +typedef struct +{ + cpureg_t op; + cpureg_t args[7]; +} PACKED multicall_entry_t; + +/* Event channel endpoints per domain. */ +#define NR_EVENT_CHANNELS 1024 + +/* No support for multi-processor guests. */ +#define MAX_VIRT_CPUS 1 + +/* + * Xen/guestos shared data -- pointer provided in start_info. + * NB. We expect that this struct is smaller than a page. + */ +typedef struct shared_info_st +{ + /* + * Per-VCPU information goes here. This will be cleaned up more when Xen + * actually supports multi-VCPU guests. + */ + struct { + /* + * '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. + */ + u8 evtchn_upcall_pending; + u8 evtchn_upcall_mask; + u8 pad0, pad1; + } PACKED vcpu_data[MAX_VIRT_CPUS]; /* 0 */ + + /* + * A domain can have up to 1024 "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 the setup + * is initiated and organised by a privileged third party such as + * software running in domain 0). + * 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" between 0 and 1023. + * 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 + * 32-bit selector to be set. Each bit in the selector covers a 32-bit + * word in the PENDING bitfield array. + */ + u32 evtchn_pending[32]; /* 4 */ + u32 evtchn_pending_sel; /* 132 */ + u32 evtchn_mask[32]; /* 136 */ + + /* + * Time: The following abstractions are exposed: System Time, Clock Time, + * Domain Virtual Time. Domains can access Cycle counter time directly. + */ + u64 cpu_freq; /* 264: CPU frequency (Hz). */ + + /* + * The following values are updated periodically (and not necessarily + * atomically!). The guest OS detects this because 'time_version1' is + * incremented just before updating these values, and 'time_version2' is + * incremented immediately after. See the Xen-specific Linux code for an + * example of how to read these values safely (arch/xen/kernel/time.c). + */ + u32 time_version1; /* 272 */ + u32 time_version2; /* 276 */ + tsc_timestamp_t tsc_timestamp; /* TSC at last update of time vals. */ + u64 system_time; /* Time, in nanosecs, since boot. */ + u32 wc_sec; /* Secs 00:00:00 UTC, Jan 1, 1970. */ + u32 wc_usec; /* Usecs 00:00:00 UTC, Jan 1, 1970. */ + u64 domain_time; /* Domain virtual time, in nanosecs. */ + + /* + * Timeout values: + * Allow a domain to specify a timeout value in system time and + * domain virtual time. + */ + u64 wall_timeout; /* 312 */ + u64 domain_timeout; /* 320 */ + + arch_shared_info_t arch; + +} PACKED shared_info_t; + +/* + * Start-of-day memory layout for the initial domain (DOM0): + * 1. The domain is started within contiguous virtual-memory region. + * 2. The contiguous region begins and ends on an aligned 4MB boundary. + * 3. The region start corresponds to the load address of the OS image. + * If the load address is not 4MB aligned then the address is rounded down. + * 4. This the order of bootstrap elements in the initial virtual region: + * a. relocated kernel image + * b. initial ram disk [mod_start, mod_len] + * c. list of allocated page frames [mfn_list, nr_pages] + * d. bootstrap page tables [pt_base, CR3 (x86)] + * e. start_info_t structure [register ESI (x86)] + * f. bootstrap stack [register ESP (x86)] + * 5. Bootstrap elements are packed together, but each is 4kB-aligned. + * 6. The initial ram disk may be omitted. + * 7. The list of page frames forms a contiguous 'pseudo-physical' memory + * layout for the domain. In particular, the bootstrap virtual-memory + * region is a 1:1 mapping to the first section of the pseudo-physical map. + * 8. All bootstrap elements are mapped read-writable for the guest OS. The + * only exception is the bootstrap page table, which is mapped read-only. + * 9. There is guaranteed to be at least 512kB padding after the final + * bootstrap element. If necessary, the bootstrap virtual region is + * extended by an extra 4MB to ensure this. + */ + +#define MAX_CMDLINE 256 +typedef struct { + /* THE FOLLOWING ARE FILLED IN BOTH ON INITIAL BOOT AND ON RESUME. */ + memory_t nr_pages; /* 0: Total pages allocated to this domain. */ + _MEMORY_PADDING(A); + memory_t shared_info; /* 8: MACHINE address of shared info struct.*/ + _MEMORY_PADDING(B); + u32 flags; /* 16: SIF_xxx flags. */ + u16 domain_controller_evtchn; /* 20 */ + u16 __pad; + /* THE FOLLOWING ARE ONLY FILLED IN ON INITIAL BOOT (NOT RESUME). */ + memory_t pt_base; /* 24: VIRTUAL address of page directory. */ + _MEMORY_PADDING(C); + memory_t nr_pt_frames; /* 32: Number of bootstrap p.t. frames. */ + _MEMORY_PADDING(D); + memory_t mfn_list; /* 40: VIRTUAL address of page-frame list. */ + _MEMORY_PADDING(E); + memory_t mod_start; /* 48: VIRTUAL address of pre-loaded module. */ + _MEMORY_PADDING(F); + memory_t mod_len; /* 56: Size (bytes) of pre-loaded module. */ + _MEMORY_PADDING(G); + u8 cmd_line[MAX_CMDLINE]; /* 64 */ +} PACKED start_info_t; /* 320 bytes */ + +/* These flags are passed in the 'flags' field of start_info_t. */ +#define SIF_PRIVILEGED (1<<0) /* Is the domain privileged? */ +#define SIF_INITDOMAIN (1<<1) /* Is this the initial control domain? */ +#define SIF_BLK_BE_DOMAIN (1<<4) /* Is this a block backend domain? */ +#define SIF_NET_BE_DOMAIN (1<<5) /* Is this a net backend domain? */ + +/* For use in guest OSes. */ +extern shared_info_t *HYPERVISOR_shared_info; + +#endif /* !__ASSEMBLY__ */ + +#endif /* __XEN_PUBLIC_XEN_H__ */ |