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Diffstat (limited to 'include/asm-x86/lguest_hcall.h')
-rw-r--r-- | include/asm-x86/lguest_hcall.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/include/asm-x86/lguest_hcall.h b/include/asm-x86/lguest_hcall.h new file mode 100644 index 000000000000..7859cfe0ebb2 --- /dev/null +++ b/include/asm-x86/lguest_hcall.h @@ -0,0 +1,67 @@ +/* Architecture specific portion of the lguest hypercalls */ +#ifndef _X86_LGUEST_HCALL_H +#define _X86_LGUEST_HCALL_H + +#define LHCALL_FLUSH_ASYNC 0 +#define LHCALL_LGUEST_INIT 1 +#define LHCALL_CRASH 2 +#define LHCALL_LOAD_GDT 3 +#define LHCALL_NEW_PGTABLE 4 +#define LHCALL_FLUSH_TLB 5 +#define LHCALL_LOAD_IDT_ENTRY 6 +#define LHCALL_SET_STACK 7 +#define LHCALL_TS 8 +#define LHCALL_SET_CLOCKEVENT 9 +#define LHCALL_HALT 10 +#define LHCALL_BIND_DMA 12 +#define LHCALL_SEND_DMA 13 +#define LHCALL_SET_PTE 14 +#define LHCALL_SET_PMD 15 +#define LHCALL_LOAD_TLS 16 + +/*G:031 First, how does our Guest contact the Host to ask for privileged + * operations? There are two ways: the direct way is to make a "hypercall", + * to make requests of the Host Itself. + * + * Our hypercall mechanism uses the highest unused trap code (traps 32 and + * above are used by real hardware interrupts). Seventeen hypercalls are + * available: the hypercall number is put in the %eax register, and the + * arguments (when required) are placed in %edx, %ebx and %ecx. If a return + * value makes sense, it's returned in %eax. + * + * Grossly invalid calls result in Sudden Death at the hands of the vengeful + * Host, rather than returning failure. This reflects Winston Churchill's + * definition of a gentleman: "someone who is only rude intentionally". */ +#define LGUEST_TRAP_ENTRY 0x1F + +static inline unsigned long +hcall(unsigned long call, + unsigned long arg1, unsigned long arg2, unsigned long arg3) +{ + /* "int" is the Intel instruction to trigger a trap. */ + asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY) + /* The call is in %eax (aka "a"), and can be replaced */ + : "=a"(call) + /* The other arguments are in %eax, %edx, %ebx & %ecx */ + : "a"(call), "d"(arg1), "b"(arg2), "c"(arg3) + /* "memory" means this might write somewhere in memory. + * This isn't true for all calls, but it's safe to tell + * gcc that it might happen so it doesn't get clever. */ + : "memory"); + return call; +} +/*:*/ + +void async_hcall(unsigned long call, + unsigned long arg1, unsigned long arg2, unsigned long arg3); + +/* Can't use our min() macro here: needs to be a constant */ +#define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32) + +#define LHCALL_RING_SIZE 64 +struct hcall_ring +{ + u32 eax, edx, ebx, ecx; +}; + +#endif /* _I386_LGUEST_HCALL_H */ |