From bb8985586b7a906e116db835c64773b7a7d51663 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 17 Aug 2008 21:05:42 -0400 Subject: x86, um: ... and asm-x86 move Signed-off-by: Al Viro Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/lguest_hcall.h | 71 +++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 arch/x86/include/asm/lguest_hcall.h (limited to 'arch/x86/include/asm/lguest_hcall.h') diff --git a/arch/x86/include/asm/lguest_hcall.h b/arch/x86/include/asm/lguest_hcall.h new file mode 100644 index 0000000..8f034ba --- /dev/null +++ b/arch/x86/include/asm/lguest_hcall.h @@ -0,0 +1,71 @@ +/* Architecture specific portion of the lguest hypercalls */ +#ifndef ASM_X86__LGUEST_HCALL_H +#define ASM_X86__LGUEST_HCALL_H + +#define LHCALL_FLUSH_ASYNC 0 +#define LHCALL_LGUEST_INIT 1 +#define LHCALL_SHUTDOWN 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_SET_PTE 14 +#define LHCALL_SET_PMD 15 +#define LHCALL_LOAD_TLS 16 +#define LHCALL_NOTIFY 17 + +#define LGUEST_TRAP_ENTRY 0x1F + +/* Argument number 3 to LHCALL_LGUEST_SHUTDOWN */ +#define LGUEST_SHUTDOWN_POWEROFF 1 +#define LGUEST_SHUTDOWN_RESTART 2 + +#ifndef __ASSEMBLY__ +#include + +/*G:031 But 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). Fifteen 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". */ +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 in %eax (aka "a") might be overwritten */ + : "=a"(call) + /* The 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; +} +/*:*/ + +/* 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_args { + /* These map directly onto eax, ebx, ecx, edx in struct lguest_regs */ + unsigned long arg0, arg2, arg3, arg1; +}; + +#endif /* !__ASSEMBLY__ */ +#endif /* ASM_X86__LGUEST_HCALL_H */ -- cgit v1.1