linux/arch/x86/include/asm/lguest_hcall.h
Rusty Russell a489f0b555 lguest: fix guest crash on non-linear addresses in gdt pvops
Fixes guest crash 'lguest: bad read address 0x4800000 len 256'

The new per-cpu allocator ends up handing a non-linear address to
write_gdt_entry.  We do __pa() on it, and hand it to the host, which
kills us.

I've long wanted to make the hypercall "LOAD_GDT_ENTRY" to match the IDT
code, but had no pressing reason until now.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: lguest@ozlabs.org
2009-04-19 23:14:01 +09:30

56 lines
1.8 KiB
C

/* 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_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 LHCALL_LOAD_GDT_ENTRY 18
#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 <asm/hw_irq.h>
#include <asm/kvm_para.h>
/*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.
*
* We use the KVM hypercall mechanism. Eighteen hypercalls are
* available: the hypercall number is put in the %eax register, and the
* arguments (when required) are placed in %ebx, %ecx and %edx. 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". */
/*:*/
/* 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, arg1, arg2, arg3;
};
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_X86_LGUEST_HCALL_H */