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authorLinus Torvalds <torvalds@linux-foundation.org>2009-03-30 20:57:39 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-03-30 20:57:39 -0400
commitdb6f204019380c788f1de06ee937bdbccd60e5c0 (patch)
treef8ca32ab6932a21797dbc5aa77688ea017959da0 /arch/x86/include
parent3c6fae67d026d57f64eb3da9c0d0e76983e39ae3 (diff)
parentd1881d3192a3d3e8dc4f255b03187f4c36cb0617 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest-and-virtio
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest-and-virtio: lguest: barrier me harder lguest: use bool instead of int lguest: use KVM hypercalls lguest: wire up pte_update/pte_update_defer lguest: fix spurious BUG_ON() on invalid guest stack. virtio: more neatening of virtio_ring macros. virtio: fix BAD_RING, START_US and END_USE macros
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/lguest_hcall.h24
1 files changed, 4 insertions, 20 deletions
diff --git a/arch/x86/include/asm/lguest_hcall.h b/arch/x86/include/asm/lguest_hcall.h
index 43894428c3c2..0f4ee7148afe 100644
--- a/arch/x86/include/asm/lguest_hcall.h
+++ b/arch/x86/include/asm/lguest_hcall.h
@@ -26,36 +26,20 @@
26 26
27#ifndef __ASSEMBLY__ 27#ifndef __ASSEMBLY__
28#include <asm/hw_irq.h> 28#include <asm/hw_irq.h>
29#include <asm/kvm_para.h>
29 30
30/*G:031 But first, how does our Guest contact the Host to ask for privileged 31/*G:031 But first, how does our Guest contact the Host to ask for privileged
31 * operations? There are two ways: the direct way is to make a "hypercall", 32 * operations? There are two ways: the direct way is to make a "hypercall",
32 * to make requests of the Host Itself. 33 * to make requests of the Host Itself.
33 * 34 *
34 * Our hypercall mechanism uses the highest unused trap code (traps 32 and 35 * We use the KVM hypercall mechanism. Eighteen hypercalls are
35 * above are used by real hardware interrupts). Fifteen hypercalls are
36 * available: the hypercall number is put in the %eax register, and the 36 * available: the hypercall number is put in the %eax register, and the
37 * arguments (when required) are placed in %edx, %ebx and %ecx. If a return 37 * arguments (when required) are placed in %ebx, %ecx and %edx. If a return
38 * value makes sense, it's returned in %eax. 38 * value makes sense, it's returned in %eax.
39 * 39 *
40 * Grossly invalid calls result in Sudden Death at the hands of the vengeful 40 * Grossly invalid calls result in Sudden Death at the hands of the vengeful
41 * Host, rather than returning failure. This reflects Winston Churchill's 41 * Host, rather than returning failure. This reflects Winston Churchill's
42 * definition of a gentleman: "someone who is only rude intentionally". */ 42 * definition of a gentleman: "someone who is only rude intentionally". */
43static inline unsigned long
44hcall(unsigned long call,
45 unsigned long arg1, unsigned long arg2, unsigned long arg3)
46{
47 /* "int" is the Intel instruction to trigger a trap. */
48 asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
49 /* The call in %eax (aka "a") might be overwritten */
50 : "=a"(call)
51 /* The arguments are in %eax, %edx, %ebx & %ecx */
52 : "a"(call), "d"(arg1), "b"(arg2), "c"(arg3)
53 /* "memory" means this might write somewhere in memory.
54 * This isn't true for all calls, but it's safe to tell
55 * gcc that it might happen so it doesn't get clever. */
56 : "memory");
57 return call;
58}
59/*:*/ 43/*:*/
60 44
61/* Can't use our min() macro here: needs to be a constant */ 45/* Can't use our min() macro here: needs to be a constant */
@@ -64,7 +48,7 @@ hcall(unsigned long call,
64#define LHCALL_RING_SIZE 64 48#define LHCALL_RING_SIZE 64
65struct hcall_args { 49struct hcall_args {
66 /* These map directly onto eax, ebx, ecx, edx in struct lguest_regs */ 50 /* These map directly onto eax, ebx, ecx, edx in struct lguest_regs */
67 unsigned long arg0, arg2, arg3, arg1; 51 unsigned long arg0, arg1, arg2, arg3;
68}; 52};
69 53
70#endif /* !__ASSEMBLY__ */ 54#endif /* !__ASSEMBLY__ */