KVM: x86 emulator: Add check_perm callback

This patch adds a check_perm callback for each opcode into
the instruction emulator. This will be used to do all
necessary permission checks on instructions before checking
whether they are intercepted or not.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Joerg Roedel 2011-04-04 12:39:25 +02:00 committed by Avi Kivity
parent 775fde8648
commit d09beabd7c
2 changed files with 15 additions and 0 deletions

View File

@ -222,6 +222,7 @@ struct decode_cache {
u8 seg_override;
unsigned int d;
int (*execute)(struct x86_emulate_ctxt *ctxt);
int (*check_perm)(struct x86_emulate_ctxt *ctxt);
unsigned long regs[NR_VCPU_REGS];
unsigned long eip;
/* modrm */

View File

@ -111,6 +111,7 @@ struct opcode {
struct group_dual *gdual;
struct gprefix *gprefix;
} u;
int (*check_perm)(struct x86_emulate_ctxt *ctxt);
};
struct group_dual {
@ -2425,12 +2426,17 @@ static int em_movdqu(struct x86_emulate_ctxt *ctxt)
#define D(_y) { .flags = (_y) }
#define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i }
#define DIP(_y, _i, _p) { .flags = (_y), .intercept = x86_intercept_##_i, \
.check_perm = (_p) }
#define N D(0)
#define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) }
#define GD(_f, _g) { .flags = ((_f) | Group | GroupDual), .u.gdual = (_g) }
#define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
#define II(_f, _e, _i) \
{ .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i }
#define IIP(_f, _e, _i, _p) \
{ .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i, \
.check_perm = (_p) }
#define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) }
#define D2bv(_f) D((_f) | ByteOp), D(_f)
@ -2873,6 +2879,7 @@ done_prefixes:
}
c->execute = opcode.u.execute;
c->check_perm = opcode.check_perm;
c->intercept = opcode.intercept;
/* Unrecognised? */
@ -3136,6 +3143,13 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
goto done;
}
/* Do instruction specific permission checks */
if (c->check_perm) {
rc = c->check_perm(ctxt);
if (rc != X86EMUL_CONTINUE)
goto done;
}
if (unlikely(ctxt->guest_mode) && c->intercept) {
rc = ops->intercept(ctxt, c->intercept,
X86_ICPT_POST_EXCEPT);