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>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index a2c31e5..4822824 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -111,6 +111,7 @@
struct group_dual *gdual;
struct gprefix *gprefix;
} u;
+ int (*check_perm)(struct x86_emulate_ctxt *ctxt);
};
struct group_dual {
@@ -2425,12 +2426,17 @@
#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 @@
}
c->execute = opcode.u.execute;
+ c->check_perm = opcode.check_perm;
c->intercept = opcode.intercept;
/* Unrecognised? */
@@ -3136,6 +3143,13 @@
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);