KVM: x86 emulator: change address linearization to return an error code

Preparing to add segment checks.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 39 insertions, 8 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index c522b4e3dbb0..b46fa374d0f1 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -489,8 +489,9 @@ static unsigned seg_override(struct x86_emulate_ctxt *ctxt,
         return c->seg_override;
 }
 
-static ulong linear(struct x86_emulate_ctxt *ctxt,
-                    struct segmented_address addr)
+static int linearize(struct x86_emulate_ctxt *ctxt,
+                     struct segmented_address addr,
+                     ulong *linear)
 {
         struct decode_cache *c = &ctxt->decode;
         ulong la;
@@ -498,7 +499,8 @@ static ulong linear(struct x86_emulate_ctxt *ctxt,
         la = seg_base(ctxt, ctxt->ops, addr.seg) + addr.ea;
         if (c->ad_bytes != 8)
                 la &= (u32)-1;
-        return la;
+        *linear = la;
+        return X86EMUL_CONTINUE;
 }
 
 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,
@@ -545,7 +547,13 @@ static int segmented_read_std(struct x86_emulate_ctxt *ctxt,
                               void *data,
                               unsigned size)
 {
-        return ctxt->ops->read_std(linear(ctxt, addr), data, size, ctxt->vcpu,
+        int rc;
+        ulong linear;
+
+        rc = linearize(ctxt, addr, &linear);
+        if (rc != X86EMUL_CONTINUE)
+                return rc;
+        return ctxt->ops->read_std(linear, data, size, ctxt->vcpu,
                                    &ctxt->exception);
 }
 
@@ -962,7 +970,13 @@ static int segmented_read(struct x86_emulate_ctxt *ctxt,
                           void *data,
                           unsigned size)
 {
-        return read_emulated(ctxt, ctxt->ops, linear(ctxt, addr), data, size);
+        int rc;
+        ulong linear;
+
+        rc = linearize(ctxt, addr, &linear);
+        if (rc != X86EMUL_CONTINUE)
+                return rc;
+        return read_emulated(ctxt, ctxt->ops, linear, data, size);
 }
 
 static int segmented_write(struct x86_emulate_ctxt *ctxt,
@@ -970,7 +984,13 @@ static int segmented_write(struct x86_emulate_ctxt *ctxt,
                            const void *data,
                            unsigned size)
 {
-        return ctxt->ops->write_emulated(linear(ctxt, addr), data, size,
+        int rc;
+        ulong linear;
+
+        rc = linearize(ctxt, addr, &linear);
+        if (rc != X86EMUL_CONTINUE)
+                return rc;
+        return ctxt->ops->write_emulated(linear, data, size,
                                          &ctxt->exception, ctxt->vcpu);
 }
 
@@ -979,7 +999,13 @@ static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt,
                              const void *orig_data, const void *data,
                              unsigned size)
 {
-        return ctxt->ops->cmpxchg_emulated(linear(ctxt, addr), orig_data, data,
+        int rc;
+        ulong linear;
+
+        rc = linearize(ctxt, addr, &linear);
+        if (rc != X86EMUL_CONTINUE)
+                return rc;
+        return ctxt->ops->cmpxchg_emulated(linear, orig_data, data,
                                            size, &ctxt->exception, ctxt->vcpu);
 }
 
@@ -2480,7 +2506,12 @@ static int em_movdqu(struct x86_emulate_ctxt *ctxt)
 static int em_invlpg(struct x86_emulate_ctxt *ctxt)
 {
         struct decode_cache *c = &ctxt->decode;
-        emulate_invlpg(ctxt->vcpu, linear(ctxt, c->src.addr.mem));
+        int rc;
+        ulong linear;
+
+        rc = linearize(ctxt, c->src.addr.mem, &linear);
+        if (rc == X86EMUL_CONTINUE)
+                emulate_invlpg(ctxt->vcpu, linear);
         /* Disable writeback. */
         c->dst.type = OP_NONE;
         return X86EMUL_CONTINUE;