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

Preparing to add segment checks.

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

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index c522b4e..b46fa37 100644 (file)
--- 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;