[PATCH 2/4] target/i386: Added DR6 and DR7 consistency checks

[Lara Lazier]

DR6[63:32] and DR7[63:32] are reserved and need to be zero.
(AMD64 Architecture Programmer's Manual, V2, 15.5)

Signed-off-by: Lara Lazier <laramglazier@gmail.com>
---
 target/i386/svm.h                   | 2 ++
 target/i386/tcg/sysemu/svm_helper.c | 8 +++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/target/i386/svm.h b/target/i386/svm.h
index adc058dc76..e54670ef12 100644
--- a/target/i386/svm.h
+++ b/target/i386/svm.h
@@ -140,6 +140,8 @@
 #define SVM_MSRPM_SIZE         (1ULL << 13)
 #define SVM_IOPM_SIZE          ((1ULL << 13) + 1)
 
+#define SVM_DR_RESERVED_MASK 0xffffffff00000000U
+
 struct QEMU_PACKED vmcb_control_area {
        uint16_t intercept_cr_read;
        uint16_t intercept_cr_write;
diff --git a/target/i386/tcg/sysemu/svm_helper.c 
b/target/i386/tcg/sysemu/svm_helper.c
index fa701829e5..276c240f70 100644
--- a/target/i386/tcg/sysemu/svm_helper.c
+++ b/target/i386/tcg/sysemu/svm_helper.c
@@ -269,7 +269,13 @@ void helper_vmrun(CPUX86State *env, int aflag, int 
next_eip_addend)
     env->dr[6] = x86_ldq_phys(cs,
                           env->vm_vmcb + offsetof(struct vmcb, save.dr6));
 
-    /* FIXME: guest state consistency checks */
+    if (env->dr[6] & SVM_DR_RESERVED_MASK) {
+        cpu_vmexit(env, SVM_EXIT_ERR, 0, GETPC());
+    }
+
+    if (env->dr[7] & SVM_DR_RESERVED_MASK) {
+        cpu_vmexit(env, SVM_EXIT_ERR, 0, GETPC());
+    }
 
     switch (x86_ldub_phys(cs,
                       env->vm_vmcb + offsetof(struct vmcb, control.tlb_ctl))) {
-- 
2.25.1