On 05/07/21 10:18, Lara Lazier wrote:
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 <laramglaz...@gmail.com>

The checks need to be disabled on 32-bit builds where env->dr[6] and env->dr[7] is a 32-bit value (compilers or static analyzers would complain about always-zero conditions) but otherwise the patch is fine. When you fetch from the QEMU repository and rebase, you will be able to use my changes just with "git rebase --skip".

Queued, thanks.

Paolo

---
  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))) 
{



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