The high halves of all GPRs are undefined in 32-bit and compat modes,
and the dependency is being obfuscated by our structure field names not
matching architectural register names (it was actually while putting
together a patch to correct this when I noticed the issue here).
For consistency also use the architecturally correct names on the
output side.
Signed-off-by: Jan Beulich
--- a/xen/arch/x86/hvm/viridian.c
+++ b/xen/arch/x86/hvm/viridian.c
@@ -667,9 +667,9 @@ int viridian_hypercall(struct cpu_user_r
output_params_gpa = regs->r8;
break;
case 4:
-input.raw = ((uint64_t)regs->edx << 32) | regs->eax;
-input_params_gpa = ((uint64_t)regs->ebx << 32) | regs->ecx;
-output_params_gpa = ((uint64_t)regs->edi << 32) | regs->esi;
+input.raw = (regs->rdx << 32) | regs->_eax;
+input_params_gpa = (regs->rbx << 32) | regs->_ecx;
+output_params_gpa = (regs->rdi << 32) | regs->_esi;
break;
default:
goto out;
@@ -770,8 +770,8 @@ out:
regs->rax = output.raw;
break;
default:
-regs->edx = output.raw >> 32;
-regs->eax = output.raw;
+regs->rdx = output.raw >> 32;
+regs->rax = (uint32_t)output.raw;
break;
}
x86/Viridian: don't depend on undefined register state
The high halves of all GPRs are undefined in 32-bit and compat modes,
and the dependency is being obfuscated by our structure field names not
matching architectural register names (it was actually while putting
together a patch to correct this when I noticed the issue here).
For consistency also use the architecturally correct names on the
output side.
Signed-off-by: Jan Beulich
--- a/xen/arch/x86/hvm/viridian.c
+++ b/xen/arch/x86/hvm/viridian.c
@@ -667,9 +667,9 @@ int viridian_hypercall(struct cpu_user_r
output_params_gpa = regs->r8;
break;
case 4:
-input.raw = ((uint64_t)regs->edx << 32) | regs->eax;
-input_params_gpa = ((uint64_t)regs->ebx << 32) | regs->ecx;
-output_params_gpa = ((uint64_t)regs->edi << 32) | regs->esi;
+input.raw = (regs->rdx << 32) | regs->_eax;
+input_params_gpa = (regs->rbx << 32) | regs->_ecx;
+output_params_gpa = (regs->rdi << 32) | regs->_esi;
break;
default:
goto out;
@@ -770,8 +770,8 @@ out:
regs->rax = output.raw;
break;
default:
-regs->edx = output.raw >> 32;
-regs->eax = output.raw;
+regs->rdx = output.raw >> 32;
+regs->rax = (uint32_t)output.raw;
break;
}
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