Commit a929bee0e652 ("x86/vmx: Fix injection of #DB traps following
XSA-156") prevents an infinite loop in certain #DB traps. However, it
changed the behavior to not call hvm_hw_inject_trap() for #DB and #AC
traps which which means that the debug registers are not restored
correctly and nullified commit b56ae5b48c38 ("VMX: fix/adjust trap
injection").
To fix this, restore the original code path through hvm_inject_trap(),
but ensure that the struct hvm_trap is populated with all the required
data.
Signed-off-by: Ross Lagerwall
---
Changed in v2:
Use MASK_EXTR.
Only set instruction length for certain event types.
xen/arch/x86/hvm/vmx/vmx.c | 33 -
1 file changed, 20 insertions(+), 13 deletions(-)
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 9c5a388..bc4410f 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -3091,24 +3091,31 @@ static int vmx_handle_eoi_write(void)
* It is the callers responsibility to ensure that this function is only used
* in the context of an appropriate vmexit.
*/
-static void vmx_propagate_intr(void)
+static void vmx_propagate_intr(unsigned long intr)
{
-unsigned long intr, tmp;
-
-__vmread(VM_EXIT_INTR_INFO, &intr);
-
-ASSERT(intr & INTR_INFO_VALID_MASK);
-
-__vmwrite(VM_ENTRY_INTR_INFO, intr);
+struct hvm_trap trap = {
+.vector = MASK_EXTR(intr, INTR_INFO_VECTOR_MASK),
+.type = MASK_EXTR(intr, INTR_INFO_INTR_TYPE_MASK),
+};
+unsigned long tmp;
if ( intr & INTR_INFO_DELIVER_CODE_MASK )
{
__vmread(VM_EXIT_INTR_ERROR_CODE, &tmp);
-__vmwrite(VM_ENTRY_EXCEPTION_ERROR_CODE, tmp);
+trap.error_code = tmp;
}
+else
+trap.error_code = HVM_DELIVER_NO_ERROR_CODE;
+
+if ( trap.type >= X86_EVENTTYPE_SW_INTERRUPT )
+{
+__vmread(VM_EXIT_INSTRUCTION_LEN, &tmp);
+trap.insn_len = tmp;
+}
+else
+trap.insn_len = 0;
-__vmread(VM_EXIT_INSTRUCTION_LEN, &tmp);
-__vmwrite(VM_ENTRY_INSTRUCTION_LEN, tmp);
+hvm_inject_trap(&trap);
}
static void vmx_idtv_reinject(unsigned long idtv_info)
@@ -3366,7 +3373,7 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
HVMTRACE_1D(TRAP_DEBUG, exit_qualification);
write_debugreg(6, exit_qualification | DR_STATUS_RESERVED_ONE);
if ( !v->domain->debugger_attached )
-vmx_propagate_intr();
+vmx_propagate_intr(intr_info);
else
domain_pause_for_debugger();
break;
@@ -3437,7 +3444,7 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
break;
case TRAP_alignment_check:
HVMTRACE_1D(TRAP, vector);
-vmx_propagate_intr();
+vmx_propagate_intr(intr_info);
break;
case TRAP_nmi:
if ( MASK_EXTR(intr_info, INTR_INFO_INTR_TYPE_MASK) !=
--
2.4.3
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