AMD Phenom 8450 Triple-Core HD8450WCGHBOX User Manual
Product codes
HD8450WCGHBOX
Product Errata
23
Revision Guide for AMD Family 10h Processors
41322
Rev. 3.16
February 2008
246 Breakpoint Due to An Instruction That Has an Interrupt Shadow
May Be Delivered to the Hypervisor
Description
A #DB exception occurring in guest mode may be delivered in the host context under the following
conditions:
conditions:
•
A trap-type #DB exception is generated in guest mode during execution of an instruction with an
interrupt shadow, and
interrupt shadow, and
•
The instruction that generated the exception is immediately followed by an instruction resulting in
#VMEXIT.
#VMEXIT.
Potential Effect on System
Unpredictable results due to an unexpected #DB exception.
Suggested Workaround
The hypervisor should have a valid interrupt gate in the IDT of the #DB handler entry and the handler
must be able to determine that this event has occurred. If the event is detected, the handler should
execute an IRET back to the hypervisor; one method that could be used to evaluate for this condition
is to compare the RIP pushed on the stack to the RIP of the instruction following VMRUN, if they are
equivalent then this event has occurred.
must be able to determine that this event has occurred. If the event is detected, the handler should
execute an IRET back to the hypervisor; one method that could be used to evaluate for this condition
is to compare the RIP pushed on the stack to the RIP of the instruction following VMRUN, if they are
equivalent then this event has occurred.
Fix Planned
Yes