On 1/27/2021 12:31 AM, Paolo Bonzini wrote:
On 08/01/21 07:49, Chenyi Qiang wrote:
To avoid breaking the CPUs without bus lock detection, activate the
DR6_BUS_LOCK bit (bit 11) conditionally in DR6_FIXED_1 bits.
The set/clear of DR6_BUS_LOCK is similar to the DR6_RTM in DR6
register. The processor clears DR6_BUS_LOCK when bus lock debug
exception is generated. (For all other #DB the processor sets this bit
to 1.) Software #DB handler should set this bit before returning to the
interrupted task.
For VM exit caused by debug exception, bit 11 of the exit qualification
is set to indicate that a bus lock debug exception condition was
detected. The VMM should emulate the exception by clearing bit 11 of the
guest DR6.
Please rename DR6_INIT to DR6_ACTIVE_LOW, and then a lot of changes
become simpler:
Paolo,
What do you want to convey with the new name DR6_ACTIVE_LOW? To be
honest, the new name is confusing to me.
- dr6 |= DR6_BD | DR6_RTM;
+ dr6 |= DR6_BD | DR6_RTM | DR6_BUS_LOCK;
dr6 |= DR6_BD | DR6_ACTIVE_LOW;
