Messages in this thread | | | Subject | Re: [RESEND PATCH 1/2] KVM: X86: Add support for the emulation of DR6_BUS_LOCK bit | From | Xiaoyao Li <> | Date | Wed, 27 Jan 2021 11:41:21 +0800 |
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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; >
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