Messages in this thread | | | Date | Thu, 30 May 2019 11:46:02 -0700 | From | Sean Christopherson <> | Subject | Re: [PATCH] KVM: LAPIC: Do not mask the local interrupts when LAPIC is sw disabled |
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On Tue, May 21, 2019 at 06:44:15PM +0800, Luwei Kang wrote: > The current code will mask all the local interrupts in the local > vector table when the LAPIC is disabled by SVR (Spurious-Interrupt > Vector Register) "APIC Software Enable/Disable" flag (bit8). > This may block local interrupt be delivered to target vCPU > even if LAPIC is enabled by set SVR (bit8 == 1) after.
The current code aligns with the SDM, which states:
Local APIC State After It Has Been Software Disabled
When the APIC software enable/disable flag in the spurious interrupt vector register has been explicitly cleared (as opposed to being cleared during a power up or reset), the local APIC is temporarily disabled. The operation and response of a local APIC while in this software- disabled state is as follows:
- The mask bits for all the LVT entries are set. Attempts to reset these bits will be ignored.
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