kernel: permit the use of IPIs prior to guest entry #628
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Until KVM supports separate interrupts per privilege context (VMPL, TDP L2, etc.), interrupt state must be exclusively associated with the guest OS, not with the SVSM. However, prior to the guest being started on any processor, there is no reason not to make use of interrupts in the SVSM because there is no ambiguity. This change permits the use of IPIs up to the point in time that all processors are ready to begin the request loop on all CPUs, at which point IPI usage is suppressed and interrupt state becomes exclusive to the guest OS. Signed-off-by: Jon Lange <jlange@microsoft.com>
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Until KVM supports separate interrupts per privilege context (VMPL, TDP L2, etc.), interrupt state must be exclusively associated with the guest OS, not with the SVSM. However, prior to the guest being started on any processor, there is no reason not to make use of interrupts in the SVSM because there is no ambiguity. This change permits the use of IPIs up to the point in time that all processors are ready to begin the request loop on all CPUs, at which point IPI usage is suppressed and interrupt state becomes exclusive to the guest OS.