Re: VMI Interface Proposal Documentation for I386, Part 5

On Mon, 13 Mar 2006, Zachary Amsden wrote:

PROCESSOR STATE CALLS

This set of calls controls the online status of the processor. It
include interrupt control, reboot, halt, and shutdown functionality.
Future expansions may include deep sleep and hotplug CPU capabilities.

VMI_DisableInterrupts

VMICALL void VMI_DisableInterrupts(void);

Disable maskable interrupts on the processor.

Inputs: None
Outputs: None
Clobbers: Flags only
Segments: As this is both performance critical and likely to
be called from low level interrupt code, this call does not
require flat DS/ES segments, but uses the stack segment for
data access. Therefore only CS/SS must be well defined.

VMI_EnableInterrupts

VMICALL void VMI_EnableInterrupts(void);

Enable maskable interrupts on the processor. Note that the
current implementation always will deliver any pending interrupts
on a call which enables interrupts, for compatibility with kernel
code which expects this behavior. Whether this should be required
is open for debate.

Mind if i push this debate slightly forward? If we were to move the
dispatch of pending interrupts elsewhere, where would that be? In
particular, for a device which won't issue any more interrupts until it's
previous interrupt is serviced. Perhaps injection at arbitrary points
during runtime when interrupts are enabled?

Zwane

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