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This commit is contained in:
Bernhard Stoeckner
2025-01-27 19:36:56 +01:00
parent 9d0b0414a5
commit 54d69484da
1166 changed files with 318863 additions and 182687 deletions
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59
kernel-open/nvidia-uvm/uvm_gpu_isr.c
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@@ -612,40 +612,35 @@ static void access_counters_isr_bottom_half_entry(void *args)
UVM_ENTRY_VOID(access_counters_isr_bottom_half(args));
}
// When Confidential Computing is enabled, UVM does not (indirectly) trigger
// the replayable fault interrupt by updating GET. This is because, in this
// configuration, GET is a dummy register used to inform GSP-RM (the owner
// of the HW replayable fault buffer) of the latest entry consumed by the
// UVM driver. The real GET register is owned by GSP-RM.
//
// The retriggering of a replayable faults bottom half happens then
// manually, by scheduling a bottom half for later if there is any pending
// work in the fault buffer accessible by UVM. The retriggering adddresses
// two problematic scenarios caused by GET updates not setting any
// interrupt:
//
// (1) UVM didn't process all the entries up to cached PUT
//
// (2) UVM did process all the entries up to cached PUT, but GSP-RM
// added new entries such that cached PUT is out-of-date
//
// In both cases, re-enablement of interrupts would have caused the
// replayable fault to be triggered in a non-CC setup, because the updated
// value of GET is different from PUT. But this not the case in Confidential
// Computing, so a bottom half needs to be manually scheduled in order to
// ensure that all faults are serviced.
//
// While in the typical case the retriggering happens within a replayable
// fault bottom half, it can also happen within a non-interrupt path such as
// uvm_gpu_fault_buffer_flush.
static void replayable_faults_retrigger_bottom_half(uvm_parent_gpu_t *parent_gpu)
{
bool retrigger = false;
// When Confidential Computing is enabled, UVM does not (indirectly) trigger
// the replayable fault interrupt by updating GET. This is because, in this
// configuration, GET is a dummy register used to inform GSP-RM (the owner
// of the HW replayable fault buffer) of the latest entry consumed by the
// UVM driver. The real GET register is owned by GSP-RM.
//
// The retriggering of a replayable faults bottom half happens then
// manually, by scheduling a bottom half for later if there is any pending
// work in the fault buffer accessible by UVM. The retriggering adddresses
// two problematic scenarios caused by GET updates not setting any
// interrupt:
//
// (1) UVM didn't process all the entries up to cached PUT
//
// (2) UVM did process all the entries up to cached PUT, but GSP-RM
// added new entries such that cached PUT is out-of-date
//
// In both cases, re-enablement of interrupts would have caused the
// replayable fault to be triggered in a non-CC setup, because the updated
// value of GET is different from PUT. But this not the case in Confidential
// Computing, so a bottom half needs to be manually scheduled in order to
// ensure that all faults are serviced.
//
// While in the typical case the retriggering happens within a replayable
// fault bottom half, it can also happen within a non-interrupt path such as
// uvm_gpu_fault_buffer_flush.
if (g_uvm_global.conf_computing_enabled)
retrigger = true;
if (!retrigger)
if (!g_uvm_global.conf_computing_enabled)
return;
uvm_spin_lock_irqsave(&parent_gpu->isr.interrupts_lock);