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87693645ae
When a guest PEBS counter is cross-mapped by a host counter, software
will remove the corresponding bit in the arr[global_ctrl].guest and
expect hardware to perform a change of state "from enable to disable"
via the msr_slot[] switch during the vmx transaction.
The real world is that if user adjust the counter overflow value small
enough, it still opens a tiny race window for the previously PEBS-enabled
counter to write cross-mapped PEBS records into the guest's PEBS buffer,
when arr[global_ctrl].guest has been prioritised (switch_msr_special stuff)
to switch into the enabled state, while the arr[pebs_enable].guest has not.
Close this window by clearing invalid bits in the arr[global_ctrl].guest.
Cc: linux-perf-users@vger.kernel.org
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <seanjc@google.com>
Fixes:
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| .. | ||
| alpha | ||
| arc | ||
| arm | ||
| arm64 | ||
| csky | ||
| hexagon | ||
| ia64 | ||
| loongarch | ||
| m68k | ||
| microblaze | ||
| mips | ||
| nios2 | ||
| openrisc | ||
| parisc | ||
| powerpc | ||
| riscv | ||
| s390 | ||
| sh | ||
| sparc | ||
| um | ||
| x86 | ||
| xtensa | ||
| .gitignore | ||
| Kconfig | ||