[Patch v7 06/24] perf/x86: Use x86_perf_regs in the x86 nmi handler

[Dapeng Mi]

From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

More and more regs will be supported in the overflow, e.g., more vector
registers, SSP, etc. The generic pt_regs struct cannot store all of
them. Use a X86 specific x86_perf_regs instead.

The struct pt_regs *regs is still passed to x86_pmu_handle_irq(). There
is no functional change for the existing code.

AMD IBS's NMI handler doesn't utilize the static call
x86_pmu_handle_irq(). The x86_perf_regs struct doesn't apply to the AMD
IBS. It can be added separately later when AMD IBS supports more regs.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
---

V7: use per-cpu x86_intr_regs to replace temporary variable in v6.

 arch/x86/events/core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 67883cf1d675..ad6cbc19592d 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1782,9 +1782,11 @@ void perf_put_guest_lvtpc(void)
 EXPORT_SYMBOL_FOR_KVM(perf_put_guest_lvtpc);
 #endif /* CONFIG_PERF_GUEST_MEDIATED_PMU */
 
+static DEFINE_PER_CPU(struct x86_perf_regs, x86_intr_regs);
 static int
 perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
 {
+	struct x86_perf_regs *x86_regs = this_cpu_ptr(&x86_intr_regs);
 	u64 start_clock;
 	u64 finish_clock;
 	int ret;
@@ -1808,7 +1810,8 @@ perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
 		return NMI_DONE;
 
 	start_clock = sched_clock();
-	ret = static_call(x86_pmu_handle_irq)(regs);
+	x86_regs->regs = *regs;
+	ret = static_call(x86_pmu_handle_irq)(&x86_regs->regs);
 	finish_clock = sched_clock();
 
 	perf_sample_event_took(finish_clock - start_clock);
-- 
2.34.1