[RFC PATCH 01/12] perf/x86: Use x86_perf_regs in the x86 nmi handler

[kan . liang]

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 the X86 specific x86_perf_regs instead. The x86_perf_regs is
already used in PEBS to store the XMM registers.

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>
---
 arch/x86/events/core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 7610f26dfbd9..64a7a8aa2e38 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1752,6 +1752,7 @@ void perf_events_lapic_init(void)
 static int
 perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
 {
+	struct x86_perf_regs x86_regs;
 	u64 start_clock;
 	u64 finish_clock;
 	int ret;
@@ -1764,7 +1765,8 @@ 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);
-- 
2.38.1