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linux/arch/powerpc/include/asm/lppaca.h
Gautam Menghani e1f288d2f9 KVM: PPC: Book3S HV nestedv2: Add support for reading VPA counters for pseries guests
PAPR hypervisor has introduced three new counters in the VPA area of
LPAR CPUs for KVM L2 guest (see [1] for terminology) observability - two
for context switches from host to guest and vice versa, and one counter
for getting the total time spent inside the KVM guest. Add a tracepoint
that enables reading the counters for use by ftrace/perf. Note that this
tracepoint is only available for nestedv2 API (i.e, KVM on PowerVM).

[1] Terminology:
a. L1 refers to the VM (LPAR) booted on top of PAPR hypervisor
b. L2 refers to the KVM guest booted on top of L1.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240520175742.196329-1-gautam@linux.ibm.com
2024-06-03 22:06:28 +10:00

149 lines
4.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* lppaca.h
* Copyright (C) 2001 Mike Corrigan IBM Corporation
*/
#ifndef _ASM_POWERPC_LPPACA_H
#define _ASM_POWERPC_LPPACA_H
#ifdef __KERNEL__
/*
* These definitions relate to hypervisors that only exist when using
* a server type processor
*/
#ifdef CONFIG_PPC_BOOK3S
/*
* This control block contains the data that is shared between the
* hypervisor and the OS.
*/
#include <linux/cache.h>
#include <linux/threads.h>
#include <asm/types.h>
#include <asm/mmu.h>
#include <asm/firmware.h>
#include <asm/paca.h>
/*
* The lppaca is the "virtual processor area" registered with the hypervisor,
* H_REGISTER_VPA etc.
*
* According to PAPR, the structure is 640 bytes long, must be L1 cache line
* aligned, and must not cross a 4kB boundary. Its size field must be at
* least 640 bytes (but may be more).
*
* Pre-v4.14 KVM hypervisors reject the VPA if its size field is smaller than
* 1kB, so we dynamically allocate 1kB and advertise size as 1kB, but keep
* this structure as the canonical 640 byte size.
*/
struct lppaca {
/* cacheline 1 contains read-only data */
__be32 desc; /* Eye catcher 0xD397D781 */
__be16 size; /* Size of this struct */
u8 reserved1[3];
u8 __old_status; /* Old status, including shared proc */
u8 reserved3[14];
volatile __be32 dyn_hw_node_id; /* Dynamic hardware node id */
volatile __be32 dyn_hw_proc_id; /* Dynamic hardware proc id */
u8 reserved4[56];
volatile u8 vphn_assoc_counts[8]; /* Virtual processor home node */
/* associativity change counters */
u8 reserved5[32];
/* cacheline 2 contains local read-write data */
u8 reserved6[48];
u8 cede_latency_hint;
u8 ebb_regs_in_use;
u8 reserved7[6];
u8 dtl_enable_mask; /* Dispatch Trace Log mask */
u8 donate_dedicated_cpu; /* Donate dedicated CPU cycles */
u8 fpregs_in_use;
u8 pmcregs_in_use;
u8 l2_counters_enable; /* Enable usage of counters for KVM guest */
u8 reserved8[27];
__be64 wait_state_cycles; /* Wait cycles for this proc */
u8 reserved9[28];
__be16 slb_count; /* # of SLBs to maintain */
u8 idle; /* Indicate OS is idle */
u8 vmxregs_in_use;
/* cacheline 3 is shared with other processors */
/*
* This is the yield_count. An "odd" value (low bit on) means that
* the processor is yielded (either because of an OS yield or a
* hypervisor preempt). An even value implies that the processor is
* currently executing.
* NOTE: Even dedicated processor partitions can yield so this
* field cannot be used to determine if we are shared or dedicated.
*/
volatile __be32 yield_count;
volatile __be32 dispersion_count; /* dispatch changed physical cpu */
volatile __be64 cmo_faults; /* CMO page fault count */
volatile __be64 cmo_fault_time; /* CMO page fault time */
u8 reserved10[64]; /* [S]PURR expropriated/donated */
volatile __be64 enqueue_dispatch_tb; /* Total TB enqueue->dispatch */
volatile __be64 ready_enqueue_tb; /* Total TB ready->enqueue */
volatile __be64 wait_ready_tb; /* Total TB wait->ready */
u8 reserved11[16];
/* cacheline 4-5 */
__be32 page_ins; /* CMO Hint - # page ins by OS */
u8 reserved12[28];
volatile __be64 l1_to_l2_cs_tb;
volatile __be64 l2_to_l1_cs_tb;
volatile __be64 l2_runtime_tb;
u8 reserved13[96];
volatile __be64 dtl_idx; /* Dispatch Trace Log head index */
u8 reserved14[96];
} ____cacheline_aligned;
#define lppaca_of(cpu) (*paca_ptrs[cpu]->lppaca_ptr)
/*
* We are using a non architected field to determine if a partition is
* shared or dedicated. This currently works on both KVM and PHYP, but
* we will have to transition to something better.
*/
#define LPPACA_OLD_SHARED_PROC 2
#ifdef CONFIG_PPC_PSERIES
/*
* All CPUs should have the same shared proc value, so directly access the PACA
* to avoid false positives from DEBUG_PREEMPT.
*/
static inline bool lppaca_shared_proc(void)
{
struct lppaca *l = local_paca->lppaca_ptr;
if (!firmware_has_feature(FW_FEATURE_SPLPAR))
return false;
return !!(l->__old_status & LPPACA_OLD_SHARED_PROC);
}
#define get_lppaca() (get_paca()->lppaca_ptr)
#endif
/*
* SLB shadow buffer structure as defined in the PAPR. The save_area
* contains adjacent ESID and VSID pairs for each shadowed SLB. The
* ESID is stored in the lower 64bits, then the VSID.
*/
struct slb_shadow {
__be32 persistent; /* Number of persistent SLBs */
__be32 buffer_length; /* Total shadow buffer length */
__be64 reserved;
struct {
__be64 esid;
__be64 vsid;
} save_area[SLB_NUM_BOLTED];
} ____cacheline_aligned;
#endif /* CONFIG_PPC_BOOK3S */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_LPPACA_H */