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0cda69dd7cd64fdd54bdf584b5d6ba53767ba422
android_kernel_xiaomi_sm8450/arch/powerpc/include/asm/kvm_book3s.h
Suraj Jitindar Singh 0cda69dd7c KVM: PPC: Book3S HV: Implement halt polling 
This patch introduces new halt polling functionality into the kvm_hv kernel
module. When a vcore is idle it will poll for some period of time before
scheduling itself out.

When all of the runnable vcpus on a vcore have ceded (and thus the vcore is
idle) we schedule ourselves out to allow something else to run. In the
event that we need to wake up very quickly (for example an interrupt
arrives), we are required to wait until we get scheduled again.

Implement halt polling so that when a vcore is idle, and before scheduling
ourselves, we poll for vcpus in the runnable_threads list which have
pending exceptions or which leave the ceded state. If we poll successfully
then we can get back into the guest very quickly without ever scheduling
ourselves, otherwise we schedule ourselves out as before.

There exists generic halt_polling code in virt/kvm_main.c, however on
powerpc the polling conditions are different to the generic case. It would
be nice if we could just implement an arch specific kvm_check_block()
function, but there is still other arch specific things which need to be
done for kvm_hv (for example manipulating vcore states) which means that a
separate implementation is the best option.

Testing of this patch with a TCP round robin test between two guests with
virtio network interfaces has found a decrease in round trip time of ~15us
on average. A performance gain is only seen when going out of and
back into the guest often and quickly, otherwise there is no net benefit
from the polling. The polling interval is adjusted such that when we are
often scheduled out for long periods of time it is reduced, and when we
often poll successfully it is increased. The rate at which the polling
interval increases or decreases, and the maximum polling interval, can
be set through module parameters.

Based on the implementation in the generic kvm module by Wanpeng Li and
Paolo Bonzini, and on direction from Paul Mackerras.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-09-08 12:21:45 +10:00

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/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright SUSE Linux Products GmbH 2009
*
* Authors: Alexander Graf <agraf@suse.de>
*/
#ifndef __ASM_KVM_BOOK3S_H__
#define __ASM_KVM_BOOK3S_H__
#include <linux/types.h>
#include <linux/kvm_host.h>
#include <asm/kvm_book3s_asm.h>
struct kvmppc_bat {
u64 raw;
u32 bepi;
u32 bepi_mask;
u32 brpn;
u8 wimg;
u8 pp;
bool vs : 1;
bool vp : 1;
};
struct kvmppc_sid_map {
u64 guest_vsid;
u64 guest_esid;
u64 host_vsid;
bool valid : 1;
};
#define SID_MAP_BITS 9
#define SID_MAP_NUM (1 << SID_MAP_BITS)
#define SID_MAP_MASK (SID_MAP_NUM - 1)
#ifdef CONFIG_PPC_BOOK3S_64
#define SID_CONTEXTS 1
#else
#define SID_CONTEXTS 128
#define VSID_POOL_SIZE (SID_CONTEXTS * 16)
#endif
struct hpte_cache {
struct hlist_node list_pte;
struct hlist_node list_pte_long;
struct hlist_node list_vpte;
struct hlist_node list_vpte_long;
#ifdef CONFIG_PPC_BOOK3S_64
struct hlist_node list_vpte_64k;
#endif
struct rcu_head rcu_head;
u64 host_vpn;
u64 pfn;
ulong slot;
struct kvmppc_pte pte;
int pagesize;
};
/*
* Struct for a virtual core.
* Note: entry_exit_map combines a bitmap of threads that have entered
* in the bottom 8 bits and a bitmap of threads that have exited in the
* next 8 bits. This is so that we can atomically set the entry bit
* iff the exit map is 0 without taking a lock.
*/
struct kvmppc_vcore {
int n_runnable;
int num_threads;
int entry_exit_map;
int napping_threads;
int first_vcpuid;
u16 pcpu;
u16 last_cpu;
u8 vcore_state;
u8 in_guest;
struct kvmppc_vcore *master_vcore;
struct kvm_vcpu *runnable_threads[MAX_SMT_THREADS];
struct list_head preempt_list;
spinlock_t lock;
struct swait_queue_head wq;
spinlock_t stoltb_lock; /* protects stolen_tb and preempt_tb */
u64 stolen_tb;
u64 preempt_tb;
struct kvm_vcpu *runner;
struct kvm *kvm;
u64 tb_offset; /* guest timebase - host timebase */
ulong lpcr;
u32 arch_compat;
ulong pcr;
ulong dpdes; /* doorbell state (POWER8) */
ulong conferring_threads;
unsigned int halt_poll_ns;
};
struct kvmppc_vcpu_book3s {
struct kvmppc_sid_map sid_map[SID_MAP_NUM];
struct {
u64 esid;
u64 vsid;
} slb_shadow[64];
u8 slb_shadow_max;
struct kvmppc_bat ibat[8];
struct kvmppc_bat dbat[8];
u64 hid[6];
u64 gqr[8];
u64 sdr1;
u64 hior;
u64 msr_mask;
#ifdef CONFIG_PPC_BOOK3S_32
u32 vsid_pool[VSID_POOL_SIZE];
u32 vsid_next;
#else
u64 proto_vsid_first;
u64 proto_vsid_max;
u64 proto_vsid_next;
#endif
int context_id[SID_CONTEXTS];
bool hior_explicit; /* HIOR is set by ioctl, not PVR */
struct hlist_head hpte_hash_pte[HPTEG_HASH_NUM_PTE];
struct hlist_head hpte_hash_pte_long[HPTEG_HASH_NUM_PTE_LONG];
struct hlist_head hpte_hash_vpte[HPTEG_HASH_NUM_VPTE];
struct hlist_head hpte_hash_vpte_long[HPTEG_HASH_NUM_VPTE_LONG];
#ifdef CONFIG_PPC_BOOK3S_64
struct hlist_head hpte_hash_vpte_64k[HPTEG_HASH_NUM_VPTE_64K];
#endif
int hpte_cache_count;
spinlock_t mmu_lock;
};
#define VSID_REAL 0x07ffffffffc00000ULL
#define VSID_BAT 0x07ffffffffb00000ULL
#define VSID_64K 0x0800000000000000ULL
#define VSID_1T 0x1000000000000000ULL
#define VSID_REAL_DR 0x2000000000000000ULL
#define VSID_REAL_IR 0x4000000000000000ULL
#define VSID_PR 0x8000000000000000ULL
extern void kvmppc_mmu_pte_flush(struct kvm_vcpu *vcpu, ulong ea, ulong ea_mask);
extern void kvmppc_mmu_pte_vflush(struct kvm_vcpu *vcpu, u64 vp, u64 vp_mask);
extern void kvmppc_mmu_pte_pflush(struct kvm_vcpu *vcpu, ulong pa_start, ulong pa_end);
extern void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 new_msr);
extern void kvmppc_mmu_book3s_64_init(struct kvm_vcpu *vcpu);
extern void kvmppc_mmu_book3s_32_init(struct kvm_vcpu *vcpu);
extern void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu);
extern int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte,
bool iswrite);
extern void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte);
extern int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr);
extern void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong eaddr, ulong seg_size);
extern void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu);
extern int kvmppc_book3s_hv_page_fault(struct kvm_run *run,
struct kvm_vcpu *vcpu, unsigned long addr,
unsigned long status);
extern long kvmppc_hv_find_lock_hpte(struct kvm *kvm, gva_t eaddr,
unsigned long slb_v, unsigned long valid);
extern void kvmppc_mmu_hpte_cache_map(struct kvm_vcpu *vcpu, struct hpte_cache *pte);
extern struct hpte_cache *kvmppc_mmu_hpte_cache_next(struct kvm_vcpu *vcpu);
extern void kvmppc_mmu_hpte_cache_free(struct hpte_cache *pte);
extern void kvmppc_mmu_hpte_destroy(struct kvm_vcpu *vcpu);
extern int kvmppc_mmu_hpte_init(struct kvm_vcpu *vcpu);
extern void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte);
extern int kvmppc_mmu_hpte_sysinit(void);
extern void kvmppc_mmu_hpte_sysexit(void);
extern int kvmppc_mmu_hv_init(void);
extern int kvmppc_book3s_hcall_implemented(struct kvm *kvm, unsigned long hc);
/* XXX remove this export when load_last_inst() is generic */
extern int kvmppc_ld(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr, bool data);
extern void kvmppc_book3s_queue_irqprio(struct kvm_vcpu *vcpu, unsigned int vec);
extern void kvmppc_book3s_dequeue_irqprio(struct kvm_vcpu *vcpu,
unsigned int vec);
extern void kvmppc_inject_interrupt(struct kvm_vcpu *vcpu, int vec, u64 flags);
extern void kvmppc_set_bat(struct kvm_vcpu *vcpu, struct kvmppc_bat *bat,
bool upper, u32 val);
extern void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr);
extern int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu);
extern kvm_pfn_t kvmppc_gpa_to_pfn(struct kvm_vcpu *vcpu, gpa_t gpa,
bool writing, bool *writable);
extern void kvmppc_add_revmap_chain(struct kvm *kvm, struct revmap_entry *rev,
unsigned long *rmap, long pte_index, int realmode);
extern void kvmppc_update_rmap_change(unsigned long *rmap, unsigned long psize);
extern void kvmppc_invalidate_hpte(struct kvm *kvm, __be64 *hptep,
unsigned long pte_index);
void kvmppc_clear_ref_hpte(struct kvm *kvm, __be64 *hptep,
unsigned long pte_index);
extern void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long addr,
unsigned long *nb_ret);
extern void kvmppc_unpin_guest_page(struct kvm *kvm, void *addr,
unsigned long gpa, bool dirty);
extern long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
long pte_index, unsigned long pteh, unsigned long ptel,
pgd_t *pgdir, bool realmode, unsigned long *idx_ret);
extern long kvmppc_do_h_remove(struct kvm *kvm, unsigned long flags,
unsigned long pte_index, unsigned long avpn,
unsigned long *hpret);
extern long kvmppc_hv_get_dirty_log(struct kvm *kvm,
struct kvm_memory_slot *memslot, unsigned long *map);
extern void kvmppc_update_lpcr(struct kvm *kvm, unsigned long lpcr,
unsigned long mask);
extern void kvmppc_set_fscr(struct kvm_vcpu *vcpu, u64 fscr);
extern void kvmppc_entry_trampoline(void);
extern void kvmppc_hv_entry_trampoline(void);
extern u32 kvmppc_alignment_dsisr(struct kvm_vcpu *vcpu, unsigned int inst);
extern ulong kvmppc_alignment_dar(struct kvm_vcpu *vcpu, unsigned int inst);
extern int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd);
extern void kvmppc_pr_init_default_hcalls(struct kvm *kvm);
extern int kvmppc_hcall_impl_pr(unsigned long cmd);
extern int kvmppc_hcall_impl_hv_realmode(unsigned long cmd);
extern void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu,
struct kvm_vcpu *vcpu);
extern void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu,
struct kvmppc_book3s_shadow_vcpu *svcpu);
static inline struct kvmppc_vcpu_book3s *to_book3s(struct kvm_vcpu *vcpu)
{
return vcpu->arch.book3s;
}
/* Also add subarch specific defines */
#ifdef CONFIG_KVM_BOOK3S_32_HANDLER
#include <asm/kvm_book3s_32.h>
#endif
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
#include <asm/kvm_book3s_64.h>
#endif
static inline void kvmppc_set_gpr(struct kvm_vcpu *vcpu, int num, ulong val)
{
vcpu->arch.gpr[num] = val;
}
static inline ulong kvmppc_get_gpr(struct kvm_vcpu *vcpu, int num)
{
return vcpu->arch.gpr[num];
}
static inline void kvmppc_set_cr(struct kvm_vcpu *vcpu, u32 val)
{
vcpu->arch.cr = val;
}
static inline u32 kvmppc_get_cr(struct kvm_vcpu *vcpu)
{
return vcpu->arch.cr;
}
static inline void kvmppc_set_xer(struct kvm_vcpu *vcpu, ulong val)
{
vcpu->arch.xer = val;
}
static inline ulong kvmppc_get_xer(struct kvm_vcpu *vcpu)
{
return vcpu->arch.xer;
}
static inline void kvmppc_set_ctr(struct kvm_vcpu *vcpu, ulong val)
{
vcpu->arch.ctr = val;
}
static inline ulong kvmppc_get_ctr(struct kvm_vcpu *vcpu)
{
return vcpu->arch.ctr;
}
static inline void kvmppc_set_lr(struct kvm_vcpu *vcpu, ulong val)
{
vcpu->arch.lr = val;
}
static inline ulong kvmppc_get_lr(struct kvm_vcpu *vcpu)
{
return vcpu->arch.lr;
}
static inline void kvmppc_set_pc(struct kvm_vcpu *vcpu, ulong val)
{
vcpu->arch.pc = val;
}
static inline ulong kvmppc_get_pc(struct kvm_vcpu *vcpu)
{
return vcpu->arch.pc;
}
static inline u64 kvmppc_get_msr(struct kvm_vcpu *vcpu);
static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu)
{
return (kvmppc_get_msr(vcpu) & MSR_LE) != (MSR_KERNEL & MSR_LE);
}
static inline ulong kvmppc_get_fault_dar(struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault_dar;
}
static inline bool is_kvmppc_resume_guest(int r)
{
return (r == RESUME_GUEST || r == RESUME_GUEST_NV);
}
static inline bool is_kvmppc_hv_enabled(struct kvm *kvm);
static inline bool kvmppc_supports_magic_page(struct kvm_vcpu *vcpu)
{
/* Only PR KVM supports the magic page */
return !is_kvmppc_hv_enabled(vcpu->kvm);
}
extern int kvmppc_h_logical_ci_load(struct kvm_vcpu *vcpu);
extern int kvmppc_h_logical_ci_store(struct kvm_vcpu *vcpu);
/* Magic register values loaded into r3 and r4 before the 'sc' assembly
* instruction for the OSI hypercalls */
#define OSI_SC_MAGIC_R3 0x113724FA
#define OSI_SC_MAGIC_R4 0x77810F9B
#define INS_DCBZ 0x7c0007ec
/* TO = 31 for unconditional trap */
#define INS_TW 0x7fe00008
/* LPIDs we support with this build -- runtime limit may be lower */
#define KVMPPC_NR_LPIDS (LPID_RSVD + 1)
#define SPLIT_HACK_MASK 0xff000000
#define SPLIT_HACK_OFFS 0xfb000000
#endif /* __ASM_KVM_BOOK3S_H__ */
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