linux/arch/powerpc/kvm/e500mc.c
Mihai Caraman 188e267ce2 KVM: PPC: e500mc: Add support for single threaded vcpus on e6500 core
ePAPR represents hardware threads as cpu node properties in device tree.
So with existing QEMU, hardware threads are simply exposed as vcpus with
one hardware thread.

The e6500 core shares TLBs between hardware threads. Without tlb write
conditional instruction, the Linux kernel uses per core mechanisms to
protect against duplicate TLB entries.

The guest is unable to detect real siblings threads, so it can't use the
TLB protection mechanism. An alternative solution is to use the hypervisor
to allocate different lpids to guest's vcpus that runs simultaneous on real
siblings threads. On systems with two threads per core this patch halves
the size of the lpid pool that the allocator sees and use two lpids per VM.
Use even numbers to speedup vcpu lpid computation with consecutive lpids
per VM: vm1 will use lpids 2 and 3, vm2 lpids 4 and 5, and so on.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: fix spelling]
Signed-off-by: Alexander Graf <agraf@suse.de>
2014-09-22 10:11:35 +02:00

434 lines
10 KiB
C

/*
* Copyright (C) 2010,2012 Freescale Semiconductor, Inc. All rights reserved.
*
* Author: Varun Sethi, <varun.sethi@freescale.com>
*
* Description:
* This file is derived from arch/powerpc/kvm/e500.c,
* by Yu Liu <yu.liu@freescale.com>.
*
* 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.
*/
#include <linux/kvm_host.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <asm/reg.h>
#include <asm/cputable.h>
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
#include <asm/dbell.h>
#include "booke.h"
#include "e500.h"
void kvmppc_set_pending_interrupt(struct kvm_vcpu *vcpu, enum int_class type)
{
enum ppc_dbell dbell_type;
unsigned long tag;
switch (type) {
case INT_CLASS_NONCRIT:
dbell_type = PPC_G_DBELL;
break;
case INT_CLASS_CRIT:
dbell_type = PPC_G_DBELL_CRIT;
break;
case INT_CLASS_MC:
dbell_type = PPC_G_DBELL_MC;
break;
default:
WARN_ONCE(1, "%s: unknown int type %d\n", __func__, type);
return;
}
preempt_disable();
tag = PPC_DBELL_LPID(get_lpid(vcpu)) | vcpu->vcpu_id;
mb();
ppc_msgsnd(dbell_type, 0, tag);
preempt_enable();
}
/* gtlbe must not be mapped by more than one host tlb entry */
void kvmppc_e500_tlbil_one(struct kvmppc_vcpu_e500 *vcpu_e500,
struct kvm_book3e_206_tlb_entry *gtlbe)
{
unsigned int tid, ts;
gva_t eaddr;
u32 val;
unsigned long flags;
ts = get_tlb_ts(gtlbe);
tid = get_tlb_tid(gtlbe);
/* We search the host TLB to invalidate its shadow TLB entry */
val = (tid << 16) | ts;
eaddr = get_tlb_eaddr(gtlbe);
local_irq_save(flags);
mtspr(SPRN_MAS6, val);
mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(&vcpu_e500->vcpu));
asm volatile("tlbsx 0, %[eaddr]\n" : : [eaddr] "r" (eaddr));
val = mfspr(SPRN_MAS1);
if (val & MAS1_VALID) {
mtspr(SPRN_MAS1, val & ~MAS1_VALID);
asm volatile("tlbwe");
}
mtspr(SPRN_MAS5, 0);
/* NOTE: tlbsx also updates mas8, so clear it for host tlbwe */
mtspr(SPRN_MAS8, 0);
isync();
local_irq_restore(flags);
}
void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500 *vcpu_e500)
{
unsigned long flags;
local_irq_save(flags);
mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(&vcpu_e500->vcpu));
asm volatile("tlbilxlpid");
mtspr(SPRN_MAS5, 0);
local_irq_restore(flags);
}
void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid)
{
vcpu->arch.pid = pid;
}
void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 old_msr)
{
}
/* We use two lpids per VM */
static DEFINE_PER_CPU(struct kvm_vcpu *[KVMPPC_NR_LPIDS], last_vcpu_of_lpid);
static void kvmppc_core_vcpu_load_e500mc(struct kvm_vcpu *vcpu, int cpu)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
kvmppc_booke_vcpu_load(vcpu, cpu);
mtspr(SPRN_LPID, get_lpid(vcpu));
mtspr(SPRN_EPCR, vcpu->arch.shadow_epcr);
mtspr(SPRN_GPIR, vcpu->vcpu_id);
mtspr(SPRN_MSRP, vcpu->arch.shadow_msrp);
vcpu->arch.eplc = EPC_EGS | (get_lpid(vcpu) << EPC_ELPID_SHIFT);
vcpu->arch.epsc = vcpu->arch.eplc;
mtspr(SPRN_EPLC, vcpu->arch.eplc);
mtspr(SPRN_EPSC, vcpu->arch.epsc);
mtspr(SPRN_GIVPR, vcpu->arch.ivpr);
mtspr(SPRN_GIVOR2, vcpu->arch.ivor[BOOKE_IRQPRIO_DATA_STORAGE]);
mtspr(SPRN_GIVOR8, vcpu->arch.ivor[BOOKE_IRQPRIO_SYSCALL]);
mtspr(SPRN_GSPRG0, (unsigned long)vcpu->arch.shared->sprg0);
mtspr(SPRN_GSPRG1, (unsigned long)vcpu->arch.shared->sprg1);
mtspr(SPRN_GSPRG2, (unsigned long)vcpu->arch.shared->sprg2);
mtspr(SPRN_GSPRG3, (unsigned long)vcpu->arch.shared->sprg3);
mtspr(SPRN_GSRR0, vcpu->arch.shared->srr0);
mtspr(SPRN_GSRR1, vcpu->arch.shared->srr1);
mtspr(SPRN_GEPR, vcpu->arch.epr);
mtspr(SPRN_GDEAR, vcpu->arch.shared->dar);
mtspr(SPRN_GESR, vcpu->arch.shared->esr);
if (vcpu->arch.oldpir != mfspr(SPRN_PIR) ||
__get_cpu_var(last_vcpu_of_lpid)[get_lpid(vcpu)] != vcpu) {
kvmppc_e500_tlbil_all(vcpu_e500);
__get_cpu_var(last_vcpu_of_lpid)[get_lpid(vcpu)] = vcpu;
}
}
static void kvmppc_core_vcpu_put_e500mc(struct kvm_vcpu *vcpu)
{
vcpu->arch.eplc = mfspr(SPRN_EPLC);
vcpu->arch.epsc = mfspr(SPRN_EPSC);
vcpu->arch.shared->sprg0 = mfspr(SPRN_GSPRG0);
vcpu->arch.shared->sprg1 = mfspr(SPRN_GSPRG1);
vcpu->arch.shared->sprg2 = mfspr(SPRN_GSPRG2);
vcpu->arch.shared->sprg3 = mfspr(SPRN_GSPRG3);
vcpu->arch.shared->srr0 = mfspr(SPRN_GSRR0);
vcpu->arch.shared->srr1 = mfspr(SPRN_GSRR1);
vcpu->arch.epr = mfspr(SPRN_GEPR);
vcpu->arch.shared->dar = mfspr(SPRN_GDEAR);
vcpu->arch.shared->esr = mfspr(SPRN_GESR);
vcpu->arch.oldpir = mfspr(SPRN_PIR);
kvmppc_booke_vcpu_put(vcpu);
}
int kvmppc_core_check_processor_compat(void)
{
int r;
if (strcmp(cur_cpu_spec->cpu_name, "e500mc") == 0)
r = 0;
else if (strcmp(cur_cpu_spec->cpu_name, "e5500") == 0)
r = 0;
else
r = -ENOTSUPP;
return r;
}
int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
vcpu->arch.shadow_epcr = SPRN_EPCR_DSIGS | SPRN_EPCR_DGTMI | \
SPRN_EPCR_DUVD;
#ifdef CONFIG_64BIT
vcpu->arch.shadow_epcr |= SPRN_EPCR_ICM;
#endif
vcpu->arch.shadow_msrp = MSRP_UCLEP | MSRP_PMMP;
vcpu->arch.pvr = mfspr(SPRN_PVR);
vcpu_e500->svr = mfspr(SPRN_SVR);
vcpu->arch.cpu_type = KVM_CPU_E500MC;
return 0;
}
static int kvmppc_core_get_sregs_e500mc(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
sregs->u.e.features |= KVM_SREGS_E_ARCH206_MMU | KVM_SREGS_E_PM |
KVM_SREGS_E_PC;
sregs->u.e.impl_id = KVM_SREGS_E_IMPL_FSL;
sregs->u.e.impl.fsl.features = 0;
sregs->u.e.impl.fsl.svr = vcpu_e500->svr;
sregs->u.e.impl.fsl.hid0 = vcpu_e500->hid0;
sregs->u.e.impl.fsl.mcar = vcpu_e500->mcar;
kvmppc_get_sregs_e500_tlb(vcpu, sregs);
sregs->u.e.ivor_high[3] =
vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR];
sregs->u.e.ivor_high[4] = vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL];
sregs->u.e.ivor_high[5] = vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL_CRIT];
return kvmppc_get_sregs_ivor(vcpu, sregs);
}
static int kvmppc_core_set_sregs_e500mc(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
int ret;
if (sregs->u.e.impl_id == KVM_SREGS_E_IMPL_FSL) {
vcpu_e500->svr = sregs->u.e.impl.fsl.svr;
vcpu_e500->hid0 = sregs->u.e.impl.fsl.hid0;
vcpu_e500->mcar = sregs->u.e.impl.fsl.mcar;
}
ret = kvmppc_set_sregs_e500_tlb(vcpu, sregs);
if (ret < 0)
return ret;
if (!(sregs->u.e.features & KVM_SREGS_E_IVOR))
return 0;
if (sregs->u.e.features & KVM_SREGS_E_PM) {
vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR] =
sregs->u.e.ivor_high[3];
}
if (sregs->u.e.features & KVM_SREGS_E_PC) {
vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL] =
sregs->u.e.ivor_high[4];
vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL_CRIT] =
sregs->u.e.ivor_high[5];
}
return kvmppc_set_sregs_ivor(vcpu, sregs);
}
static int kvmppc_get_one_reg_e500mc(struct kvm_vcpu *vcpu, u64 id,
union kvmppc_one_reg *val)
{
int r = 0;
switch (id) {
case KVM_REG_PPC_SPRG9:
*val = get_reg_val(id, vcpu->arch.sprg9);
break;
default:
r = kvmppc_get_one_reg_e500_tlb(vcpu, id, val);
}
return r;
}
static int kvmppc_set_one_reg_e500mc(struct kvm_vcpu *vcpu, u64 id,
union kvmppc_one_reg *val)
{
int r = 0;
switch (id) {
case KVM_REG_PPC_SPRG9:
vcpu->arch.sprg9 = set_reg_val(id, *val);
break;
default:
r = kvmppc_set_one_reg_e500_tlb(vcpu, id, val);
}
return r;
}
static struct kvm_vcpu *kvmppc_core_vcpu_create_e500mc(struct kvm *kvm,
unsigned int id)
{
struct kvmppc_vcpu_e500 *vcpu_e500;
struct kvm_vcpu *vcpu;
int err;
vcpu_e500 = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
if (!vcpu_e500) {
err = -ENOMEM;
goto out;
}
vcpu = &vcpu_e500->vcpu;
/* Invalid PIR value -- this LPID dosn't have valid state on any cpu */
vcpu->arch.oldpir = 0xffffffff;
err = kvm_vcpu_init(vcpu, kvm, id);
if (err)
goto free_vcpu;
err = kvmppc_e500_tlb_init(vcpu_e500);
if (err)
goto uninit_vcpu;
vcpu->arch.shared = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
if (!vcpu->arch.shared)
goto uninit_tlb;
return vcpu;
uninit_tlb:
kvmppc_e500_tlb_uninit(vcpu_e500);
uninit_vcpu:
kvm_vcpu_uninit(vcpu);
free_vcpu:
kmem_cache_free(kvm_vcpu_cache, vcpu_e500);
out:
return ERR_PTR(err);
}
static void kvmppc_core_vcpu_free_e500mc(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
free_page((unsigned long)vcpu->arch.shared);
kvmppc_e500_tlb_uninit(vcpu_e500);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, vcpu_e500);
}
static int kvmppc_core_init_vm_e500mc(struct kvm *kvm)
{
int lpid;
lpid = kvmppc_alloc_lpid();
if (lpid < 0)
return lpid;
/*
* Use two lpids per VM on cores with two threads like e6500. Use
* even numbers to speedup vcpu lpid computation with consecutive lpids
* per VM. vm1 will use lpids 2 and 3, vm2 lpids 4 and 5, and so on.
*/
if (threads_per_core == 2)
lpid <<= 1;
kvm->arch.lpid = lpid;
return 0;
}
static void kvmppc_core_destroy_vm_e500mc(struct kvm *kvm)
{
int lpid = kvm->arch.lpid;
if (threads_per_core == 2)
lpid >>= 1;
kvmppc_free_lpid(lpid);
}
static struct kvmppc_ops kvm_ops_e500mc = {
.get_sregs = kvmppc_core_get_sregs_e500mc,
.set_sregs = kvmppc_core_set_sregs_e500mc,
.get_one_reg = kvmppc_get_one_reg_e500mc,
.set_one_reg = kvmppc_set_one_reg_e500mc,
.vcpu_load = kvmppc_core_vcpu_load_e500mc,
.vcpu_put = kvmppc_core_vcpu_put_e500mc,
.vcpu_create = kvmppc_core_vcpu_create_e500mc,
.vcpu_free = kvmppc_core_vcpu_free_e500mc,
.mmu_destroy = kvmppc_mmu_destroy_e500,
.init_vm = kvmppc_core_init_vm_e500mc,
.destroy_vm = kvmppc_core_destroy_vm_e500mc,
.emulate_op = kvmppc_core_emulate_op_e500,
.emulate_mtspr = kvmppc_core_emulate_mtspr_e500,
.emulate_mfspr = kvmppc_core_emulate_mfspr_e500,
};
static int __init kvmppc_e500mc_init(void)
{
int r;
r = kvmppc_booke_init();
if (r)
goto err_out;
/*
* Use two lpids per VM on dual threaded processors like e6500
* to workarround the lack of tlb write conditional instruction.
* Expose half the number of available hardware lpids to the lpid
* allocator.
*/
kvmppc_init_lpid(KVMPPC_NR_LPIDS/threads_per_core);
kvmppc_claim_lpid(0); /* host */
r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
if (r)
goto err_out;
kvm_ops_e500mc.owner = THIS_MODULE;
kvmppc_pr_ops = &kvm_ops_e500mc;
err_out:
return r;
}
static void __exit kvmppc_e500mc_exit(void)
{
kvmppc_pr_ops = NULL;
kvmppc_booke_exit();
}
module_init(kvmppc_e500mc_init);
module_exit(kvmppc_e500mc_exit);
MODULE_ALIAS_MISCDEV(KVM_MINOR);
MODULE_ALIAS("devname:kvm");