blob: fc6bb9630a9c1aa33c2d2d862947a51d40872d70 [file] [log] [blame]
/*
* Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.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/cpu.h>
#include <linux/kvm_host.h>
#include <linux/preempt.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/sizes.h>
#include <linux/cma.h>
#include <linux/bitops.h>
#include <asm/asm-prototypes.h>
#include <asm/cputable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/archrandom.h>
#include <asm/xics.h>
#include <asm/xive.h>
#include <asm/dbell.h>
#include <asm/cputhreads.h>
#include <asm/io.h>
#include <asm/opal.h>
#include <asm/smp.h>
#define KVM_CMA_CHUNK_ORDER 18
#include "book3s_xics.h"
#include "book3s_xive.h"
/*
* The XIVE module will populate these when it loads
*/
unsigned long (*__xive_vm_h_xirr)(struct kvm_vcpu *vcpu);
unsigned long (*__xive_vm_h_ipoll)(struct kvm_vcpu *vcpu, unsigned long server);
int (*__xive_vm_h_ipi)(struct kvm_vcpu *vcpu, unsigned long server,
unsigned long mfrr);
int (*__xive_vm_h_cppr)(struct kvm_vcpu *vcpu, unsigned long cppr);
int (*__xive_vm_h_eoi)(struct kvm_vcpu *vcpu, unsigned long xirr);
EXPORT_SYMBOL_GPL(__xive_vm_h_xirr);
EXPORT_SYMBOL_GPL(__xive_vm_h_ipoll);
EXPORT_SYMBOL_GPL(__xive_vm_h_ipi);
EXPORT_SYMBOL_GPL(__xive_vm_h_cppr);
EXPORT_SYMBOL_GPL(__xive_vm_h_eoi);
/*
* Hash page table alignment on newer cpus(CPU_FTR_ARCH_206)
* should be power of 2.
*/
#define HPT_ALIGN_PAGES ((1 << 18) >> PAGE_SHIFT) /* 256k */
/*
* By default we reserve 5% of memory for hash pagetable allocation.
*/
static unsigned long kvm_cma_resv_ratio = 5;
static struct cma *kvm_cma;
static int __init early_parse_kvm_cma_resv(char *p)
{
pr_debug("%s(%s)\n", __func__, p);
if (!p)
return -EINVAL;
return kstrtoul(p, 0, &kvm_cma_resv_ratio);
}
early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv);
struct page *kvm_alloc_hpt_cma(unsigned long nr_pages)
{
VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES),
false);
}
EXPORT_SYMBOL_GPL(kvm_alloc_hpt_cma);
void kvm_free_hpt_cma(struct page *page, unsigned long nr_pages)
{
cma_release(kvm_cma, page, nr_pages);
}
EXPORT_SYMBOL_GPL(kvm_free_hpt_cma);
/**
* kvm_cma_reserve() - reserve area for kvm hash pagetable
*
* This function reserves memory from early allocator. It should be
* called by arch specific code once the memblock allocator
* has been activated and all other subsystems have already allocated/reserved
* memory.
*/
void __init kvm_cma_reserve(void)
{
unsigned long align_size;
struct memblock_region *reg;
phys_addr_t selected_size = 0;
/*
* We need CMA reservation only when we are in HV mode
*/
if (!cpu_has_feature(CPU_FTR_HVMODE))
return;
/*
* We cannot use memblock_phys_mem_size() here, because
* memblock_analyze() has not been called yet.
*/
for_each_memblock(memory, reg)
selected_size += memblock_region_memory_end_pfn(reg) -
memblock_region_memory_base_pfn(reg);
selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;
if (selected_size) {
pr_debug("%s: reserving %ld MiB for global area\n", __func__,
(unsigned long)selected_size / SZ_1M);
align_size = HPT_ALIGN_PAGES << PAGE_SHIFT;
cma_declare_contiguous(0, selected_size, 0, align_size,
KVM_CMA_CHUNK_ORDER - PAGE_SHIFT, false, "kvm_cma",
&kvm_cma);
}
}
/*
* Real-mode H_CONFER implementation.
* We check if we are the only vcpu out of this virtual core
* still running in the guest and not ceded. If so, we pop up
* to the virtual-mode implementation; if not, just return to
* the guest.
*/
long int kvmppc_rm_h_confer(struct kvm_vcpu *vcpu, int target,
unsigned int yield_count)
{
struct kvmppc_vcore *vc = local_paca->kvm_hstate.kvm_vcore;
int ptid = local_paca->kvm_hstate.ptid;
int threads_running;
int threads_ceded;
int threads_conferring;
u64 stop = get_tb() + 10 * tb_ticks_per_usec;
int rv = H_SUCCESS; /* => don't yield */
set_bit(ptid, &vc->conferring_threads);
while ((get_tb() < stop) && !VCORE_IS_EXITING(vc)) {
threads_running = VCORE_ENTRY_MAP(vc);
threads_ceded = vc->napping_threads;
threads_conferring = vc->conferring_threads;
if ((threads_ceded | threads_conferring) == threads_running) {
rv = H_TOO_HARD; /* => do yield */
break;
}
}
clear_bit(ptid, &vc->conferring_threads);
return rv;
}
/*
* When running HV mode KVM we need to block certain operations while KVM VMs
* exist in the system. We use a counter of VMs to track this.
*
* One of the operations we need to block is onlining of secondaries, so we
* protect hv_vm_count with get/put_online_cpus().
*/
static atomic_t hv_vm_count;
void kvm_hv_vm_activated(void)
{
get_online_cpus();
atomic_inc(&hv_vm_count);
put_online_cpus();
}
EXPORT_SYMBOL_GPL(kvm_hv_vm_activated);
void kvm_hv_vm_deactivated(void)
{
get_online_cpus();
atomic_dec(&hv_vm_count);
put_online_cpus();
}
EXPORT_SYMBOL_GPL(kvm_hv_vm_deactivated);
bool kvm_hv_mode_active(void)
{
return atomic_read(&hv_vm_count) != 0;
}
extern int hcall_real_table[], hcall_real_table_end[];
int kvmppc_hcall_impl_hv_realmode(unsigned long cmd)
{
cmd /= 4;
if (cmd < hcall_real_table_end - hcall_real_table &&
hcall_real_table[cmd])
return 1;
return 0;
}
EXPORT_SYMBOL_GPL(kvmppc_hcall_impl_hv_realmode);
int kvmppc_hwrng_present(void)
{
return powernv_hwrng_present();
}
EXPORT_SYMBOL_GPL(kvmppc_hwrng_present);
long kvmppc_h_random(struct kvm_vcpu *vcpu)
{
int r;
/* Only need to do the expensive mfmsr() on radix */
if (kvm_is_radix(vcpu->kvm) && (mfmsr() & MSR_IR))
r = powernv_get_random_long(&vcpu->arch.regs.gpr[4]);
else
r = powernv_get_random_real_mode(&vcpu->arch.regs.gpr[4]);
if (r)
return H_SUCCESS;
return H_HARDWARE;
}
/*
* Send an interrupt or message to another CPU.
* The caller needs to include any barrier needed to order writes
* to memory vs. the IPI/message.
*/
void kvmhv_rm_send_ipi(int cpu)
{
void __iomem *xics_phys;
unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER);
/* On POWER9 we can use msgsnd for any destination cpu. */
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
msg |= get_hard_smp_processor_id(cpu);
__asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
return;
}
/* On POWER8 for IPIs to threads in the same core, use msgsnd. */
if (cpu_has_feature(CPU_FTR_ARCH_207S) &&
cpu_first_thread_sibling(cpu) ==
cpu_first_thread_sibling(raw_smp_processor_id())) {
msg |= cpu_thread_in_core(cpu);
__asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
return;
}
/* We should never reach this */
if (WARN_ON_ONCE(xive_enabled()))
return;
/* Else poke the target with an IPI */
xics_phys = paca_ptrs[cpu]->kvm_hstate.xics_phys;
if (xics_phys)
__raw_rm_writeb(IPI_PRIORITY, xics_phys + XICS_MFRR);
else
opal_int_set_mfrr(get_hard_smp_processor_id(cpu), IPI_PRIORITY);
}
/*
* The following functions are called from the assembly code
* in book3s_hv_rmhandlers.S.
*/
static void kvmhv_interrupt_vcore(struct kvmppc_vcore *vc, int active)
{
int cpu = vc->pcpu;
/* Order setting of exit map vs. msgsnd/IPI */
smp_mb();
for (; active; active >>= 1, ++cpu)
if (active & 1)
kvmhv_rm_send_ipi(cpu);
}
void kvmhv_commence_exit(int trap)
{
struct kvmppc_vcore *vc = local_paca->kvm_hstate.kvm_vcore;
int ptid = local_paca->kvm_hstate.ptid;
struct kvm_split_mode *sip = local_paca->kvm_hstate.kvm_split_mode;
int me, ee, i, t;
int cpu0;
/* Set our bit in the threads-exiting-guest map in the 0xff00
bits of vcore->entry_exit_map */
me = 0x100 << ptid;
do {
ee = vc->entry_exit_map;
} while (cmpxchg(&vc->entry_exit_map, ee, ee | me) != ee);
/* Are we the first here? */
if ((ee >> 8) != 0)
return;
/*
* Trigger the other threads in this vcore to exit the guest.
* If this is a hypervisor decrementer interrupt then they
* will be already on their way out of the guest.
*/
if (trap != BOOK3S_INTERRUPT_HV_DECREMENTER)
kvmhv_interrupt_vcore(vc, ee & ~(1 << ptid));
/*
* If we are doing dynamic micro-threading, interrupt the other
* subcores to pull them out of their guests too.
*/
if (!sip)
return;
for (i = 0; i < MAX_SUBCORES; ++i) {
vc = sip->vc[i];
if (!vc)
break;
do {
ee = vc->entry_exit_map;
/* Already asked to exit? */
if ((ee >> 8) != 0)
break;
} while (cmpxchg(&vc->entry_exit_map, ee,
ee | VCORE_EXIT_REQ) != ee);
if ((ee >> 8) == 0)
kvmhv_interrupt_vcore(vc, ee);
}
/*
* On POWER9 when running a HPT guest on a radix host (sip != NULL),
* we have to interrupt inactive CPU threads to get them to
* restore the host LPCR value.
*/
if (sip->lpcr_req) {
if (cmpxchg(&sip->do_restore, 0, 1) == 0) {
vc = local_paca->kvm_hstate.kvm_vcore;
cpu0 = vc->pcpu + ptid - local_paca->kvm_hstate.tid;
for (t = 1; t < threads_per_core; ++t) {
if (sip->napped[t])
kvmhv_rm_send_ipi(cpu0 + t);
}
}
}
}
struct kvmppc_host_rm_ops *kvmppc_host_rm_ops_hv;
EXPORT_SYMBOL_GPL(kvmppc_host_rm_ops_hv);
#ifdef CONFIG_KVM_XICS
static struct kvmppc_irq_map *get_irqmap(struct kvmppc_passthru_irqmap *pimap,
u32 xisr)
{
int i;
/*
* We access the mapped array here without a lock. That
* is safe because we never reduce the number of entries
* in the array and we never change the v_hwirq field of
* an entry once it is set.
*
* We have also carefully ordered the stores in the writer
* and the loads here in the reader, so that if we find a matching
* hwirq here, the associated GSI and irq_desc fields are valid.
*/
for (i = 0; i < pimap->n_mapped; i++) {
if (xisr == pimap->mapped[i].r_hwirq) {
/*
* Order subsequent reads in the caller to serialize
* with the writer.
*/
smp_rmb();
return &pimap->mapped[i];
}
}
return NULL;
}
/*
* If we have an interrupt that's not an IPI, check if we have a
* passthrough adapter and if so, check if this external interrupt
* is for the adapter.
* We will attempt to deliver the IRQ directly to the target VCPU's
* ICP, the virtual ICP (based on affinity - the xive value in ICS).
*
* If the delivery fails or if this is not for a passthrough adapter,
* return to the host to handle this interrupt. We earlier
* saved a copy of the XIRR in the PACA, it will be picked up by
* the host ICP driver.
*/
static int kvmppc_check_passthru(u32 xisr, __be32 xirr, bool *again)
{
struct kvmppc_passthru_irqmap *pimap;
struct kvmppc_irq_map *irq_map;
struct kvm_vcpu *vcpu;
vcpu = local_paca->kvm_hstate.kvm_vcpu;
if (!vcpu)
return 1;
pimap = kvmppc_get_passthru_irqmap(vcpu->kvm);
if (!pimap)
return 1;
irq_map = get_irqmap(pimap, xisr);
if (!irq_map)
return 1;
/* We're handling this interrupt, generic code doesn't need to */
local_paca->kvm_hstate.saved_xirr = 0;
return kvmppc_deliver_irq_passthru(vcpu, xirr, irq_map, pimap, again);
}
#else
static inline int kvmppc_check_passthru(u32 xisr, __be32 xirr, bool *again)
{
return 1;
}
#endif
/*
* Determine what sort of external interrupt is pending (if any).
* Returns:
* 0 if no interrupt is pending
* 1 if an interrupt is pending that needs to be handled by the host
* 2 Passthrough that needs completion in the host
* -1 if there was a guest wakeup IPI (which has now been cleared)
* -2 if there is PCI passthrough external interrupt that was handled
*/
static long kvmppc_read_one_intr(bool *again);
long kvmppc_read_intr(void)
{
long ret = 0;
long rc;
bool again;
if (xive_enabled())
return 1;
do {
again = false;
rc = kvmppc_read_one_intr(&again);
if (rc && (ret == 0 || rc > ret))
ret = rc;
} while (again);
return ret;
}
static long kvmppc_read_one_intr(bool *again)
{
void __iomem *xics_phys;
u32 h_xirr;
__be32 xirr;
u32 xisr;
u8 host_ipi;
int64_t rc;
if (xive_enabled())
return 1;
/* see if a host IPI is pending */
host_ipi = local_paca->kvm_hstate.host_ipi;
if (host_ipi)
return 1;
/* Now read the interrupt from the ICP */
xics_phys = local_paca->kvm_hstate.xics_phys;
rc = 0;
if (!xics_phys)
rc = opal_int_get_xirr(&xirr, false);
else
xirr = __raw_rm_readl(xics_phys + XICS_XIRR);
if (rc < 0)
return 1;
/*
* Save XIRR for later. Since we get control in reverse endian
* on LE systems, save it byte reversed and fetch it back in
* host endian. Note that xirr is the value read from the
* XIRR register, while h_xirr is the host endian version.
*/
h_xirr = be32_to_cpu(xirr);
local_paca->kvm_hstate.saved_xirr = h_xirr;
xisr = h_xirr & 0xffffff;
/*
* Ensure that the store/load complete to guarantee all side
* effects of loading from XIRR has completed
*/
smp_mb();
/* if nothing pending in the ICP */
if (!xisr)
return 0;
/* We found something in the ICP...
*
* If it is an IPI, clear the MFRR and EOI it.
*/
if (xisr == XICS_IPI) {
rc = 0;
if (xics_phys) {
__raw_rm_writeb(0xff, xics_phys + XICS_MFRR);
__raw_rm_writel(xirr, xics_phys + XICS_XIRR);
} else {
opal_int_set_mfrr(hard_smp_processor_id(), 0xff);
rc = opal_int_eoi(h_xirr);
}
/* If rc > 0, there is another interrupt pending */
*again = rc > 0;
/*
* Need to ensure side effects of above stores
* complete before proceeding.
*/
smp_mb();
/*
* We need to re-check host IPI now in case it got set in the
* meantime. If it's clear, we bounce the interrupt to the
* guest
*/
host_ipi = local_paca->kvm_hstate.host_ipi;
if (unlikely(host_ipi != 0)) {
/* We raced with the host,
* we need to resend that IPI, bummer
*/
if (xics_phys)
__raw_rm_writeb(IPI_PRIORITY,
xics_phys + XICS_MFRR);
else
opal_int_set_mfrr(hard_smp_processor_id(),
IPI_PRIORITY);
/* Let side effects complete */
smp_mb();
return 1;
}
/* OK, it's an IPI for us */
local_paca->kvm_hstate.saved_xirr = 0;
return -1;
}
return kvmppc_check_passthru(xisr, xirr, again);
}
#ifdef CONFIG_KVM_XICS
static inline bool is_rm(void)
{
return !(mfmsr() & MSR_DR);
}
unsigned long kvmppc_rm_h_xirr(struct kvm_vcpu *vcpu)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_xirr(vcpu);
if (unlikely(!__xive_vm_h_xirr))
return H_NOT_AVAILABLE;
return __xive_vm_h_xirr(vcpu);
} else
return xics_rm_h_xirr(vcpu);
}
unsigned long kvmppc_rm_h_xirr_x(struct kvm_vcpu *vcpu)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
vcpu->arch.regs.gpr[5] = get_tb();
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_xirr(vcpu);
if (unlikely(!__xive_vm_h_xirr))
return H_NOT_AVAILABLE;
return __xive_vm_h_xirr(vcpu);
} else
return xics_rm_h_xirr(vcpu);
}
unsigned long kvmppc_rm_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_ipoll(vcpu, server);
if (unlikely(!__xive_vm_h_ipoll))
return H_NOT_AVAILABLE;
return __xive_vm_h_ipoll(vcpu, server);
} else
return H_TOO_HARD;
}
int kvmppc_rm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
unsigned long mfrr)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_ipi(vcpu, server, mfrr);
if (unlikely(!__xive_vm_h_ipi))
return H_NOT_AVAILABLE;
return __xive_vm_h_ipi(vcpu, server, mfrr);
} else
return xics_rm_h_ipi(vcpu, server, mfrr);
}
int kvmppc_rm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_cppr(vcpu, cppr);
if (unlikely(!__xive_vm_h_cppr))
return H_NOT_AVAILABLE;
return __xive_vm_h_cppr(vcpu, cppr);
} else
return xics_rm_h_cppr(vcpu, cppr);
}
int kvmppc_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_eoi(vcpu, xirr);
if (unlikely(!__xive_vm_h_eoi))
return H_NOT_AVAILABLE;
return __xive_vm_h_eoi(vcpu, xirr);
} else
return xics_rm_h_eoi(vcpu, xirr);
}
#endif /* CONFIG_KVM_XICS */
void kvmppc_bad_interrupt(struct pt_regs *regs)
{
/*
* 100 could happen at any time, 200 can happen due to invalid real
* address access for example (or any time due to a hardware problem).
*/
if (TRAP(regs) == 0x100) {
get_paca()->in_nmi++;
system_reset_exception(regs);
get_paca()->in_nmi--;
} else if (TRAP(regs) == 0x200) {
machine_check_exception(regs);
} else {
die("Bad interrupt in KVM entry/exit code", regs, SIGABRT);
}
panic("Bad KVM trap");
}
/*
* Functions used to switch LPCR HR and UPRT bits on all threads
* when entering and exiting HPT guests on a radix host.
*/
#define PHASE_REALMODE 1 /* in real mode */
#define PHASE_SET_LPCR 2 /* have set LPCR */
#define PHASE_OUT_OF_GUEST 4 /* have finished executing in guest */
#define PHASE_RESET_LPCR 8 /* have reset LPCR to host value */
#define ALL(p) (((p) << 24) | ((p) << 16) | ((p) << 8) | (p))
static void wait_for_sync(struct kvm_split_mode *sip, int phase)
{
int thr = local_paca->kvm_hstate.tid;
sip->lpcr_sync.phase[thr] |= phase;
phase = ALL(phase);
while ((sip->lpcr_sync.allphases & phase) != phase) {
HMT_low();
barrier();
}
HMT_medium();
}
void kvmhv_p9_set_lpcr(struct kvm_split_mode *sip)
{
unsigned long rb, set;
/* wait for every other thread to get to real mode */
wait_for_sync(sip, PHASE_REALMODE);
/* Set LPCR and LPIDR */
mtspr(SPRN_LPCR, sip->lpcr_req);
mtspr(SPRN_LPID, sip->lpidr_req);
isync();
/* Invalidate the TLB on thread 0 */
if (local_paca->kvm_hstate.tid == 0) {
sip->do_set = 0;
asm volatile("ptesync" : : : "memory");
for (set = 0; set < POWER9_TLB_SETS_RADIX; ++set) {
rb = TLBIEL_INVAL_SET_LPID +
(set << TLBIEL_INVAL_SET_SHIFT);
asm volatile(PPC_TLBIEL(%0, %1, 0, 0, 0) : :
"r" (rb), "r" (0));
}
asm volatile("ptesync" : : : "memory");
}
/* indicate that we have done so and wait for others */
wait_for_sync(sip, PHASE_SET_LPCR);
/* order read of sip->lpcr_sync.allphases vs. sip->do_set */
smp_rmb();
}
/*
* Called when a thread that has been in the guest needs
* to reload the host LPCR value - but only on POWER9 when
* running a HPT guest on a radix host.
*/
void kvmhv_p9_restore_lpcr(struct kvm_split_mode *sip)
{
/* we're out of the guest... */
wait_for_sync(sip, PHASE_OUT_OF_GUEST);
mtspr(SPRN_LPID, 0);
mtspr(SPRN_LPCR, sip->host_lpcr);
isync();
if (local_paca->kvm_hstate.tid == 0) {
sip->do_restore = 0;
smp_wmb(); /* order store of do_restore vs. phase */
}
wait_for_sync(sip, PHASE_RESET_LPCR);
smp_mb();
local_paca->kvm_hstate.kvm_split_mode = NULL;
}