// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2011 Paul Mackerras, IBM Corp. <[email protected]>
*/
#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/cputable.h>
#include <asm/interrupt.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/machdep.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"
#include "book3s_hv.h"
/*
* 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;
phys_addr_t selected_size;
/*
* We need CMA reservation only when we are in HV mode
*/
if (!cpu_has_feature(CPU_FTR_HVMODE))
return;
selected_size = PAGE_ALIGN(memblock_phys_mem_size() * kvm_cma_resv_ratio / 100);
if (selected_size) {
pr_info("%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 cpus_read_lock/unlock().
*/
static atomic_t hv_vm_count;
void kvm_hv_vm_activated(void)
{
cpus_read_lock();
atomic_inc(&hv_vm_count);
cpus_read_unlock();
}
EXPORT_SYMBOL_GPL(kvm_hv_vm_activated);
void kvm_hv_vm_deactivated(void)
{
cpus_read_lock();
atomic_dec(&hv_vm_count);
cpus_read_unlock();
}
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 ppc_md.get_random_seed != NULL;
}
EXPORT_SYMBOL_GPL(kvmppc_hwrng_present);
long kvmppc_rm_h_random(struct kvm_vcpu *vcpu)
{
unsigned long rand;
if (ppc_md.get_random_seed &&
ppc_md.get_random_seed(&rand)) {
kvmppc_set_gpr(vcpu, 4, rand);
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(xics_on_xive()))
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;
/* 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);
}
}
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 = READ_ONCE(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 = READ_ONCE(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);
}
static void kvmppc_end_cede(struct kvm_vcpu *vcpu)
{
vcpu->arch.ceded = 0;
if (vcpu->arch.timer_running) {
hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
vcpu->arch.timer_running = 0;
}
}
void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr)
{
/* Guest must always run with ME enabled, HV disabled. */
msr = (msr | MSR_ME) & ~MSR_HV;
/*
* Check for illegal transactional state bit combination
* and if we find it, force the TS field to a safe state.
*/
if ((msr & MSR_TS_MASK) == MSR_TS_MASK)
msr &= ~MSR_TS_MASK;
__kvmppc_set_msr_hv(vcpu, msr);
kvmppc_end_cede(vcpu);
}
EXPORT_SYMBOL_GPL(kvmppc_set_msr_hv);
static void inject_interrupt(struct kvm_vcpu *vcpu, int vec, u64 srr1_flags)
{
unsigned long msr, pc, new_msr, new_pc;
msr = kvmppc_get_msr(vcpu);
pc = kvmppc_get_pc(vcpu);
new_msr = vcpu->arch.intr_msr;
new_pc = vec;
/* If transactional, change to suspend mode on IRQ delivery */
if (MSR_TM_TRANSACTIONAL(msr))
new_msr |= MSR_TS_S;
else
new_msr |= msr & MSR_TS_MASK;
/*
* Perform MSR and PC adjustment for LPCR[AIL]=3 if it is set and
* applicable. AIL=2 is not supported.
*
* AIL does not apply to SRESET, MCE, or HMI (which is never
* delivered to the guest), and does not apply if IR=0 or DR=0.
*/
if (vec != BOOK3S_INTERRUPT_SYSTEM_RESET &&
vec != BOOK3S_INTERRUPT_MACHINE_CHECK &&
(vcpu->arch.vcore->lpcr & LPCR_AIL) == LPCR_AIL_3 &&
(msr & (MSR_IR|MSR_DR)) == (MSR_IR|MSR_DR) ) {
new_msr |= MSR_IR | MSR_DR;
new_pc += 0xC000000000004000ULL;
}
kvmppc_set_srr0(vcpu, pc);
kvmppc_set_srr1(vcpu, (msr & SRR1_MSR_BITS) | srr1_flags);
kvmppc_set_pc(vcpu, new_pc);
__kvmppc_set_msr_hv(vcpu, new_msr);
}
void kvmppc_inject_interrupt_hv(struct kvm_vcpu *vcpu, int vec, u64 srr1_flags)
{
inject_interrupt(vcpu, vec, srr1_flags);
kvmppc_end_cede(vcpu);
}
EXPORT_SYMBOL_GPL(kvmppc_inject_interrupt_hv);
/*
* Is there a PRIV_DOORBELL pending for the guest (on POWER9)?
* Can we inject a Decrementer or a External interrupt?
*/
void kvmppc_guest_entry_inject_int(struct kvm_vcpu *vcpu)
{
int ext;
unsigned long lpcr;
WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300));
/* Insert EXTERNAL bit into LPCR at the MER bit position */
ext = (vcpu->arch.pending_exceptions >> BOOK3S_IRQPRIO_EXTERNAL) & 1;
lpcr = mfspr(SPRN_LPCR);
lpcr |= ext << LPCR_MER_SH;
mtspr(SPRN_LPCR, lpcr);
isync();
if (vcpu->arch.shregs.msr & MSR_EE) {
if (ext) {
inject_interrupt(vcpu, BOOK3S_INTERRUPT_EXTERNAL, 0);
} else {
long int dec = mfspr(SPRN_DEC);
if (!(lpcr & LPCR_LD))
dec = (int) dec;
if (dec < 0)
inject_interrupt(vcpu,
BOOK3S_INTERRUPT_DECREMENTER, 0);
}
}
if (vcpu->arch.doorbell_request) {
mtspr(SPRN_DPDES, 1);
vcpu->arch.vcore->dpdes = 1;
smp_wmb();
vcpu->arch.doorbell_request = 0;
}
}
static void flush_guest_tlb(struct kvm *kvm)
{
unsigned long rb, set;
rb = PPC_BIT(52); /* IS = 2 */
for (set = 0; set < kvm->arch.tlb_sets; ++set) {
/* R=0 PRS=0 RIC=0 */
asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
: : "r" (rb), "i" (0), "i" (0), "i" (0),
"r" (0) : "memory");
rb += PPC_BIT(51); /* increment set number */
}
asm volatile("ptesync": : :"memory");
}
void kvmppc_check_need_tlb_flush(struct kvm *kvm, int pcpu)
{
if (cpumask_test_cpu(pcpu, &kvm->arch.need_tlb_flush)) {
flush_guest_tlb(kvm);
/* Clear the bit after the TLB flush */
cpumask_clear_cpu(pcpu, &kvm->arch.need_tlb_flush);
}
}
EXPORT_SYMBOL_GPL(kvmppc_check_need_tlb_flush);
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