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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/kvm/book3s_hv_builtin.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_builtin.c')
-rw-r--r-- | arch/powerpc/kvm/book3s_hv_builtin.c | 624 |
1 files changed, 624 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c new file mode 100644 index 000000000..da85f0463 --- /dev/null +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -0,0 +1,624 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> + */ + +#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" + +/* + * 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) +{ + if (ppc_md.get_random_seed && + ppc_md.get_random_seed(&vcpu->arch.regs.gpr[4])) + 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 = 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); +} + +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; + vcpu->arch.shregs.msr = 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); + vcpu->arch.shregs.msr = 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); |