diff options
Diffstat (limited to 'kernel/arch/powerpc/kvm/book3s_hv_builtin.c')
-rw-r--r-- | kernel/arch/powerpc/kvm/book3s_hv_builtin.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/kvm/book3s_hv_builtin.c b/kernel/arch/powerpc/kvm/book3s_hv_builtin.c new file mode 100644 index 000000000..ed2589d45 --- /dev/null +++ b/kernel/arch/powerpc/kvm/book3s_hv_builtin.c @@ -0,0 +1,261 @@ +/* + * 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/cputable.h> +#include <asm/kvm_ppc.h> +#include <asm/kvm_book3s.h> +#include <asm/archrandom.h> +#include <asm/xics.h> +#include <asm/dbell.h> +#include <asm/cputhreads.h> + +#define KVM_CMA_CHUNK_ORDER 18 + +/* + * 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(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)); +} +EXPORT_SYMBOL_GPL(kvm_alloc_hpt); + +void kvm_release_hpt(struct page *page, unsigned long nr_pages) +{ + cma_release(kvm_cma, page, nr_pages); +} +EXPORT_SYMBOL_GPL(kvm_release_hpt); + +/** + * 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); + } +} + +/* + * 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 = vcpu->arch.vcore; + 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(vcpu->arch.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(vcpu->arch.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) +{ + if (powernv_get_random_real_mode(&vcpu->arch.gpr[4])) + return H_SUCCESS; + + return H_HARDWARE; +} + +static inline void rm_writeb(unsigned long paddr, u8 val) +{ + __asm__ __volatile__("stbcix %0,0,%1" + : : "r" (val), "r" (paddr) : "memory"); +} + +/* + * Send an interrupt or message to another CPU. + * This can only be called in real mode. + * The caller needs to include any barrier needed to order writes + * to memory vs. the IPI/message. + */ +void kvmhv_rm_send_ipi(int cpu) +{ + unsigned long xics_phys; + + /* 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())) { + unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER); + msg |= cpu_thread_in_core(cpu); + __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg)); + return; + } + + /* Else poke the target with an IPI */ + xics_phys = paca[cpu].kvm_hstate.xics_phys; + rm_writeb(xics_phys + XICS_MFRR, 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; + int me, ee; + + /* 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)); +} |