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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/kvm/book3s_hv_builtin.c
parentInitial commit. (diff)
downloadlinux-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.c624
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);