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-rw-r--r--arch/riscv/kvm/aia.c658
1 files changed, 658 insertions, 0 deletions
diff --git a/arch/riscv/kvm/aia.c b/arch/riscv/kvm/aia.c
new file mode 100644
index 0000000000..74bb274405
--- /dev/null
+++ b/arch/riscv/kvm/aia.c
@@ -0,0 +1,658 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ *
+ * Authors:
+ * Anup Patel <apatel@ventanamicro.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kvm_host.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+#include <asm/hwcap.h>
+#include <asm/kvm_aia_imsic.h>
+
+struct aia_hgei_control {
+ raw_spinlock_t lock;
+ unsigned long free_bitmap;
+ struct kvm_vcpu *owners[BITS_PER_LONG];
+};
+static DEFINE_PER_CPU(struct aia_hgei_control, aia_hgei);
+static int hgei_parent_irq;
+
+unsigned int kvm_riscv_aia_nr_hgei;
+unsigned int kvm_riscv_aia_max_ids;
+DEFINE_STATIC_KEY_FALSE(kvm_riscv_aia_available);
+
+static int aia_find_hgei(struct kvm_vcpu *owner)
+{
+ int i, hgei;
+ unsigned long flags;
+ struct aia_hgei_control *hgctrl = get_cpu_ptr(&aia_hgei);
+
+ raw_spin_lock_irqsave(&hgctrl->lock, flags);
+
+ hgei = -1;
+ for (i = 1; i <= kvm_riscv_aia_nr_hgei; i++) {
+ if (hgctrl->owners[i] == owner) {
+ hgei = i;
+ break;
+ }
+ }
+
+ raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
+
+ put_cpu_ptr(&aia_hgei);
+ return hgei;
+}
+
+static void aia_set_hvictl(bool ext_irq_pending)
+{
+ unsigned long hvictl;
+
+ /*
+ * HVICTL.IID == 9 and HVICTL.IPRIO == 0 represents
+ * no interrupt in HVICTL.
+ */
+
+ hvictl = (IRQ_S_EXT << HVICTL_IID_SHIFT) & HVICTL_IID;
+ hvictl |= ext_irq_pending;
+ csr_write(CSR_HVICTL, hvictl);
+}
+
+#ifdef CONFIG_32BIT
+void kvm_riscv_vcpu_aia_flush_interrupts(struct kvm_vcpu *vcpu)
+{
+ struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
+ unsigned long mask, val;
+
+ if (!kvm_riscv_aia_available())
+ return;
+
+ if (READ_ONCE(vcpu->arch.irqs_pending_mask[1])) {
+ mask = xchg_acquire(&vcpu->arch.irqs_pending_mask[1], 0);
+ val = READ_ONCE(vcpu->arch.irqs_pending[1]) & mask;
+
+ csr->hviph &= ~mask;
+ csr->hviph |= val;
+ }
+}
+
+void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu)
+{
+ struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
+
+ if (kvm_riscv_aia_available())
+ csr->vsieh = csr_read(CSR_VSIEH);
+}
+#endif
+
+bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu, u64 mask)
+{
+ int hgei;
+ unsigned long seip;
+
+ if (!kvm_riscv_aia_available())
+ return false;
+
+#ifdef CONFIG_32BIT
+ if (READ_ONCE(vcpu->arch.irqs_pending[1]) &
+ (vcpu->arch.aia_context.guest_csr.vsieh & upper_32_bits(mask)))
+ return true;
+#endif
+
+ seip = vcpu->arch.guest_csr.vsie;
+ seip &= (unsigned long)mask;
+ seip &= BIT(IRQ_S_EXT);
+
+ if (!kvm_riscv_aia_initialized(vcpu->kvm) || !seip)
+ return false;
+
+ hgei = aia_find_hgei(vcpu);
+ if (hgei > 0)
+ return !!(csr_read(CSR_HGEIP) & BIT(hgei));
+
+ return false;
+}
+
+void kvm_riscv_vcpu_aia_update_hvip(struct kvm_vcpu *vcpu)
+{
+ struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
+
+ if (!kvm_riscv_aia_available())
+ return;
+
+#ifdef CONFIG_32BIT
+ csr_write(CSR_HVIPH, vcpu->arch.aia_context.guest_csr.hviph);
+#endif
+ aia_set_hvictl(!!(csr->hvip & BIT(IRQ_VS_EXT)));
+}
+
+void kvm_riscv_vcpu_aia_load(struct kvm_vcpu *vcpu, int cpu)
+{
+ struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
+
+ if (!kvm_riscv_aia_available())
+ return;
+
+ csr_write(CSR_VSISELECT, csr->vsiselect);
+ csr_write(CSR_HVIPRIO1, csr->hviprio1);
+ csr_write(CSR_HVIPRIO2, csr->hviprio2);
+#ifdef CONFIG_32BIT
+ csr_write(CSR_VSIEH, csr->vsieh);
+ csr_write(CSR_HVIPH, csr->hviph);
+ csr_write(CSR_HVIPRIO1H, csr->hviprio1h);
+ csr_write(CSR_HVIPRIO2H, csr->hviprio2h);
+#endif
+}
+
+void kvm_riscv_vcpu_aia_put(struct kvm_vcpu *vcpu)
+{
+ struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
+
+ if (!kvm_riscv_aia_available())
+ return;
+
+ csr->vsiselect = csr_read(CSR_VSISELECT);
+ csr->hviprio1 = csr_read(CSR_HVIPRIO1);
+ csr->hviprio2 = csr_read(CSR_HVIPRIO2);
+#ifdef CONFIG_32BIT
+ csr->vsieh = csr_read(CSR_VSIEH);
+ csr->hviph = csr_read(CSR_HVIPH);
+ csr->hviprio1h = csr_read(CSR_HVIPRIO1H);
+ csr->hviprio2h = csr_read(CSR_HVIPRIO2H);
+#endif
+}
+
+int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu,
+ unsigned long reg_num,
+ unsigned long *out_val)
+{
+ struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
+
+ if (reg_num >= sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long))
+ return -ENOENT;
+
+ *out_val = 0;
+ if (kvm_riscv_aia_available())
+ *out_val = ((unsigned long *)csr)[reg_num];
+
+ return 0;
+}
+
+int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu,
+ unsigned long reg_num,
+ unsigned long val)
+{
+ struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
+
+ if (reg_num >= sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long))
+ return -ENOENT;
+
+ if (kvm_riscv_aia_available()) {
+ ((unsigned long *)csr)[reg_num] = val;
+
+#ifdef CONFIG_32BIT
+ if (reg_num == KVM_REG_RISCV_CSR_AIA_REG(siph))
+ WRITE_ONCE(vcpu->arch.irqs_pending_mask[1], 0);
+#endif
+ }
+
+ return 0;
+}
+
+int kvm_riscv_vcpu_aia_rmw_topei(struct kvm_vcpu *vcpu,
+ unsigned int csr_num,
+ unsigned long *val,
+ unsigned long new_val,
+ unsigned long wr_mask)
+{
+ /* If AIA not available then redirect trap */
+ if (!kvm_riscv_aia_available())
+ return KVM_INSN_ILLEGAL_TRAP;
+
+ /* If AIA not initialized then forward to user space */
+ if (!kvm_riscv_aia_initialized(vcpu->kvm))
+ return KVM_INSN_EXIT_TO_USER_SPACE;
+
+ return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, KVM_RISCV_AIA_IMSIC_TOPEI,
+ val, new_val, wr_mask);
+}
+
+/*
+ * External IRQ priority always read-only zero. This means default
+ * priority order is always preferred for external IRQs unless
+ * HVICTL.IID == 9 and HVICTL.IPRIO != 0
+ */
+static int aia_irq2bitpos[] = {
+0, 8, -1, -1, 16, 24, -1, -1, /* 0 - 7 */
+32, -1, -1, -1, -1, 40, 48, 56, /* 8 - 15 */
+64, 72, 80, 88, 96, 104, 112, 120, /* 16 - 23 */
+-1, -1, -1, -1, -1, -1, -1, -1, /* 24 - 31 */
+-1, -1, -1, -1, -1, -1, -1, -1, /* 32 - 39 */
+-1, -1, -1, -1, -1, -1, -1, -1, /* 40 - 47 */
+-1, -1, -1, -1, -1, -1, -1, -1, /* 48 - 55 */
+-1, -1, -1, -1, -1, -1, -1, -1, /* 56 - 63 */
+};
+
+static u8 aia_get_iprio8(struct kvm_vcpu *vcpu, unsigned int irq)
+{
+ unsigned long hviprio;
+ int bitpos = aia_irq2bitpos[irq];
+
+ if (bitpos < 0)
+ return 0;
+
+ switch (bitpos / BITS_PER_LONG) {
+ case 0:
+ hviprio = csr_read(CSR_HVIPRIO1);
+ break;
+ case 1:
+#ifndef CONFIG_32BIT
+ hviprio = csr_read(CSR_HVIPRIO2);
+ break;
+#else
+ hviprio = csr_read(CSR_HVIPRIO1H);
+ break;
+ case 2:
+ hviprio = csr_read(CSR_HVIPRIO2);
+ break;
+ case 3:
+ hviprio = csr_read(CSR_HVIPRIO2H);
+ break;
+#endif
+ default:
+ return 0;
+ }
+
+ return (hviprio >> (bitpos % BITS_PER_LONG)) & TOPI_IPRIO_MASK;
+}
+
+static void aia_set_iprio8(struct kvm_vcpu *vcpu, unsigned int irq, u8 prio)
+{
+ unsigned long hviprio;
+ int bitpos = aia_irq2bitpos[irq];
+
+ if (bitpos < 0)
+ return;
+
+ switch (bitpos / BITS_PER_LONG) {
+ case 0:
+ hviprio = csr_read(CSR_HVIPRIO1);
+ break;
+ case 1:
+#ifndef CONFIG_32BIT
+ hviprio = csr_read(CSR_HVIPRIO2);
+ break;
+#else
+ hviprio = csr_read(CSR_HVIPRIO1H);
+ break;
+ case 2:
+ hviprio = csr_read(CSR_HVIPRIO2);
+ break;
+ case 3:
+ hviprio = csr_read(CSR_HVIPRIO2H);
+ break;
+#endif
+ default:
+ return;
+ }
+
+ hviprio &= ~(TOPI_IPRIO_MASK << (bitpos % BITS_PER_LONG));
+ hviprio |= (unsigned long)prio << (bitpos % BITS_PER_LONG);
+
+ switch (bitpos / BITS_PER_LONG) {
+ case 0:
+ csr_write(CSR_HVIPRIO1, hviprio);
+ break;
+ case 1:
+#ifndef CONFIG_32BIT
+ csr_write(CSR_HVIPRIO2, hviprio);
+ break;
+#else
+ csr_write(CSR_HVIPRIO1H, hviprio);
+ break;
+ case 2:
+ csr_write(CSR_HVIPRIO2, hviprio);
+ break;
+ case 3:
+ csr_write(CSR_HVIPRIO2H, hviprio);
+ break;
+#endif
+ default:
+ return;
+ }
+}
+
+static int aia_rmw_iprio(struct kvm_vcpu *vcpu, unsigned int isel,
+ unsigned long *val, unsigned long new_val,
+ unsigned long wr_mask)
+{
+ int i, first_irq, nirqs;
+ unsigned long old_val;
+ u8 prio;
+
+#ifndef CONFIG_32BIT
+ if (isel & 0x1)
+ return KVM_INSN_ILLEGAL_TRAP;
+#endif
+
+ nirqs = 4 * (BITS_PER_LONG / 32);
+ first_irq = (isel - ISELECT_IPRIO0) * 4;
+
+ old_val = 0;
+ for (i = 0; i < nirqs; i++) {
+ prio = aia_get_iprio8(vcpu, first_irq + i);
+ old_val |= (unsigned long)prio << (TOPI_IPRIO_BITS * i);
+ }
+
+ if (val)
+ *val = old_val;
+
+ if (wr_mask) {
+ new_val = (old_val & ~wr_mask) | (new_val & wr_mask);
+ for (i = 0; i < nirqs; i++) {
+ prio = (new_val >> (TOPI_IPRIO_BITS * i)) &
+ TOPI_IPRIO_MASK;
+ aia_set_iprio8(vcpu, first_irq + i, prio);
+ }
+ }
+
+ return KVM_INSN_CONTINUE_NEXT_SEPC;
+}
+
+int kvm_riscv_vcpu_aia_rmw_ireg(struct kvm_vcpu *vcpu, unsigned int csr_num,
+ unsigned long *val, unsigned long new_val,
+ unsigned long wr_mask)
+{
+ unsigned int isel;
+
+ /* If AIA not available then redirect trap */
+ if (!kvm_riscv_aia_available())
+ return KVM_INSN_ILLEGAL_TRAP;
+
+ /* First try to emulate in kernel space */
+ isel = csr_read(CSR_VSISELECT) & ISELECT_MASK;
+ if (isel >= ISELECT_IPRIO0 && isel <= ISELECT_IPRIO15)
+ return aia_rmw_iprio(vcpu, isel, val, new_val, wr_mask);
+ else if (isel >= IMSIC_FIRST && isel <= IMSIC_LAST &&
+ kvm_riscv_aia_initialized(vcpu->kvm))
+ return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, isel, val, new_val,
+ wr_mask);
+
+ /* We can't handle it here so redirect to user space */
+ return KVM_INSN_EXIT_TO_USER_SPACE;
+}
+
+int kvm_riscv_aia_alloc_hgei(int cpu, struct kvm_vcpu *owner,
+ void __iomem **hgei_va, phys_addr_t *hgei_pa)
+{
+ int ret = -ENOENT;
+ unsigned long flags;
+ struct aia_hgei_control *hgctrl = per_cpu_ptr(&aia_hgei, cpu);
+
+ if (!kvm_riscv_aia_available() || !hgctrl)
+ return -ENODEV;
+
+ raw_spin_lock_irqsave(&hgctrl->lock, flags);
+
+ if (hgctrl->free_bitmap) {
+ ret = __ffs(hgctrl->free_bitmap);
+ hgctrl->free_bitmap &= ~BIT(ret);
+ hgctrl->owners[ret] = owner;
+ }
+
+ raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
+
+ /* TODO: To be updated later by AIA IMSIC HW guest file support */
+ if (hgei_va)
+ *hgei_va = NULL;
+ if (hgei_pa)
+ *hgei_pa = 0;
+
+ return ret;
+}
+
+void kvm_riscv_aia_free_hgei(int cpu, int hgei)
+{
+ unsigned long flags;
+ struct aia_hgei_control *hgctrl = per_cpu_ptr(&aia_hgei, cpu);
+
+ if (!kvm_riscv_aia_available() || !hgctrl)
+ return;
+
+ raw_spin_lock_irqsave(&hgctrl->lock, flags);
+
+ if (hgei > 0 && hgei <= kvm_riscv_aia_nr_hgei) {
+ if (!(hgctrl->free_bitmap & BIT(hgei))) {
+ hgctrl->free_bitmap |= BIT(hgei);
+ hgctrl->owners[hgei] = NULL;
+ }
+ }
+
+ raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
+}
+
+void kvm_riscv_aia_wakeon_hgei(struct kvm_vcpu *owner, bool enable)
+{
+ int hgei;
+
+ if (!kvm_riscv_aia_available())
+ return;
+
+ hgei = aia_find_hgei(owner);
+ if (hgei > 0) {
+ if (enable)
+ csr_set(CSR_HGEIE, BIT(hgei));
+ else
+ csr_clear(CSR_HGEIE, BIT(hgei));
+ }
+}
+
+static irqreturn_t hgei_interrupt(int irq, void *dev_id)
+{
+ int i;
+ unsigned long hgei_mask, flags;
+ struct aia_hgei_control *hgctrl = get_cpu_ptr(&aia_hgei);
+
+ hgei_mask = csr_read(CSR_HGEIP) & csr_read(CSR_HGEIE);
+ csr_clear(CSR_HGEIE, hgei_mask);
+
+ raw_spin_lock_irqsave(&hgctrl->lock, flags);
+
+ for_each_set_bit(i, &hgei_mask, BITS_PER_LONG) {
+ if (hgctrl->owners[i])
+ kvm_vcpu_kick(hgctrl->owners[i]);
+ }
+
+ raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
+
+ put_cpu_ptr(&aia_hgei);
+ return IRQ_HANDLED;
+}
+
+static int aia_hgei_init(void)
+{
+ int cpu, rc;
+ struct irq_domain *domain;
+ struct aia_hgei_control *hgctrl;
+
+ /* Initialize per-CPU guest external interrupt line management */
+ for_each_possible_cpu(cpu) {
+ hgctrl = per_cpu_ptr(&aia_hgei, cpu);
+ raw_spin_lock_init(&hgctrl->lock);
+ if (kvm_riscv_aia_nr_hgei) {
+ hgctrl->free_bitmap =
+ BIT(kvm_riscv_aia_nr_hgei + 1) - 1;
+ hgctrl->free_bitmap &= ~BIT(0);
+ } else
+ hgctrl->free_bitmap = 0;
+ }
+
+ /* Find INTC irq domain */
+ domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
+ DOMAIN_BUS_ANY);
+ if (!domain) {
+ kvm_err("unable to find INTC domain\n");
+ return -ENOENT;
+ }
+
+ /* Map per-CPU SGEI interrupt from INTC domain */
+ hgei_parent_irq = irq_create_mapping(domain, IRQ_S_GEXT);
+ if (!hgei_parent_irq) {
+ kvm_err("unable to map SGEI IRQ\n");
+ return -ENOMEM;
+ }
+
+ /* Request per-CPU SGEI interrupt */
+ rc = request_percpu_irq(hgei_parent_irq, hgei_interrupt,
+ "riscv-kvm", &aia_hgei);
+ if (rc) {
+ kvm_err("failed to request SGEI IRQ\n");
+ return rc;
+ }
+
+ return 0;
+}
+
+static void aia_hgei_exit(void)
+{
+ /* Free per-CPU SGEI interrupt */
+ free_percpu_irq(hgei_parent_irq, &aia_hgei);
+}
+
+void kvm_riscv_aia_enable(void)
+{
+ if (!kvm_riscv_aia_available())
+ return;
+
+ aia_set_hvictl(false);
+ csr_write(CSR_HVIPRIO1, 0x0);
+ csr_write(CSR_HVIPRIO2, 0x0);
+#ifdef CONFIG_32BIT
+ csr_write(CSR_HVIPH, 0x0);
+ csr_write(CSR_HIDELEGH, 0x0);
+ csr_write(CSR_HVIPRIO1H, 0x0);
+ csr_write(CSR_HVIPRIO2H, 0x0);
+#endif
+
+ /* Enable per-CPU SGEI interrupt */
+ enable_percpu_irq(hgei_parent_irq,
+ irq_get_trigger_type(hgei_parent_irq));
+ csr_set(CSR_HIE, BIT(IRQ_S_GEXT));
+}
+
+void kvm_riscv_aia_disable(void)
+{
+ int i;
+ unsigned long flags;
+ struct kvm_vcpu *vcpu;
+ struct aia_hgei_control *hgctrl;
+
+ if (!kvm_riscv_aia_available())
+ return;
+ hgctrl = get_cpu_ptr(&aia_hgei);
+
+ /* Disable per-CPU SGEI interrupt */
+ csr_clear(CSR_HIE, BIT(IRQ_S_GEXT));
+ disable_percpu_irq(hgei_parent_irq);
+
+ aia_set_hvictl(false);
+
+ raw_spin_lock_irqsave(&hgctrl->lock, flags);
+
+ for (i = 0; i <= kvm_riscv_aia_nr_hgei; i++) {
+ vcpu = hgctrl->owners[i];
+ if (!vcpu)
+ continue;
+
+ /*
+ * We release hgctrl->lock before notifying IMSIC
+ * so that we don't have lock ordering issues.
+ */
+ raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
+
+ /* Notify IMSIC */
+ kvm_riscv_vcpu_aia_imsic_release(vcpu);
+
+ /*
+ * Wakeup VCPU if it was blocked so that it can
+ * run on other HARTs
+ */
+ if (csr_read(CSR_HGEIE) & BIT(i)) {
+ csr_clear(CSR_HGEIE, BIT(i));
+ kvm_vcpu_kick(vcpu);
+ }
+
+ raw_spin_lock_irqsave(&hgctrl->lock, flags);
+ }
+
+ raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
+
+ put_cpu_ptr(&aia_hgei);
+}
+
+int kvm_riscv_aia_init(void)
+{
+ int rc;
+
+ if (!riscv_isa_extension_available(NULL, SxAIA))
+ return -ENODEV;
+
+ /* Figure-out number of bits in HGEIE */
+ csr_write(CSR_HGEIE, -1UL);
+ kvm_riscv_aia_nr_hgei = fls_long(csr_read(CSR_HGEIE));
+ csr_write(CSR_HGEIE, 0);
+ if (kvm_riscv_aia_nr_hgei)
+ kvm_riscv_aia_nr_hgei--;
+
+ /*
+ * Number of usable HGEI lines should be minimum of per-HART
+ * IMSIC guest files and number of bits in HGEIE
+ *
+ * TODO: To be updated later by AIA IMSIC HW guest file support
+ */
+ kvm_riscv_aia_nr_hgei = 0;
+
+ /*
+ * Find number of guest MSI IDs
+ *
+ * TODO: To be updated later by AIA IMSIC HW guest file support
+ */
+ kvm_riscv_aia_max_ids = IMSIC_MAX_ID;
+
+ /* Initialize guest external interrupt line management */
+ rc = aia_hgei_init();
+ if (rc)
+ return rc;
+
+ /* Register device operations */
+ rc = kvm_register_device_ops(&kvm_riscv_aia_device_ops,
+ KVM_DEV_TYPE_RISCV_AIA);
+ if (rc) {
+ aia_hgei_exit();
+ return rc;
+ }
+
+ /* Enable KVM AIA support */
+ static_branch_enable(&kvm_riscv_aia_available);
+
+ return 0;
+}
+
+void kvm_riscv_aia_exit(void)
+{
+ if (!kvm_riscv_aia_available())
+ return;
+
+ /* Unregister device operations */
+ kvm_unregister_device_ops(KVM_DEV_TYPE_RISCV_AIA);
+
+ /* Cleanup the HGEI state */
+ aia_hgei_exit();
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 19:50:10 +0000