[v3,01/10] RISC-V: KVM: Implement guest external interrupt line management

Message ID	20230615073353.85435-2-apatel@ventanamicro.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@vger.kernel.org> From: Anup Patel <apatel@ventanamicro.com> To: Paolo Bonzini <pbonzini@redhat.com>, Atish Patra <atishp@atishpatra.org> Cc: Palmer Dabbelt <palmer@dabbelt.com>, Paul Walmsley <paul.walmsley@sifive.com>, Andrew Jones <ajones@ventanamicro.com>, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Anup Patel <apatel@ventanamicro.com>, Atish Patra <atishp@rivosinc.com> Subject: [PATCH v3 01/10] RISC-V: KVM: Implement guest external interrupt line management Date: Thu, 15 Jun 2023 13:03:44 +0530 Message-Id: <20230615073353.85435-2-apatel@ventanamicro.com> In-Reply-To: <20230615073353.85435-1-apatel@ventanamicro.com> References: <20230615073353.85435-1-apatel@ventanamicro.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	RISC-V KVM in-kernel AIA irqchip \| expand [v3,00/10] RISC-V KVM in-kernel AIA irqchip [v3,01/10] RISC-V: KVM: Implement guest external interrupt line management [v3,02/10] RISC-V: KVM: Add IMSIC related defines [v3,03/10] RISC-V: KVM: Add APLIC related defines [v3,04/10] RISC-V: KVM: Set kvm_riscv_aia_nr_hgei to zero [v3,05/10] RISC-V: KVM: Skeletal in-kernel AIA irqchip support [v3,06/10] RISC-V: KVM: Implement device interface for AIA irqchip [v3,07/10] RISC-V: KVM: Add in-kernel emulation of AIA APLIC [v3,08/10] RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip [v3,09/10] RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC [v3,10/10] RISC-V: KVM: Expose IMSIC registers as attributes of AIA irqchip

diff --git a/arch/riscv/include/asm/kvm_aia.h b/arch/riscv/include/asm/kvm_aia.h index 1de0717112e5..0938e0cadf80 100644 --- a/arch/riscv/include/asm/kvm_aia.h +++ b/arch/riscv/include/asm/kvm_aia.h @@ -44,10 +44,15 @@ struct kvm_vcpu_aia { #define irqchip_in_kernel(k) ((k)->arch.aia.in_kernel) +extern unsigned int kvm_riscv_aia_nr_hgei; DECLARE_STATIC_KEY_FALSE(kvm_riscv_aia_available); #define kvm_riscv_aia_available() \ static_branch_unlikely(&kvm_riscv_aia_available) +static inline void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu) +{ +} + #define KVM_RISCV_AIA_IMSIC_TOPEI (ISELECT_MASK + 1) static inline int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu, unsigned long isel, @@ -119,6 +124,11 @@ static inline void kvm_riscv_aia_destroy_vm(struct kvm *kvm) { } +int kvm_riscv_aia_alloc_hgei(int cpu, struct kvm_vcpu *owner, + void __iomem **hgei_va, phys_addr_t *hgei_pa); +void kvm_riscv_aia_free_hgei(int cpu, int hgei); +void kvm_riscv_aia_wakeon_hgei(struct kvm_vcpu *owner, bool enable); + void kvm_riscv_aia_enable(void); void kvm_riscv_aia_disable(void); int kvm_riscv_aia_init(void); diff --git a/arch/riscv/kvm/aia.c b/arch/riscv/kvm/aia.c index 4f1286fc7f17..1cee75a8c883 100644 --- a/arch/riscv/kvm/aia.c +++ b/arch/riscv/kvm/aia.c @@ -8,11 +8,47 @@ */ #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> +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; 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; @@ -56,6 +92,7 @@ void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu) bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu, u64 mask) { + int hgei; unsigned long seip; if (!kvm_riscv_aia_available()) @@ -74,6 +111,10 @@ bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu, u64 mask) 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; } @@ -348,6 +389,143 @@ int kvm_riscv_vcpu_aia_rmw_ireg(struct kvm_vcpu *vcpu, unsigned int csr_num, 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 in-kernel irqchip 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()) @@ -362,21 +540,82 @@ void kvm_riscv_aia_enable(void) 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--; + + /* Initialize guest external interrupt line management */ + rc = aia_hgei_init(); + if (rc) + return rc; + /* Enable KVM AIA support */ static_branch_enable(&kvm_riscv_aia_available); @@ -385,4 +624,9 @@ int kvm_riscv_aia_init(void) void kvm_riscv_aia_exit(void) { + if (!kvm_riscv_aia_available()) + return; + + /* Cleanup the HGEI state */ + aia_hgei_exit(); } diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c index a7112d583637..48ae0d4b3932 100644 --- a/arch/riscv/kvm/main.c +++ b/arch/riscv/kvm/main.c @@ -116,7 +116,8 @@ static int __init riscv_kvm_init(void) kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits()); if (kvm_riscv_aia_available()) - kvm_info("AIA available\n"); + kvm_info("AIA available with %d guest external interrupts\n", + kvm_riscv_aia_nr_hgei); rc = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE); if (rc) { diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 8bd9f2a8a0b9..2db62c6c0d3e 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -250,10 +250,12 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) { + kvm_riscv_aia_wakeon_hgei(vcpu, true); } void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) { + kvm_riscv_aia_wakeon_hgei(vcpu, false); } int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)

[v3,01/10] RISC-V: KVM: Implement guest external interrupt line management

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