The RISC-V host will have one guest external interrupt line for each
VS-level IMSICs associated with a HART. The guest external interrupt
lines are per-HART resources and hypervisor can use HGEIE, HGEIP, and
HIE CSRs to manage these guest external interrupt lines.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
arch/riscv/include/asm/kvm_aia.h | 10 ++
arch/riscv/kvm/aia.c | 241 +++++++++++++++++++++++++++++++
arch/riscv/kvm/main.c | 3 +-
arch/riscv/kvm/vcpu.c | 2 +
4 files changed, 255 insertions(+), 1 deletion(-)
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 3d68189e0bb1..f375069fdaf4 100644
--- a/arch/riscv/kvm/aia.c
+++ b/arch/riscv/kvm/aia.c
@@ -7,11 +7,46 @@
* Anup Patel <apatel@ventanamicro.com>
*/
+#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 = this_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);
+
+ return hgei;
+}
+
static void aia_set_hvictl(bool ext_irq_pending)
{
unsigned long hvictl;
@@ -55,6 +90,7 @@ 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())
@@ -72,6 +108,10 @@ 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)) ? true : false;
+
return false;
}
@@ -343,6 +383,144 @@ 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())
+ return -ENODEV;
+ if (!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 = this_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);
+
+ 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())
@@ -357,21 +535,79 @@ 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 = this_cpu_ptr(&aia_hgei);
+
if (!kvm_riscv_aia_available())
return;
+ /* 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);
}
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);
@@ -380,4 +616,9 @@ 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 d8ff44eb04ca..5cf37dbe8a38 100644
--- a/arch/riscv/kvm/main.c
+++ b/arch/riscv/kvm/main.c
@@ -125,7 +125,8 @@ int kvm_arch_init(void *opaque)
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);
return 0;
}
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 151b35b3b05f..1daa1936b642 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -240,10 +240,12 @@ 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)
--
2.34.1On Fri, Jan 27, 2023 at 11:28 PM Anup Patel <apatel@ventanamicro.com> wrote:
>
> The RISC-V host will have one guest external interrupt line for each
> VS-level IMSICs associated with a HART. The guest external interrupt
> lines are per-HART resources and hypervisor can use HGEIE, HGEIP, and
> HIE CSRs to manage these guest external interrupt lines.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
> arch/riscv/include/asm/kvm_aia.h | 10 ++
> arch/riscv/kvm/aia.c | 241 +++++++++++++++++++++++++++++++
> arch/riscv/kvm/main.c | 3 +-
> arch/riscv/kvm/vcpu.c | 2 +
> 4 files changed, 255 insertions(+), 1 deletion(-)
>
> 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 3d68189e0bb1..f375069fdaf4 100644
> --- a/arch/riscv/kvm/aia.c
> +++ b/arch/riscv/kvm/aia.c
> @@ -7,11 +7,46 @@
> * Anup Patel <apatel@ventanamicro.com>
> */
>
> +#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 = this_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);
> +
> + return hgei;
> +}
> +
> static void aia_set_hvictl(bool ext_irq_pending)
> {
> unsigned long hvictl;
> @@ -55,6 +90,7 @@ 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())
> @@ -72,6 +108,10 @@ 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)) ? true : false;
> +
> return false;
> }
>
> @@ -343,6 +383,144 @@ 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())
> + return -ENODEV;
> + if (!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 = this_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);
> +
> + 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())
> @@ -357,21 +535,79 @@ 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 = this_cpu_ptr(&aia_hgei);
> +
> if (!kvm_riscv_aia_available())
> return;
>
> + /* 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);
> + }
> +
We shouldn't access vcpu related data here as
kvm_arch_destroy_vm/kvm_destroy_vcpus
is called before hardware_disable_all is invoked.
> + raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
> }
>
> 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);
>
> @@ -380,4 +616,9 @@ 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 d8ff44eb04ca..5cf37dbe8a38 100644
> --- a/arch/riscv/kvm/main.c
> +++ b/arch/riscv/kvm/main.c
> @@ -125,7 +125,8 @@ int kvm_arch_init(void *opaque)
> 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);
>
> return 0;
> }
> diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
> index 151b35b3b05f..1daa1936b642 100644
> --- a/arch/riscv/kvm/vcpu.c
> +++ b/arch/riscv/kvm/vcpu.c
> @@ -240,10 +240,12 @@ 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)
> --
> 2.34.1
>
--
Regards,
Atish
On Wed, Feb 8, 2023 at 5:45 AM Atish Patra <atishp@atishpatra.org> wrote:
>
> On Fri, Jan 27, 2023 at 11:28 PM Anup Patel <apatel@ventanamicro.com> wrote:
> >
> > The RISC-V host will have one guest external interrupt line for each
> > VS-level IMSICs associated with a HART. The guest external interrupt
> > lines are per-HART resources and hypervisor can use HGEIE, HGEIP, and
> > HIE CSRs to manage these guest external interrupt lines.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> > arch/riscv/include/asm/kvm_aia.h | 10 ++
> > arch/riscv/kvm/aia.c | 241 +++++++++++++++++++++++++++++++
> > arch/riscv/kvm/main.c | 3 +-
> > arch/riscv/kvm/vcpu.c | 2 +
> > 4 files changed, 255 insertions(+), 1 deletion(-)
> >
> > 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 3d68189e0bb1..f375069fdaf4 100644
> > --- a/arch/riscv/kvm/aia.c
> > +++ b/arch/riscv/kvm/aia.c
> > @@ -7,11 +7,46 @@
> > * Anup Patel <apatel@ventanamicro.com>
> > */
> >
> > +#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 = this_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);
> > +
> > + return hgei;
> > +}
> > +
> > static void aia_set_hvictl(bool ext_irq_pending)
> > {
> > unsigned long hvictl;
> > @@ -55,6 +90,7 @@ 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())
> > @@ -72,6 +108,10 @@ 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)) ? true : false;
> > +
> > return false;
> > }
> >
> > @@ -343,6 +383,144 @@ 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())
> > + return -ENODEV;
> > + if (!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 = this_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);
> > +
> > + 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())
> > @@ -357,21 +535,79 @@ 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 = this_cpu_ptr(&aia_hgei);
> > +
> > if (!kvm_riscv_aia_available())
> > return;
> >
> > + /* 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);
> > + }
> > +
>
> We shouldn't access vcpu related data here as
> kvm_arch_destroy_vm/kvm_destroy_vcpus
> is called before hardware_disable_all is invoked.
This is for CPU hotplug where the VM/VCPU are not
destroyed but the host CPU is going down so we need
to cleanup sleeping VCPUs.
Regards,
Anup
>
> > + raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
> > }
> >
> > 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);
> >
> > @@ -380,4 +616,9 @@ 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 d8ff44eb04ca..5cf37dbe8a38 100644
> > --- a/arch/riscv/kvm/main.c
> > +++ b/arch/riscv/kvm/main.c
> > @@ -125,7 +125,8 @@ int kvm_arch_init(void *opaque)
> > 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);
> >
> > return 0;
> > }
> > diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
> > index 151b35b3b05f..1daa1936b642 100644
> > --- a/arch/riscv/kvm/vcpu.c
> > +++ b/arch/riscv/kvm/vcpu.c
> > @@ -240,10 +240,12 @@ 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)
> > --
> > 2.34.1
> >
>
>
> --
> Regards,
> Atish
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