Re: [PATCH v8 2/2] LoongArch: KVM: Add dmsintc inject msi to the dest vcpu
From: Huacai Chen
Date: Thu Mar 26 2026 - 08:47:29 EST
On Thu, Mar 26, 2026 at 8:26 PM gaosong <gaosong@xxxxxxxxxxx> wrote:
>
> 在 2026/3/26 下午3:52, Huacai Chen 写道:
> > Hi, Song,
> >
> > I'm sorry but it seems there are still bugs...
> >
> > On Tue, Mar 24, 2026 at 5:41 PM Song Gao <gaosong@xxxxxxxxxxx> wrote:
> >> Implement irqfd deliver msi to vcpu and vcpu dmsintc inject irq.
> >> Add irqfd choice dmsintc to set msi irq by the msg_addr and
> >> implement dmsintc set msi irq.
> >>
> >> Signed-off-by: Song Gao <gaosong@xxxxxxxxxxx>
> >> ---
> >> arch/loongarch/include/asm/kvm_dmsintc.h | 5 ++
> >> arch/loongarch/include/asm/kvm_pch_pic.h | 4 +-
> >> arch/loongarch/kvm/intc/dmsintc.c | 73 ++++++++++++++++++++++++
> >> arch/loongarch/kvm/intc/pch_pic.c | 16 +++++-
> >> arch/loongarch/kvm/interrupt.c | 2 +
> >> arch/loongarch/kvm/irqfd.c | 11 ++--
> >> 6 files changed, 102 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/arch/loongarch/include/asm/kvm_dmsintc.h b/arch/loongarch/include/asm/kvm_dmsintc.h
> >> index b04b89dd2a35..081ec8a7b874 100644
> >> --- a/arch/loongarch/include/asm/kvm_dmsintc.h
> >> +++ b/arch/loongarch/include/asm/kvm_dmsintc.h
> >> @@ -11,11 +11,16 @@ struct loongarch_dmsintc {
> >> struct kvm *kvm;
> >> uint64_t msg_addr_base;
> >> uint64_t msg_addr_size;
> >> + uint32_t cpu_mask;
> >> };
> >>
> >> struct dmsintc_state {
> >> atomic64_t vector_map[4];
> >> };
> >>
> >> +void dmsintc_inject_irq(struct kvm_vcpu *vcpu);
> >> +int dmsintc_deliver_msi_to_vcpu(struct kvm *kvm, struct kvm_vcpu *vcpu,
> >> + u32 vector, int level);
> >> +int kvm_dmsintc_set_msi_irq(struct kvm *kvm, u32 addr, int data, int level);
> > I think addr should be u64.
> Got it.
> >> int kvm_loongarch_register_dmsintc_device(void);
> >> #endif
> >> diff --git a/arch/loongarch/include/asm/kvm_pch_pic.h b/arch/loongarch/include/asm/kvm_pch_pic.h
> >> index 7f33a3039272..5f49b1f82c56 100644
> >> --- a/arch/loongarch/include/asm/kvm_pch_pic.h
> >> +++ b/arch/loongarch/include/asm/kvm_pch_pic.h
> >> @@ -70,6 +70,8 @@ struct loongarch_pch_pic {
> >>
> >> int kvm_loongarch_register_pch_pic_device(void);
> >> void pch_pic_set_irq(struct loongarch_pch_pic *s, int irq, int level);
> >> -void pch_msi_set_irq(struct kvm *kvm, int irq, int level);
> >> +struct kvm_kernel_irq_routing_entry;
> >> +int pch_msi_set_irq(struct kvm *kvm,
> >> + struct kvm_kernel_irq_routing_entry *e, int level);
> >>
> >> #endif /* __ASM_KVM_PCH_PIC_H */
> >> diff --git a/arch/loongarch/kvm/intc/dmsintc.c b/arch/loongarch/kvm/intc/dmsintc.c
> >> index 1bb61e55d061..6837ccbb4473 100644
> >> --- a/arch/loongarch/kvm/intc/dmsintc.c
> >> +++ b/arch/loongarch/kvm/intc/dmsintc.c
> >> @@ -4,9 +4,82 @@
> >> */
> >>
> >> #include <linux/kvm_host.h>
> >> +#include <asm/kvm_csr.h>
> >> #include <asm/kvm_dmsintc.h>
> >> #include <asm/kvm_vcpu.h>
> >>
> >> +int dmsintc_deliver_msi_to_vcpu(struct kvm *kvm,
> >> + struct kvm_vcpu *vcpu,
> >> + u32 vector, int level)
> >> +{
> >> + struct kvm_interrupt vcpu_irq;
> >> + struct dmsintc_state *ds;
> >> +
> >> + if (!level)
> >> + return 0;
> >> + if (!vcpu || vector >= 256)
> >> + return -EINVAL;
> >> + ds = &vcpu->arch.dmsintc_state;
> >> + if (!ds)
> >> + return -ENODEV;
> >> + set_bit(vector, (unsigned long *)&ds->vector_map);
> >> + vcpu_irq.irq = INT_AVEC;
> >> + kvm_vcpu_ioctl_interrupt(vcpu, &vcpu_irq);
> >> + kvm_vcpu_kick(vcpu);
> >> + return 0;
> >> +}
> >> +
> >> +int kvm_dmsintc_set_msi_irq(struct kvm *kvm, u32 addr, int data, int level)
> > The kvm_ prefix can be removed.
> I will remove it.
> >> +{
> >> + unsigned int virq, dest;
> >> + struct kvm_vcpu *vcpu;
> >> +
> >> + virq = (addr >> AVEC_IRQ_SHIFT) & AVEC_IRQ_MASK;
> >> + dest = (addr >> AVEC_CPU_SHIFT) & kvm->arch.dmsintc->cpu_mask;
> >> + if (dest > KVM_MAX_VCPUS)
> > I think it should be "if (dest > KVM_MAX_VCPUS)".
> hmm.I'm not quite sure about here , or ">=" ?
Yes, I mean it should be ">=".
Huacai
> >> + return -EINVAL;
> >> + vcpu = kvm_get_vcpu_by_cpuid(kvm, dest);
> >> + if (!vcpu)
> >> + return -EINVAL;
> >> + return dmsintc_deliver_msi_to_vcpu(kvm, vcpu, virq, level);
> >> +}
> >> +
> >> +void dmsintc_inject_irq(struct kvm_vcpu *vcpu)
> >> +{
> >> + struct dmsintc_state *ds = &vcpu->arch.dmsintc_state;
> >> + unsigned int i;
> >> + unsigned long temp[4], old;
> >> +
> >> + if (!ds)
> >> + return;
> >> +
> >> + for (i = 0; i < 4; i++) {
> >> + old = atomic64_read(&(ds->vector_map[i]));
> >> + if (old)
> >> + temp[i] = atomic64_xchg(&(ds->vector_map[i]), 0);
> >> + }
> >> +
> >> + if (temp[0]) {
> >> + old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR0);
> >> + kvm_write_hw_gcsr(LOONGARCH_CSR_ISR0, temp[0]|old);
> >> + }
> >> +
> >> + if (temp[1]) {
> >> + old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR1);
> >> + kvm_write_hw_gcsr(LOONGARCH_CSR_ISR1, temp[1]|old);
> >> + }
> >> +
> >> + if (temp[2]) {
> >> + old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR2);
> >> + kvm_write_hw_gcsr(LOONGARCH_CSR_ISR2, temp[2]|old);
> >> + }
> >> +
> >> + if (temp[3]) {
> >> + old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR3);
> >> + kvm_write_hw_gcsr(LOONGARCH_CSR_ISR3, temp[3]|old);
> >> + }
> >> +}
> >> +
> >> static int kvm_dmsintc_ctrl_access(struct kvm_device *dev,
> >> struct kvm_device_attr *attr,
> >> bool is_write)
> >> diff --git a/arch/loongarch/kvm/intc/pch_pic.c b/arch/loongarch/kvm/intc/pch_pic.c
> >> index dd7e7f8d53db..1c0ed0665736 100644
> >> --- a/arch/loongarch/kvm/intc/pch_pic.c
> >> +++ b/arch/loongarch/kvm/intc/pch_pic.c
> >> @@ -4,6 +4,7 @@
> >> */
> >>
> >> #include <asm/kvm_eiointc.h>
> >> +#include <asm/kvm_dmsintc.h>
> >> #include <asm/kvm_pch_pic.h>
> >> #include <asm/kvm_vcpu.h>
> >> #include <linux/count_zeros.h>
> >> @@ -67,9 +68,20 @@ void pch_pic_set_irq(struct loongarch_pch_pic *s, int irq, int level)
> >> }
> >>
> >> /* msi irq handler */
> >> -void pch_msi_set_irq(struct kvm *kvm, int irq, int level)
> >> +int pch_msi_set_irq(struct kvm *kvm,
> >> + struct kvm_kernel_irq_routing_entry *e, int level)
> >> {
> >> - eiointc_set_irq(kvm->arch.eiointc, irq, level);
> >> + u64 msg_addr;
> >> +
> >> + msg_addr = (((u64)e->msi.address_hi) << 32) | e->msi.address_lo;
> > Define and evaluate at the same time.
> >
> Got it .
>
> Thanks.
> Song Gao
> > Huacai
> >
> >> + if (cpu_has_msgint && kvm->arch.dmsintc &&
> >> + msg_addr >= kvm->arch.dmsintc->msg_addr_base &&
> >> + msg_addr < (kvm->arch.dmsintc->msg_addr_base + kvm->arch.dmsintc->msg_addr_size)) {
> >> + return kvm_dmsintc_set_msi_irq(kvm, msg_addr, e->msi.data, level);
> >> + }
> >> +
> >> + eiointc_set_irq(kvm->arch.eiointc, e->msi.data, level);
> >> + return 0;
> >> }
> >>
> >> static int loongarch_pch_pic_read(struct loongarch_pch_pic *s, gpa_t addr, int len, void *val)
> >> diff --git a/arch/loongarch/kvm/interrupt.c b/arch/loongarch/kvm/interrupt.c
> >> index fb704f4c8ac5..32930959f7c2 100644
> >> --- a/arch/loongarch/kvm/interrupt.c
> >> +++ b/arch/loongarch/kvm/interrupt.c
> >> @@ -7,6 +7,7 @@
> >> #include <linux/errno.h>
> >> #include <asm/kvm_csr.h>
> >> #include <asm/kvm_vcpu.h>
> >> +#include <asm/kvm_dmsintc.h>
> >>
> >> static unsigned int priority_to_irq[EXCCODE_INT_NUM] = {
> >> [INT_TI] = CPU_TIMER,
> >> @@ -33,6 +34,7 @@ static int kvm_irq_deliver(struct kvm_vcpu *vcpu, unsigned int priority)
> >> irq = priority_to_irq[priority];
> >>
> >> if (kvm_guest_has_msgint(&vcpu->arch) && (priority == INT_AVEC)) {
> >> + dmsintc_inject_irq(vcpu);
> >> set_gcsr_estat(irq);
> >> return 1;
> >> }
> >> diff --git a/arch/loongarch/kvm/irqfd.c b/arch/loongarch/kvm/irqfd.c
> >> index 9a39627aecf0..308ef08b634c 100644
> >> --- a/arch/loongarch/kvm/irqfd.c
> >> +++ b/arch/loongarch/kvm/irqfd.c
> >> @@ -28,10 +28,7 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
> >> {
> >> if (!level)
> >> return -1;
> >> -
> >> - pch_msi_set_irq(kvm, e->msi.data, level);
> >> -
> >> - return 0;
> >> + return pch_msi_set_irq(kvm, e, level);
> >> }
> >>
> >> /*
> >> @@ -71,13 +68,15 @@ int kvm_set_routing_entry(struct kvm *kvm,
> >> int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
> >> struct kvm *kvm, int irq_source_id, int level, bool line_status)
> >> {
> >> + if (!level)
> >> + return -EWOULDBLOCK;
> >> +
> >> switch (e->type) {
> >> case KVM_IRQ_ROUTING_IRQCHIP:
> >> pch_pic_set_irq(kvm->arch.pch_pic, e->irqchip.pin, level);
> >> return 0;
> >> case KVM_IRQ_ROUTING_MSI:
> >> - pch_msi_set_irq(kvm, e->msi.data, level);
> >> - return 0;
> >> + return pch_msi_set_irq(kvm, e, level);
> >> default:
> >> return -EWOULDBLOCK;
> >> }
> >> --
> >> 2.39.3
> >>
> >>
>
>