| Message ID | 20121110154259.2836.49857.stgit@chazy-air |
|---|---|
| State | New |
| Headers | show |
On Sat, Nov 10, 2012 at 03:42:59PM +0000, Christoffer Dall wrote: > From: Christoffer Dall <cdall@cs.columbia.edu> > > All interrupt injection is now based on the VM ioctl KVM_IRQ_LINE. This > works semantically well for the GIC as we in fact raise/lower a line on > a machine component (the gic). The IOCTL uses the follwing struct. > > struct kvm_irq_level { > union { > __u32 irq; /* GSI */ > __s32 status; /* not used for KVM_IRQ_LEVEL */ > }; > __u32 level; /* 0 or 1 */ > }; > > ARM can signal an interrupt either at the CPU level, or at the in-kernel irqchip > (GIC), and for in-kernel irqchip can tell the GIC to use PPIs designated for > specific cpus. The irq field is interpreted like this: > > bits: | 31 ... 24 | 23 ... 16 | 15 ... 0 | > field: | irq_type | vcpu_index | irq_number | > > The irq_type field has the following values: > - irq_type[0]: out-of-kernel GIC: irq_number 0 is IRQ, irq_number 1 is FIQ > - irq_type[1]: in-kernel GIC: SPI, irq_number between 32 and 1019 (incl.) > (the vcpu_index field is ignored) > - irq_type[2]: in-kernel GIC: PPI, irq_number between 16 and 31 (incl.) > > The irq_number thus corresponds to the irq ID in as in the GICv2 specs. > > This is documented in Documentation/kvm/api.txt. > > Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> > Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> [...] > diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c > index 5ac3132..15e2ab1 100644 > --- a/arch/arm/kvm/arm.c > +++ b/arch/arm/kvm/arm.c > @@ -24,6 +24,7 @@ > #include <linux/fs.h> > #include <linux/mman.h> > #include <linux/sched.h> > +#include <linux/kvm.h> > #include <trace/events/kvm.h> > > #define CREATE_TRACE_POINTS > @@ -272,6 +273,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) > > void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) > { > + vcpu->cpu = cpu; > } > > void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) > @@ -312,6 +314,74 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) > return -EINVAL; > } > > +static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level) > +{ > + int bit_index; > + bool set; > + unsigned long *ptr; > + > + if (number == KVM_ARM_IRQ_CPU_IRQ) > + bit_index = __ffs(HCR_VI); > + else /* KVM_ARM_IRQ_CPU_FIQ */ > + bit_index = __ffs(HCR_VF); > + > + ptr = (unsigned long *)&vcpu->arch.irq_lines; > + if (level) > + set = test_and_set_bit(bit_index, ptr); > + else > + set = test_and_clear_bit(bit_index, ptr); > + > + /* > + * If we didn't change anything, no need to wake up or kick other CPUs > + */ > + if (set == level) > + return 0; > + > + /* > + * The vcpu irq_lines field was updated, wake up sleeping VCPUs and > + * trigger a world-switch round on the running physical CPU to set the > + * virtual IRQ/FIQ fields in the HCR appropriately. > + */ > + kvm_vcpu_kick(vcpu); > + > + return 0; > +} > + > +int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) > +{ > + u32 irq = irq_level->irq; > + unsigned int irq_type, vcpu_idx, irq_num; > + int nrcpus = atomic_read(&kvm->online_vcpus); > + struct kvm_vcpu *vcpu = NULL; > + bool level = irq_level->level; > + > + irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; > + vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; > + irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; > + > + trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); > + > + if (irq_type == KVM_ARM_IRQ_TYPE_CPU || > + irq_type == KVM_ARM_IRQ_TYPE_PPI) { > + if (vcpu_idx >= nrcpus) > + return -EINVAL; > + > + vcpu = kvm_get_vcpu(kvm, vcpu_idx); > + if (!vcpu) > + return -EINVAL; > + } > + > + switch (irq_type) { > + case KVM_ARM_IRQ_TYPE_CPU: > + if (irq_num > KVM_ARM_IRQ_CPU_FIQ) > + return -EINVAL; > + > + return vcpu_interrupt_line(vcpu, irq_num, level); > + } > + > + return -EINVAL; > +} Holy cyclomatic complexity Batman! Any way this can be cleaned up? Will
On Mon, Nov 19, 2012 at 9:55 AM, Will Deacon <will.deacon@arm.com> wrote: > On Sat, Nov 10, 2012 at 03:42:59PM +0000, Christoffer Dall wrote: >> From: Christoffer Dall <cdall@cs.columbia.edu> >> >> All interrupt injection is now based on the VM ioctl KVM_IRQ_LINE. This >> works semantically well for the GIC as we in fact raise/lower a line on >> a machine component (the gic). The IOCTL uses the follwing struct. >> >> struct kvm_irq_level { >> union { >> __u32 irq; /* GSI */ >> __s32 status; /* not used for KVM_IRQ_LEVEL */ >> }; >> __u32 level; /* 0 or 1 */ >> }; >> >> ARM can signal an interrupt either at the CPU level, or at the in-kernel irqchip >> (GIC), and for in-kernel irqchip can tell the GIC to use PPIs designated for >> specific cpus. The irq field is interpreted like this: >> >> bits: | 31 ... 24 | 23 ... 16 | 15 ... 0 | >> field: | irq_type | vcpu_index | irq_number | >> >> The irq_type field has the following values: >> - irq_type[0]: out-of-kernel GIC: irq_number 0 is IRQ, irq_number 1 is FIQ >> - irq_type[1]: in-kernel GIC: SPI, irq_number between 32 and 1019 (incl.) >> (the vcpu_index field is ignored) >> - irq_type[2]: in-kernel GIC: PPI, irq_number between 16 and 31 (incl.) >> >> The irq_number thus corresponds to the irq ID in as in the GICv2 specs. >> >> This is documented in Documentation/kvm/api.txt. >> >> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> >> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> > > [...] > >> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c >> index 5ac3132..15e2ab1 100644 >> --- a/arch/arm/kvm/arm.c >> +++ b/arch/arm/kvm/arm.c >> @@ -24,6 +24,7 @@ >> #include <linux/fs.h> >> #include <linux/mman.h> >> #include <linux/sched.h> >> +#include <linux/kvm.h> >> #include <trace/events/kvm.h> >> >> #define CREATE_TRACE_POINTS >> @@ -272,6 +273,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) >> >> void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) >> { >> + vcpu->cpu = cpu; >> } >> >> void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) >> @@ -312,6 +314,74 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) >> return -EINVAL; >> } >> >> +static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level) >> +{ >> + int bit_index; >> + bool set; >> + unsigned long *ptr; >> + >> + if (number == KVM_ARM_IRQ_CPU_IRQ) >> + bit_index = __ffs(HCR_VI); >> + else /* KVM_ARM_IRQ_CPU_FIQ */ >> + bit_index = __ffs(HCR_VF); >> + >> + ptr = (unsigned long *)&vcpu->arch.irq_lines; >> + if (level) >> + set = test_and_set_bit(bit_index, ptr); >> + else >> + set = test_and_clear_bit(bit_index, ptr); >> + >> + /* >> + * If we didn't change anything, no need to wake up or kick other CPUs >> + */ >> + if (set == level) >> + return 0; >> + >> + /* >> + * The vcpu irq_lines field was updated, wake up sleeping VCPUs and >> + * trigger a world-switch round on the running physical CPU to set the >> + * virtual IRQ/FIQ fields in the HCR appropriately. >> + */ >> + kvm_vcpu_kick(vcpu); >> + >> + return 0; >> +} >> + >> +int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) >> +{ >> + u32 irq = irq_level->irq; >> + unsigned int irq_type, vcpu_idx, irq_num; >> + int nrcpus = atomic_read(&kvm->online_vcpus); >> + struct kvm_vcpu *vcpu = NULL; >> + bool level = irq_level->level; >> + >> + irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; >> + vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; >> + irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; >> + >> + trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); >> + >> + if (irq_type == KVM_ARM_IRQ_TYPE_CPU || >> + irq_type == KVM_ARM_IRQ_TYPE_PPI) { >> + if (vcpu_idx >= nrcpus) >> + return -EINVAL; >> + >> + vcpu = kvm_get_vcpu(kvm, vcpu_idx); >> + if (!vcpu) >> + return -EINVAL; >> + } >> + >> + switch (irq_type) { >> + case KVM_ARM_IRQ_TYPE_CPU: >> + if (irq_num > KVM_ARM_IRQ_CPU_FIQ) >> + return -EINVAL; >> + >> + return vcpu_interrupt_line(vcpu, irq_num, level); >> + } >> + >> + return -EINVAL; >> +} > > Holy cyclomatic complexity Batman! Any way this can be cleaned up? > you mean the interface or the implementation of kvm_vm_ioctl_irq_line? If the latter, there's just a lot of bits to decode here. Thanks, -Christoffer
On Mon, Nov 19, 2012 at 03:04:38PM +0000, Christoffer Dall wrote: > On Mon, Nov 19, 2012 at 9:55 AM, Will Deacon <will.deacon@arm.com> wrote: > > On Sat, Nov 10, 2012 at 03:42:59PM +0000, Christoffer Dall wrote: > >> +int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) > >> +{ > >> + u32 irq = irq_level->irq; > >> + unsigned int irq_type, vcpu_idx, irq_num; > >> + int nrcpus = atomic_read(&kvm->online_vcpus); > >> + struct kvm_vcpu *vcpu = NULL; > >> + bool level = irq_level->level; > >> + > >> + irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; > >> + vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; > >> + irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; > >> + > >> + trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); > >> + > >> + if (irq_type == KVM_ARM_IRQ_TYPE_CPU || > >> + irq_type == KVM_ARM_IRQ_TYPE_PPI) { > >> + if (vcpu_idx >= nrcpus) > >> + return -EINVAL; > >> + > >> + vcpu = kvm_get_vcpu(kvm, vcpu_idx); > >> + if (!vcpu) > >> + return -EINVAL; > >> + } > >> + > >> + switch (irq_type) { > >> + case KVM_ARM_IRQ_TYPE_CPU: > >> + if (irq_num > KVM_ARM_IRQ_CPU_FIQ) > >> + return -EINVAL; > >> + > >> + return vcpu_interrupt_line(vcpu, irq_num, level); > >> + } > >> + > >> + return -EINVAL; > >> +} > > > > Holy cyclomatic complexity Batman! Any way this can be cleaned up? > > > you mean the interface or the implementation of kvm_vm_ioctl_irq_line? > If the latter, there's just a lot of bits to decode here. I just think that this function is incredibly hard to read: different nested conditions under duplicate checks of the same variables which differ between an if(...) and a switch(...). I appreciate that it's a complex problem, which is why I helpfully didn't suggest an alternative! There must be *something* we can do though. Will
On Mon, Nov 19, 2012 at 10:26 AM, Will Deacon <will.deacon@arm.com> wrote: > On Mon, Nov 19, 2012 at 03:04:38PM +0000, Christoffer Dall wrote: >> On Mon, Nov 19, 2012 at 9:55 AM, Will Deacon <will.deacon@arm.com> wrote: >> > On Sat, Nov 10, 2012 at 03:42:59PM +0000, Christoffer Dall wrote: >> >> +int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) >> >> +{ >> >> + u32 irq = irq_level->irq; >> >> + unsigned int irq_type, vcpu_idx, irq_num; >> >> + int nrcpus = atomic_read(&kvm->online_vcpus); >> >> + struct kvm_vcpu *vcpu = NULL; >> >> + bool level = irq_level->level; >> >> + >> >> + irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; >> >> + vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; >> >> + irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; >> >> + >> >> + trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); >> >> + >> >> + if (irq_type == KVM_ARM_IRQ_TYPE_CPU || >> >> + irq_type == KVM_ARM_IRQ_TYPE_PPI) { >> >> + if (vcpu_idx >= nrcpus) >> >> + return -EINVAL; >> >> + >> >> + vcpu = kvm_get_vcpu(kvm, vcpu_idx); >> >> + if (!vcpu) >> >> + return -EINVAL; >> >> + } >> >> + >> >> + switch (irq_type) { >> >> + case KVM_ARM_IRQ_TYPE_CPU: >> >> + if (irq_num > KVM_ARM_IRQ_CPU_FIQ) >> >> + return -EINVAL; >> >> + >> >> + return vcpu_interrupt_line(vcpu, irq_num, level); >> >> + } >> >> + >> >> + return -EINVAL; >> >> +} >> > >> > Holy cyclomatic complexity Batman! Any way this can be cleaned up? >> > >> you mean the interface or the implementation of kvm_vm_ioctl_irq_line? >> If the latter, there's just a lot of bits to decode here. > > I just think that this function is incredibly hard to read: different nested > conditions under duplicate checks of the same variables which differ between > an if(...) and a switch(...). I appreciate that it's a complex problem, > which is why I helpfully didn't suggest an alternative! There must be > *something* we can do though. > It is indeed a bit hard to read, but then wait to see the vgic code ! :) In all seriousness, I will unite myself with an alcoholic beverage one of these evenings and try to see what I can do about it, maybe split it up somehow, I'll give it a shot. Cheers, -Christoffer
On Mon, Nov 19, 2012 at 04:09:06PM +0000, Christoffer Dall wrote: > On Mon, Nov 19, 2012 at 10:26 AM, Will Deacon <will.deacon@arm.com> wrote: > > On Mon, Nov 19, 2012 at 03:04:38PM +0000, Christoffer Dall wrote: > In all seriousness, I will unite myself with an alcoholic beverage one > of these evenings and try to see what I can do about it, maybe split > it up somehow, I'll give it a shot. So this might be to do with the way you've split up the patches (likely I'll have similar complaints against the vGIC code, but at least it will make sense there!)... > >> >> +int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) > >> >> +{ > >> >> + u32 irq = irq_level->irq; > >> >> + unsigned int irq_type, vcpu_idx, irq_num; > >> >> + int nrcpus = atomic_read(&kvm->online_vcpus); > >> >> + struct kvm_vcpu *vcpu = NULL; > >> >> + bool level = irq_level->level; > >> >> + > >> >> + irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; > >> >> + vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; > >> >> + irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; > >> >> + > >> >> + trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); > >> >> + > >> >> + if (irq_type == KVM_ARM_IRQ_TYPE_CPU || > >> >> + irq_type == KVM_ARM_IRQ_TYPE_PPI) { > >> >> + if (vcpu_idx >= nrcpus) > >> >> + return -EINVAL; > >> >> + > >> >> + vcpu = kvm_get_vcpu(kvm, vcpu_idx); > >> >> + if (!vcpu) > >> >> + return -EINVAL; > >> >> + } > >> >> + > >> >> + switch (irq_type) { > >> >> + case KVM_ARM_IRQ_TYPE_CPU: > >> >> + if (irq_num > KVM_ARM_IRQ_CPU_FIQ) > >> >> + return -EINVAL; > >> >> + > >> >> + return vcpu_interrupt_line(vcpu, irq_num, level); > >> >> + } > >> >> + > >> >> + return -EINVAL; > >> >> +} This obviously doesn't handle PPIs, which is where the confusion lies. You can just as easily write it as: int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) { u32 irq = irq_level->irq; unsigned int irq_type, vcpu_idx, irq_num; int nrcpus = atomic_read(&kvm->online_vcpus); struct kvm_vcpu *vcpu = NULL; bool level = irq_level->level; irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); if (irq_type != KVM_ARM_IRQ_TYPE_CPU) return -EINVAL; if (vcpu_idx >= nrcpus) return -EINVAL; vcpu = kvm_get_vcpu(kvm, vcpu_idx); if (!vcpu) return -EINVAL; if (irq_num > KVM_ARM_IRQ_CPU_FIQ) return -EINVAL; return vcpu_interrupt_line(vcpu, irq_num, level); } Then add all the IRQ complexity in a later patch! Will
On Mon, Nov 19, 2012 at 11:21 AM, Will Deacon <will.deacon@arm.com> wrote: > On Mon, Nov 19, 2012 at 04:09:06PM +0000, Christoffer Dall wrote: >> On Mon, Nov 19, 2012 at 10:26 AM, Will Deacon <will.deacon@arm.com> wrote: >> > On Mon, Nov 19, 2012 at 03:04:38PM +0000, Christoffer Dall wrote: >> In all seriousness, I will unite myself with an alcoholic beverage one >> of these evenings and try to see what I can do about it, maybe split >> it up somehow, I'll give it a shot. > > So this might be to do with the way you've split up the patches (likely I'll > have similar complaints against the vGIC code, but at least it will make > sense there!)... > >> >> >> +int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) >> >> >> +{ >> >> >> + u32 irq = irq_level->irq; >> >> >> + unsigned int irq_type, vcpu_idx, irq_num; >> >> >> + int nrcpus = atomic_read(&kvm->online_vcpus); >> >> >> + struct kvm_vcpu *vcpu = NULL; >> >> >> + bool level = irq_level->level; >> >> >> + >> >> >> + irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; >> >> >> + vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; >> >> >> + irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; >> >> >> + >> >> >> + trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); >> >> >> + >> >> >> + if (irq_type == KVM_ARM_IRQ_TYPE_CPU || >> >> >> + irq_type == KVM_ARM_IRQ_TYPE_PPI) { >> >> >> + if (vcpu_idx >= nrcpus) >> >> >> + return -EINVAL; >> >> >> + >> >> >> + vcpu = kvm_get_vcpu(kvm, vcpu_idx); >> >> >> + if (!vcpu) >> >> >> + return -EINVAL; >> >> >> + } >> >> >> + >> >> >> + switch (irq_type) { >> >> >> + case KVM_ARM_IRQ_TYPE_CPU: >> >> >> + if (irq_num > KVM_ARM_IRQ_CPU_FIQ) >> >> >> + return -EINVAL; >> >> >> + >> >> >> + return vcpu_interrupt_line(vcpu, irq_num, level); >> >> >> + } >> >> >> + >> >> >> + return -EINVAL; >> >> >> +} > > This obviously doesn't handle PPIs, which is where the confusion lies. You > can just as easily write it as: > > int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) > { > u32 irq = irq_level->irq; > unsigned int irq_type, vcpu_idx, irq_num; > int nrcpus = atomic_read(&kvm->online_vcpus); > struct kvm_vcpu *vcpu = NULL; > bool level = irq_level->level; > > irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; > vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; > irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; > > trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); > > if (irq_type != KVM_ARM_IRQ_TYPE_CPU) > return -EINVAL; > > if (vcpu_idx >= nrcpus) > return -EINVAL; > > vcpu = kvm_get_vcpu(kvm, vcpu_idx); > if (!vcpu) > return -EINVAL; > > if (irq_num > KVM_ARM_IRQ_CPU_FIQ) > return -EINVAL; > > return vcpu_interrupt_line(vcpu, irq_num, level); > } > > Then add all the IRQ complexity in a later patch! > that was pretty constructive, I did just that. Thanks.
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 2a5dc41..845ceda 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -615,15 +615,32 @@ created. 4.25 KVM_IRQ_LINE Capability: KVM_CAP_IRQCHIP -Architectures: x86, ia64 +Architectures: x86, ia64, arm Type: vm ioctl Parameters: struct kvm_irq_level Returns: 0 on success, -1 on error Sets the level of a GSI input to the interrupt controller model in the kernel. -Requires that an interrupt controller model has been previously created with -KVM_CREATE_IRQCHIP. Note that edge-triggered interrupts require the level -to be set to 1 and then back to 0. +On some architectures it is required that an interrupt controller model has +been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered +interrupts require the level to be set to 1 and then back to 0. + +ARM can signal an interrupt either at the CPU level, or at the in-kernel irqchip +(GIC), and for in-kernel irqchip can tell the GIC to use PPIs designated for +specific cpus. The irq field is interpreted like this: + + bits: | 31 ... 24 | 23 ... 16 | 15 ... 0 | + field: | irq_type | vcpu_index | irq_id | + +The irq_type field has the following values: +- irq_type[0]: out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ +- irq_type[1]: in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.) + (the vcpu_index field is ignored) +- irq_type[2]: in-kernel GIC: PPI, irq_id between 16 and 31 (incl.) + +(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs) + +In both cases, level is used to raise/lower the line. struct kvm_irq_level { union { diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index f6e8f6f..4f54cda 100644 --- a/arch/arm/include/asm/kvm_arm.h +++ b/arch/arm/include/asm/kvm_arm.h @@ -68,6 +68,7 @@ #define HCR_GUEST_MASK (HCR_TSC | HCR_TSW | HCR_TWI | HCR_VM | HCR_BSU_IS | \ HCR_FB | HCR_TAC | HCR_AMO | HCR_IMO | HCR_FMO | \ HCR_SWIO | HCR_TIDCP) +#define HCR_VIRT_EXCP_MASK (HCR_VA | HCR_VI | HCR_VF) /* Hyp System Control Register (HSCTLR) bits */ #define HSCTLR_TE (1 << 30) diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 00d61a6..a807d9a 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -23,6 +23,7 @@ #include <asm/ptrace.h> #define __KVM_HAVE_GUEST_DEBUG +#define __KVM_HAVE_IRQ_LINE #define KVM_REG_SIZE(id) \ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) @@ -79,4 +80,24 @@ struct kvm_arch_memory_slot { #define KVM_REG_ARM_CORE (0x0010 << KVM_REG_ARM_COPROC_SHIFT) #define KVM_REG_ARM_CORE_REG(name) (offsetof(struct kvm_regs, name) / 4) +/* KVM_IRQ_LINE irq field index values */ +#define KVM_ARM_IRQ_TYPE_SHIFT 24 +#define KVM_ARM_IRQ_TYPE_MASK 0xff +#define KVM_ARM_IRQ_VCPU_SHIFT 16 +#define KVM_ARM_IRQ_VCPU_MASK 0xff +#define KVM_ARM_IRQ_NUM_SHIFT 0 +#define KVM_ARM_IRQ_NUM_MASK 0xffff + +/* irq_type field */ +#define KVM_ARM_IRQ_TYPE_CPU 0 +#define KVM_ARM_IRQ_TYPE_SPI 1 +#define KVM_ARM_IRQ_TYPE_PPI 2 + +/* out-of-kernel GIC cpu interrupt injection irq_number field */ +#define KVM_ARM_IRQ_CPU_IRQ 0 +#define KVM_ARM_IRQ_CPU_FIQ 1 + +/* Highest supported SPI, from VGIC_NR_IRQS */ +#define KVM_ARM_IRQ_GIC_MAX 127 + #endif /* __ARM_KVM_H__ */ diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 5ac3132..15e2ab1 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -24,6 +24,7 @@ #include <linux/fs.h> #include <linux/mman.h> #include <linux/sched.h> +#include <linux/kvm.h> #include <trace/events/kvm.h> #define CREATE_TRACE_POINTS @@ -272,6 +273,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { + vcpu->cpu = cpu; } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) @@ -312,6 +314,74 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) return -EINVAL; } +static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level) +{ + int bit_index; + bool set; + unsigned long *ptr; + + if (number == KVM_ARM_IRQ_CPU_IRQ) + bit_index = __ffs(HCR_VI); + else /* KVM_ARM_IRQ_CPU_FIQ */ + bit_index = __ffs(HCR_VF); + + ptr = (unsigned long *)&vcpu->arch.irq_lines; + if (level) + set = test_and_set_bit(bit_index, ptr); + else + set = test_and_clear_bit(bit_index, ptr); + + /* + * If we didn't change anything, no need to wake up or kick other CPUs + */ + if (set == level) + return 0; + + /* + * The vcpu irq_lines field was updated, wake up sleeping VCPUs and + * trigger a world-switch round on the running physical CPU to set the + * virtual IRQ/FIQ fields in the HCR appropriately. + */ + kvm_vcpu_kick(vcpu); + + return 0; +} + +int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) +{ + u32 irq = irq_level->irq; + unsigned int irq_type, vcpu_idx, irq_num; + int nrcpus = atomic_read(&kvm->online_vcpus); + struct kvm_vcpu *vcpu = NULL; + bool level = irq_level->level; + + irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; + vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; + irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; + + trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); + + if (irq_type == KVM_ARM_IRQ_TYPE_CPU || + irq_type == KVM_ARM_IRQ_TYPE_PPI) { + if (vcpu_idx >= nrcpus) + return -EINVAL; + + vcpu = kvm_get_vcpu(kvm, vcpu_idx); + if (!vcpu) + return -EINVAL; + } + + switch (irq_type) { + case KVM_ARM_IRQ_TYPE_CPU: + if (irq_num > KVM_ARM_IRQ_CPU_FIQ) + return -EINVAL; + + return vcpu_interrupt_line(vcpu, irq_num, level); + } + + return -EINVAL; +} + long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h index 862b2cc..105d1f7 100644 --- a/arch/arm/kvm/trace.h +++ b/arch/arm/kvm/trace.h @@ -39,6 +39,31 @@ TRACE_EVENT(kvm_exit, TP_printk("PC: 0x%08lx", __entry->vcpu_pc) ); +TRACE_EVENT(kvm_irq_line, + TP_PROTO(unsigned int type, int vcpu_idx, int irq_num, int level), + TP_ARGS(type, vcpu_idx, irq_num, level), + + TP_STRUCT__entry( + __field( unsigned int, type ) + __field( int, vcpu_idx ) + __field( int, irq_num ) + __field( int, level ) + ), + + TP_fast_assign( + __entry->type = type; + __entry->vcpu_idx = vcpu_idx; + __entry->irq_num = irq_num; + __entry->level = level; + ), + + TP_printk("Inject %s interrupt (%d), vcpu->idx: %d, num: %d, level: %d", + (__entry->type == KVM_ARM_IRQ_TYPE_CPU) ? "CPU" : + (__entry->type == KVM_ARM_IRQ_TYPE_PPI) ? "VGIC PPI" : + (__entry->type == KVM_ARM_IRQ_TYPE_SPI) ? "VGIC SPI" : "UNKNOWN", + __entry->type, __entry->vcpu_idx, __entry->irq_num, __entry->level) +); + TRACE_EVENT(kvm_unmap_hva, TP_PROTO(unsigned long hva), TP_ARGS(hva), diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index ad15f10..1db0460 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -115,6 +115,7 @@ struct kvm_irq_level { * ACPI gsi notion of irq. * For IA-64 (APIC model) IOAPIC0: irq 0-23; IOAPIC1: irq 24-47.. * For X86 (standard AT mode) PIC0/1: irq 0-15. IOAPIC0: 0-23.. + * For ARM: See Documentation/virtual/kvm/api.txt */ union { __u32 irq;