[RFC PATCH v3 6/6] kvm/ppc/mpic: add KVM_CAP_IRQ_MPIC

Scott Wood
2013-04-03T01:57:53Z

Enabling this capability connects the vcpu to the designated in-kernel
MPIC. Using explicit connections between vcpus and irqchips allows
for flexibility, but the main benefit at the moment is that it
simplifies the code -- KVM doesn't need vm-global state to remember
which MPIC object is associated with this vm, and it doesn't need to
care about ordering between irqchip creation and vcpu creation.

Signed-off-by: Scott Wood <scottwood@freescale.com>
---
Documentation/virtual/kvm/api.txt | 8 ++++++
arch/powerpc/include/asm/kvm_host.h | 8 ++++++
arch/powerpc/include/asm/kvm_ppc.h | 2 ++
arch/powerpc/kvm/booke.c | 4 ++-
arch/powerpc/kvm/mpic.c | 49 +++++++++++++++++++++++++++++++----
arch/powerpc/kvm/powerpc.c | 26 +++++++++++++++++++
include/uapi/linux/kvm.h | 1 +
7 files changed, 92 insertions(+), 6 deletions(-)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index d52f3f9..4c326ae 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2728,3 +2728,11 @@ to receive the topmost interrupt vector.
When disabled (args[0] = 0), behavior is as if this facility is unsupported.

When this capability is enabled, KVM_EXIT_EPR can occur.
+
+6.6 KVM_CAP_IRQ_MPIC
+
+Architectures: ppc
+Parameters: args[0] is the MPIC device fd
+ args[1] is the MPIC CPU number for this vcpu
+
+This capability connects the vcpu to an in-kernel MPIC device.
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 7e7aef9..2a2e235 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -375,6 +375,11 @@ struct kvmppc_booke_debug_reg {
u64 dac[KVMPPC_BOOKE_MAX_DAC];
};

+#define KVMPPC_IRQ_DEFAULT 0
+#define KVMPPC_IRQ_MPIC 1
+
+struct openpic;
+
struct kvm_vcpu_arch {
ulong host_stack;
u32 host_pid;
@@ -554,6 +559,9 @@ struct kvm_vcpu_arch {
unsigned long magic_page_pa; /* phys addr to map the magic page to */
unsigned long magic_page_ea; /* effect. addr to map the magic page to */

+ int irq_type; /* one of KVM_IRQ_* */
+ struct openpic *mpic; /* KVM_IRQ_MPIC */
+
#ifdef CONFIG_KVM_BOOK3S_64_HV
struct kvm_vcpu_arch_shared shregs;

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 3b63b97..f54707f 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -276,6 +276,8 @@ static inline void kvmppc_set_epr(struct kvm_vcpu *vcpu, u32 epr)
}

void kvmppc_mpic_set_epr(struct kvm_vcpu *vcpu);
+int kvmppc_mpic_connect_vcpu(struct file *mpic_filp, struct kvm_vcpu *vcpu,
+ u32 cpu);

int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,
struct kvm_config_tlb *cfg);
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index cddc6b3..7d00222 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -430,8 +430,10 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
if (update_epr = true) {
if (vcpu->arch.epr_flags & KVMPPC_EPR_USER)
kvm_make_request(KVM_REQ_EPR_EXIT, vcpu);
- else if (vcpu->arch.epr_flags & KVMPPC_EPR_KERNEL)
+ else if (vcpu->arch.epr_flags & KVMPPC_EPR_KERNEL) {
+ BUG_ON(vcpu->arch.irq_type != KVMPPC_IRQ_MPIC);
kvmppc_mpic_set_epr(vcpu);
+ }
}

new_msr &= msr_mask;
diff --git a/arch/powerpc/kvm/mpic.c b/arch/powerpc/kvm/mpic.c
index 8cda2fa..caffe3b 100644
--- a/arch/powerpc/kvm/mpic.c
+++ b/arch/powerpc/kvm/mpic.c
@@ -1159,7 +1159,7 @@ static uint32_t openpic_iack(struct openpic *opp, struct irq_dest *dst,

void kvmppc_mpic_set_epr(struct kvm_vcpu *vcpu)
{
- struct openpic *opp = vcpu->arch.irqchip_priv;
+ struct openpic *opp = vcpu->arch.mpic;
int cpu = vcpu->vcpu_id;
unsigned long flags;

@@ -1442,10 +1442,10 @@ static void map_mmio(struct openpic *opp)

static void unmap_mmio(struct openpic *opp)
{
- BUG_ON(opp->mmio_mapped);
- opp->mmio_mapped = false;
-
- kvm_io_bus_unregister_dev(opp->kvm, KVM_MMIO_BUS, &opp->mmio);
+ if (opp->mmio_mapped) {
+ opp->mmio_mapped = false;
+ kvm_io_bus_unregister_dev(opp->kvm, KVM_MMIO_BUS, &opp->mmio);
+ }
}

static int set_base_addr(struct openpic *opp, struct kvm_device_attr *attr)
@@ -1681,6 +1681,45 @@ static const struct file_operations kvm_mpic_fops = {
.release = kvm_mpic_release,
};

+int kvmppc_mpic_connect_vcpu(struct file *mpic_filp, struct kvm_vcpu *vcpu,
+ u32 cpu)
+{
+ struct openpic *opp = mpic_filp->private_data;
+ int ret = 0;
+
+ if (mpic_filp->f_op != &kvm_mpic_fops)
+ return -EPERM;
+ if (opp->kvm != vcpu->kvm)
+ return -EPERM;
+ if (cpu < 0 || cpu >= MAX_CPU)
+ return -EPERM;
+
+ spin_lock_irq(&opp->lock);
+
+ if (opp->dst[cpu].vcpu) {
+ ret = -EEXIST;
+ goto out;
+ }
+ if (vcpu->arch.irq_type) {
+ return -EBUSY;
+ goto out;
+ }
+
+ opp->dst[cpu].vcpu = vcpu;
+ opp->nb_cpus = max(opp->nb_cpus, cpu + 1);
+
+ vcpu->arch.mpic = opp;
+ vcpu->arch.irq_type = KVMPPC_IRQ_MPIC;
+ atomic_inc(&opp->users);
+
+ if (opp->mpic_mode_mask = GCR_MODE_PROXY)
+ vcpu->arch.epr_flags |= KVMPPC_EPR_KERNEL;
+
+out:
+ spin_unlock_irq(&opp->lock);
+ return ret;
+}
+
int kvm_create_mpic(struct kvm *kvm, u32 type)
{
struct openpic *opp;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index c9a2972..290a905 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -25,6 +25,7 @@
#include <linux/hrtimer.h>
#include <linux/fs.h>
#include <linux/slab.h>
+#include <linux/file.h>
#include <asm/cputable.h>
#include <asm/uaccess.h>
#include <asm/kvm_ppc.h>
@@ -327,6 +328,9 @@ int kvm_dev_ioctl_check_extension(long ext)
#if defined(CONFIG_KVM_E500V2) || defined(CONFIG_KVM_E500MC)
case KVM_CAP_SW_TLB:
#endif
+#ifdef CONFIG_KVM_MPIC
+ case KVM_CAP_IRQ_MPIC:
+#endif
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
@@ -460,6 +464,13 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
tasklet_kill(&vcpu->arch.tasklet);

kvmppc_remove_vcpu_debugfs(vcpu);
+
+ switch (vcpu->arch.irq_type) {
+ case KVMPPC_IRQ_MPIC:
+ kvmppc_mpic_put(vcpu->arch.mpic);
+ break;
+ }
+
kvmppc_core_vcpu_free(vcpu);
}

@@ -794,6 +805,21 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
break;
}
#endif
+#ifdef CONFIG_KVM_MPIC
+ case KVM_CAP_IRQ_MPIC: {
+ struct file *filp;
+
+ r = -EBADF;
+ filp = fget(cap->args[0]);
+ if (!filp)
+ break;
+
+ r = kvmppc_mpic_connect_vcpu(filp, vcpu, cap->args[1]);
+
+ fput(filp);
+ break;
+ }
+#endif
default:
r = -EINVAL;
break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index d8f44ef..22fce7b 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -669,6 +669,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_ARM_PSCI 87
#define KVM_CAP_ARM_SET_DEVICE_ADDR 88
#define KVM_CAP_DEVICE_CTRL 89
+#define KVM_CAP_IRQ_MPIC 90

#ifdef KVM_CAP_IRQ_ROUTING

--
1.7.9.5