| Message ID | 1467731491-6458-1-git-send-email-vijay.kilari@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Vijaya, On Tue, Jul 05, 2016 at 08:41:31PM +0530, vijay.kilari@gmail.com wrote: > From: Vijaya Kumar K <vijayak@caviumnetworks.com> > > The dist and redist regions are created and registered in > vgic_register_dist_iodevs() and vgic_v3_init_redist_iodev() > calls for distributor and redistributor respectively when > vgic_v3_map_resources() is called. This mapping of resources > is done when vcpu run ioctl is called. > > Below is the call stack of the same. > > [<ffff0000080b2e8c>] vgic_register_redist_iodevs+0x94/0x27c > [<ffff0000080b0fd8>] vgic_v3_map_resources+0x138/0x188 > [<ffff0000080affa4>] kvm_vgic_map_resources+0xb0/0xb8 > [<ffff0000080a3888>] kvm_arch_vcpu_ioctl_run+0x4a8/0x550 > [<ffff00000809c218>] kvm_vcpu_ioctl+0x304/0x74c > [<ffff000008232cac>] do_vfs_ioctl+0xc0/0x754 > [<ffff0000082333d0>] SyS_ioctl+0x90/0xa4 > [<ffff000008084af0>] el0_svc_naked+0x24/0x28 > > During live migration, the destination VM first restores the all the > GIC registers(dist, rdist and cpuif registers) using ioctl's before > resuming the VM.So no vcpu run ioctl is called untill complete > GIC context is restored. > > Hence, In case of live migration, when ioctls are called to write > dist/rdist registers the ioctls fails as > vcpu->kvm->arch.vgic.dist_iodev andkvm->arch.vgic.redist_iodevs > are NULL. > Is this for GICv3 only? Can you give me a more specific pointer to the place where this fails or a traceback? Definitely the approach of registering things early doesn't work, because it breaks all sorts of other things. So the trick is to make sure userspace accesses can work without a registers kvm iodev. I will have a look at this, but some more conceret info as requested above will be helpful. Thanks, -Christoffer
diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c index 0130c4b..cc843fe 100644 --- a/virt/kvm/arm/vgic/vgic-kvm-device.c +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c @@ -101,6 +101,25 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write) *addr = *addr_ptr; } +#ifdef CONFIG_KVM_ARM_VGIC_V3 + switch (type) { + case KVM_VGIC_V3_ADDR_TYPE_DIST: + r = vgic_register_dist_iodev(kvm, vgic->vgic_dist_base, VGIC_V3); + if (r) { + kvm_err("Unable to register VGICv3 dist MMIO regions\n"); + goto out; + } + break; + case KVM_VGIC_V3_ADDR_TYPE_REDIST: + r = vgic_register_redist_iodevs(kvm, vgic->vgic_redist_base); + if (r) { + kvm_err("Unable to register VGICv3 redist MMIO regions\n"); + goto out; + } + break; + } +#endif + out: mutex_unlock(&kvm->lock); return r; diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c index 346b4ad..a149b35 100644 --- a/virt/kvm/arm/vgic/vgic-v3.c +++ b/virt/kvm/arm/vgic/vgic-v3.c @@ -267,18 +267,6 @@ int vgic_v3_map_resources(struct kvm *kvm) goto out; } - ret = vgic_register_dist_iodev(kvm, dist->vgic_dist_base, VGIC_V3); - if (ret) { - kvm_err("Unable to register VGICv3 dist MMIO regions\n"); - goto out; - } - - ret = vgic_register_redist_iodevs(kvm, dist->vgic_redist_base); - if (ret) { - kvm_err("Unable to register VGICv3 redist MMIO regions\n"); - goto out; - } - dist->ready = true; out: