Re: [PATCH 2/7] kvm/vfio: detect assigned device via irqbypass manager
From: Alex Williamson <hidden>
Date: 2020-07-12 15:29:16
Also in:
kvm, virtualization
On Sun, 12 Jul 2020 22:49:21 +0800 Zhu Lingshan [off-list ref] wrote:
We used to detect assigned device via VFIO manipulated device conters. This is less flexible consider VFIO is not the only interface for assigned device. vDPA devices has dedicated backed hardware as well. So this patch tries to detect the assigned device via irqbypass manager. We will increase/decrease the assigned device counter in kvm/x86. Both vDPA and VFIO would go through this code path. This code path only affect x86 for now.
No it doesn't, it only adds VFIO support to x86, but it removes it from architecture neutral code. Also a VFIO device does not necessarily make use of the irqbypass manager, this depends on platform support and enablement of this feature. Therefore, NAK. Thanks, Alex
quoted hunk
Signed-off-by: Zhu Lingshan <redacted> --- arch/x86/kvm/x86.c | 10 ++++++++-- virt/kvm/vfio.c | 2 -- 2 files changed, 8 insertions(+), 4 deletions(-)diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 00c88c2..20c07d3 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c@@ -10624,11 +10624,17 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons, { struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); + int ret; irqfd->producer = prod; + kvm_arch_start_assignment(irqfd->kvm); + ret = kvm_x86_ops.update_pi_irte(irqfd->kvm, + prod->irq, irqfd->gsi, 1); + + if (ret) + kvm_arch_end_assignment(irqfd->kvm); - return kvm_x86_ops.update_pi_irte(irqfd->kvm, - prod->irq, irqfd->gsi, 1); + return ret; } void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c index 8fcbc50..111da52 100644 --- a/virt/kvm/vfio.c +++ b/virt/kvm/vfio.c@@ -226,7 +226,6 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) list_add_tail(&kvg->node, &kv->group_list); kvg->vfio_group = vfio_group; - kvm_arch_start_assignment(dev->kvm); mutex_unlock(&kv->lock);@@ -254,7 +253,6 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) continue; list_del(&kvg->node); - kvm_arch_end_assignment(dev->kvm); #ifdef CONFIG_SPAPR_TCE_IOMMU kvm_spapr_tce_release_vfio_group(dev->kvm, kvg->vfio_group);