From: Eran Borovik <borove@xxxxxxxxxx>
This patch adds modifications to allow correct
balloon operation when a virtual guest uses a direct assigned device.
The modifications include a new interface between qemu and kvm to allow
mapping and unmapping the pages from the IOMMU as well as pinning and unpinning as needed.
Signed-off-by: Eran Borovik <borove@xxxxxxxxxx>
---
hw/virtio-balloon.c | 13 ++++++++++---
kvm/include/linux/kvm.h | 2 ++
kvm/libkvm/libkvm.h | 4 ++++
qemu-kvm.c | 10 ++++++++++
qemu-kvm.h | 4 ++++
5 files changed, 30 insertions(+), 3 deletions(-)
diff --git a/hw/virtio-balloon.c b/hw/virtio-balloon.c
index 3792012..337f717 100644
--- a/hw/virtio-balloon.c
+++ b/hw/virtio-balloon.c
@@ -132,6 +132,7 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
elem.out_sg, elem.out_num) == 4) {
ram_addr_t pa;
ram_addr_t addr;
+ bool deflate;
pa = (ram_addr_t)ldl_p(&pfn) << VIRTIO_BALLOON_PFN_SHIFT;
offset += 4;
@@ -139,12 +140,18 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
addr = cpu_get_physical_page_desc(pa);
if ((addr & ~TARGET_PAGE_MASK) != IO_MEM_RAM)
continue;
+ deflate = !!(vq == s->dvq);
+# ifdef KVM_CAP_DEVICE_ASSIGNMENT
+ if (deflate)
+ kvm_map_pfn(NULL, pfn);
+ else
+ kvm_unmap_pfn(NULL, pfn);
+# endif
/* Using qemu_get_ram_ptr is bending the rules a bit, but
should be OK because we only want a single page. */
- balloon_page(qemu_get_ram_ptr(addr), !!(vq == s->dvq));
- }
-
+ balloon_page(qemu_get_ram_ptr(addr), deflate);
+ }
virtqueue_push(vq, &elem, offset);
virtio_notify(vdev, vq);
}
diff --git a/kvm/include/linux/kvm.h b/kvm/include/linux/kvm.h
index 6485981..90f7723 100644
--- a/kvm/include/linux/kvm.h
+++ b/kvm/include/linux/kvm.h
@@ -595,6 +595,8 @@ struct kvm_clock_data {
struct kvm_userspace_memory_region)
#define KVM_SET_TSS_ADDR _IO(KVMIO, 0x47)
#define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO, 0x48, __u64)
+#define KVM_IOMMU_UNMAP_PAGE _IOW(KVMIO, 0x49, __u64)
+#define KVM_IOMMU_MAP_PAGE _IOW(KVMIO, 0x50, __u64)
/* Device model IOC */
#define KVM_CREATE_IRQCHIP _IO(KVMIO, 0x60)
#define KVM_IRQ_LINE _IOW(KVMIO, 0x61, struct kvm_irq_level)
diff --git a/kvm/libkvm/libkvm.h b/kvm/libkvm/libkvm.h
index 4821a1e..7fa83b5 100644
--- a/kvm/libkvm/libkvm.h
+++ b/kvm/libkvm/libkvm.h
@@ -714,6 +714,10 @@ int kvm_s390_store_status(kvm_context_t kvm, int slot, unsigned long addr);
int kvm_assign_pci_device(kvm_context_t kvm,
struct kvm_assigned_pci_dev *assigned_dev);
+int kvm_deflate_pfn(kvm_context_t kvm, uint32_t pfn);
+
+int kvm_inflate_pfn(kvm_context_t kvm, uint32_t pfn);
+
/*!
* \brief Assign IRQ for an assigned device
*
diff --git a/qemu-kvm.c b/qemu-kvm.c
index a305907..a5ca029 100644
--- a/qemu-kvm.c
+++ b/qemu-kvm.c
@@ -1081,6 +1081,16 @@ static int kvm_old_assign_irq(kvm_context_t kvm,
return kvm_vm_ioctl(kvm_state, KVM_ASSIGN_IRQ, assigned_irq);
}
+int kvm_unmap_pfn(kvm_context_t kvm, uint32_t pfn)
+{
+ return kvm_vm_ioctl(kvm_state, KVM_IOMMU_UNMAP_PAGE, pfn);
+}
+
+int kvm_map_pfn(kvm_context_t kvm, uint32_t pfn)
+{
+ return kvm_vm_ioctl(kvm_state, KVM_IOMMU_MAP_PAGE, pfn);
+}
+
#ifdef KVM_CAP_ASSIGN_DEV_IRQ
int kvm_assign_irq(kvm_context_t kvm, struct kvm_assigned_irq *assigned_irq)
{
diff --git a/qemu-kvm.h b/qemu-kvm.h
index 6b3e5a1..861c336 100644
--- a/qemu-kvm.h
+++ b/qemu-kvm.h
@@ -691,6 +691,10 @@ int kvm_s390_store_status(kvm_context_t kvm, int slot, unsigned long addr);
int kvm_assign_pci_device(kvm_context_t kvm,
struct kvm_assigned_pci_dev *assigned_dev);
+int kvm_unmap_pfn(kvm_context_t kvm, uint32_t pfn);
+
+int kvm_map_pfn(kvm_context_t kvm, uint32_t pfn);
+
/*!
* \brief Assign IRQ for an assigned device
*
--
1.6.0.4
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