From: wei qi <weiqi4@xxxxxxxxxx>
I just implemented dynamically updating the iommu table to support pass-through,
It seen to work fine.
Test:
start a 4G vm with 2M hugetlb and ixgbevf passthrough,
GuestOS: linux-5.2.6 + (mm / virtio: Provide support for free page reporting)
HostOS: 5.5-rc4
Host: Intel(R) Xeon(R) Gold 6161 CPU @ 2.20GHz
after enable page hinting, free pages at GuestOS can be free at host.
before,
# cat /sys/devices/system/node/node*/hugepages/hugepages-2048kB/free_hugepages
5620
5620
after start VM,
# numastat -c qemu
Per-node process memory usage (in MBs)
PID Node 0 Node 1 Total
--------------- ------ ------ -----
24463 (qemu_hotr 6 6 12
24479 (qemu_tls_ 0 8 8
70718 (qemu-syst 58 539 597
--------------- ------ ------ -----
Total 64 553 616
# cat /sys/devices/system/node/node*/hugepages/hugepages-2048kB/free_hugepages
5595
5366
the modify at qemu,
+int kvm_discard_range(struct kvm_discard_msg discard_msg)
+{
+ return kvm_vm_ioctl(kvm_state, KVM_DISCARD_RANGE, &discard_msg);
+}
static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq)
{
..................
+ discard_msg.in_addr = elem->in_addr[i];
+ discard_msg.iov_len = elem->in_sg[i].iov_len;
ram_block_discard_range(rb, ram_offset, size);
+ kvm_discard_range(discard_msg);
then, further test network bandwidth, performance seem ok.
Is there any hidden problem in this implementation?
And, is there plan to support pass-throughyour?
wei qi (2):
vfio: add mmap/munmap API for page hinting
KVM: add support for page hinting
arch/x86/kvm/mmu/mmu.c | 79 ++++++++++++++++++++
arch/x86/kvm/x86.c | 96 ++++++++++++++++++++++++
drivers/vfio/vfio.c | 109 ++++++++++++++++++++++++++++
drivers/vfio/vfio_iommu_type1.c | 157 +++++++++++++++++++++++++++++++++++++++-
include/linux/kvm_host.h | 41 +++++++++++
include/linux/vfio.h | 17 ++++-
include/uapi/linux/kvm.h | 7 ++
virt/kvm/vfio.c | 11 ---
8 files changed, 503 insertions(+), 14 deletions(-)
--
1.8.3.1
