Hi Suravee!
Just in case (!), I've run your revert+update patch on kernel 5.11.0-13,
Ubuntu 21.04β running on an AMD FX-8350 (pre Zen and IOMMUv2). As with
the AMD Ryzen 2400G and 4700U, I'm finding no obvious issues.
$ sudo dmesg | grep IOMMU
[ 0.948890] pci 0000:00:00.2: AMD-Vi: Found IOMMU cap 0x40
[ 4.393773] AMD-Vi: AMD IOMMUv2 driver by Joerg Roedel <jroe...@suse.de>
[ 4.393776] AMD-Vi: AMD IOMMUv2 functionality not available on this
system
$ systool -m kvm_amd -v
Module = "kvm_amd"
Attributes:
coresize = "114688"
initsize = "0"
initstate = "live"
refcnt = "0"
srcversion = "4371BA17A41823101F90761"
taint = ""
uevent = <store method only>
Parameters:
avic = "0"
dump_invalid_vmcb = "N"
nested = "1"
npt = "1"
nrips = "1"
pause_filter_count_grow= "2"
pause_filter_count_max= "65535"
pause_filter_count_shrink= "0"
pause_filter_count = "3000"
pause_filter_thresh = "128"
sev_es = "0"
sev = "0"
vgif = "0"
vls = "0"
Sections:
$ compgen -G "/sys/kernel/iommu_groups/*/devices/*"
/sys/kernel/iommu_groups/9/devices/0000:00:14.2
/sys/kernel/iommu_groups/0/devices/0000:00:00.0
/sys/kernel/iommu_groups/10/devices/0000:00:14.3
/sys/kernel/iommu_groups/2/devices/0000:00:04.0
/sys/kernel/iommu_groups/12/devices/0000:00:14.5
/sys/kernel/iommu_groups/4/devices/0000:00:0d.0
/sys/kernel/iommu_groups/14/devices/0000:00:16.0
/sys/kernel/iommu_groups/14/devices/0000:00:16.2
/sys/kernel/iommu_groups/6/devices/0000:00:12.0
/sys/kernel/iommu_groups/6/devices/0000:00:12.2
/sys/kernel/iommu_groups/16/devices/0000:02:00.0
/sys/kernel/iommu_groups/8/devices/0000:00:14.0
/sys/kernel/iommu_groups/1/devices/0000:00:02.0
/sys/kernel/iommu_groups/11/devices/0000:00:14.4
/sys/kernel/iommu_groups/3/devices/0000:00:0b.0
/sys/kernel/iommu_groups/13/devices/0000:00:15.3
/sys/kernel/iommu_groups/13/devices/0000:00:15.0
/sys/kernel/iommu_groups/13/devices/0000:06:00.0
/sys/kernel/iommu_groups/13/devices/0000:00:15.2
/sys/kernel/iommu_groups/13/devices/0000:07:00.0
/sys/kernel/iommu_groups/13/devices/0000:08:00.0
/sys/kernel/iommu_groups/13/devices/0000:00:15.1
/sys/kernel/iommu_groups/13/devices/0000:09:00.0
/sys/kernel/iommu_groups/5/devices/0000:00:11.0
/sys/kernel/iommu_groups/15/devices/0000:01:00.1
/sys/kernel/iommu_groups/15/devices/0000:01:00.0
/sys/kernel/iommu_groups/7/devices/0000:00:13.0
/sys/kernel/iommu_groups/7/devices/0000:00:13.2
/sys/kernel/iommu_groups/17/devices/0000:04:00.0
$ sudo kvm-ok
INFO: /dev/kvm exists
KVM acceleration can be used
$ perf list | grep iommu
No amd_iommu events
Best regards and many thanks.
--
David Coe
