linux_dsm_epyc7002/tools
Michael Ellerman c790c3d2b0 selftests/powerpc: Add a test of spectre_v2 mitigations
This test uses the PMU to count branch prediction hits/misses for a
known loop, and compare the result to the reported spectre v2
mitigation.

This gives us a way of sanity checking that the reported mitigation is
actually in effect.

Sample output for some cases, eg:

  Power9:
    sysfs reports: 'Vulnerable'
     PM_BR_PRED_CCACHE: result        368 running/enabled 5792777124
    PM_BR_MPRED_CCACHE: result        319 running/enabled 5792775546
     PM_BR_PRED_PCACHE: result 2147483281 running/enabled 5792773128
    PM_BR_MPRED_PCACHE: result  213604201 running/enabled 5792771640
    Miss percent 9 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.

    sysfs reports: 'Mitigation: Indirect branch serialisation (kernel only)'
     PM_BR_PRED_CCACHE: result        895 running/enabled 5780320920
    PM_BR_MPRED_CCACHE: result        822 running/enabled 5780312414
     PM_BR_PRED_PCACHE: result 2147482754 running/enabled 5780308836
    PM_BR_MPRED_PCACHE: result  213639731 running/enabled 5780307912
    Miss percent 9 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.

    sysfs reports: 'Mitigation: Indirect branch cache disabled'
     PM_BR_PRED_CCACHE: result 2147483649 running/enabled 20540186160
    PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 20540180056
     PM_BR_PRED_PCACHE: result          0 running/enabled 20540176090
    PM_BR_MPRED_PCACHE: result          0 running/enabled 20540174182
    Miss percent 100 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.

  Power8:
    sysfs reports: 'Vulnerable'
     PM_BR_PRED_CCACHE: result 2147483649 running/enabled 3505888142
    PM_BR_MPRED_CCACHE: result          9 running/enabled 3505882788
    Miss percent 0 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.

    sysfs reports: 'Mitigation: Indirect branch cache disabled'
     PM_BR_PRED_CCACHE: result 2147483649 running/enabled 16931421988
    PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 16931416478
    Miss percent 100 %
    OK - Measured branch prediction rates match reported spectre v2 mitigation.
    success: spectre_v2

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190520105520.22274-1-mpe@ellerman.id.au
2019-10-30 15:43:57 +11:00
..
accounting
arch tools arch x86: Sync asm/cpufeatures.h with the kernel sources 2019-09-20 15:00:49 -03:00
bpf
build
cgroup
debugging
firewire
firmware
gpio
hv - First round of vmbus hibernation support from Dexuan Cui. 2019-09-24 12:36:31 -07:00
iio
include Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-09-26 15:38:07 -07:00
io_uring
kvm/kvm_stat
laptop
leds
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-28 17:47:33 -07:00
memory-model
nfsd
objtool KVM: x86: Check kvm_rebooting in kvm_spurious_fault() 2019-09-25 15:23:33 +02:00
pci
pcmcia
perf perf unwind: Fix libunwind build failure on i386 systems 2019-09-26 21:59:38 +02:00
power platform-drivers-x86 for v5.4-2 2019-09-24 12:39:40 -07:00
scripts
spi
testing selftests/powerpc: Add a test of spectre_v2 mitigations 2019-10-30 15:43:57 +11:00
thermal/tmon
time
usb
virtio
vm
wmi
Makefile