On Tuesday, January 18, 2022 11:54 AM, Jim Mattson wrote:
On Fri, Dec 17, 2021 at 6:05 AM Wei Wang wei.w.wang@intel.com wrote:
The fixed counter 3 is used for the Topdown metrics, which hasn't been enabled for KVM guests. Userspace accessing to it will fail as it's not included in get_fixed_pmc(). This breaks KVM selftests on ICX+ machines, which have this counter.
To reproduce it on ICX+ machines, ./state_test reports: ==== Test Assertion Failure ==== lib/x86_64/processor.c:1078: r == nmsrs pid=4564 tid=4564 - Argument list too long 1 0x000000000040b1b9: vcpu_save_state at processor.c:1077 2 0x0000000000402478: main at state_test.c:209 (discriminator 6) 3 0x00007fbe21ed5f92: ?? ??:0 4 0x000000000040264d: _start at ??:? Unexpected result from KVM_GET_MSRS, r: 17 (failed MSR was 0x30c)
With this patch, it works well.
Signed-off-by: Wei Wang wei.w.wang@intel.com
Reviewed-and-tested-by: Jim Mattson jmattson@google.com
I believe this fixes commit 2e8cd7a3b828 ("kvm: x86: limit the maximum number of vPMU fixed counters to 3") from v5.9. Should this be cc'ed to stable?
Sounds good to me.
Thanks, Wei
On 1/18/22 06:04, Wang, Wei W wrote:
On Tuesday, January 18, 2022 11:54 AM, Jim Mattson wrote:
On Fri, Dec 17, 2021 at 6:05 AM Wei Wang wei.w.wang@intel.com wrote:
The fixed counter 3 is used for the Topdown metrics, which hasn't been enabled for KVM guests. Userspace accessing to it will fail as it's not included in get_fixed_pmc(). This breaks KVM selftests on ICX+ machines, which have this counter.
To reproduce it on ICX+ machines, ./state_test reports: ==== Test Assertion Failure ==== lib/x86_64/processor.c:1078: r == nmsrs pid=4564 tid=4564 - Argument list too long 1 0x000000000040b1b9: vcpu_save_state at processor.c:1077 2 0x0000000000402478: main at state_test.c:209 (discriminator 6) 3 0x00007fbe21ed5f92: ?? ??:0 4 0x000000000040264d: _start at ??:? Unexpected result from KVM_GET_MSRS, r: 17 (failed MSR was 0x30c)
With this patch, it works well.
Signed-off-by: Wei Wang wei.w.wang@intel.com
Reviewed-and-tested-by: Jim Mattson jmattson@google.com
I believe this fixes commit 2e8cd7a3b828 ("kvm: x86: limit the maximum number of vPMU fixed counters to 3") from v5.9. Should this be cc'ed to stable?
Sounds good to me.
Sent, thanks.
Paolo
linux-stable-mirror@lists.linaro.org
-
Paolo Bonzini -
Wang, Wei W