Hi Marc,
在 2023/7/13 星期四 14:56, Marc Zyngier 写道:
On Thu, 13 Jul 2023 03:35:39 +0100,
"chenxiang (M)" <chenxiang66@xxxxxxxxxxxxx> wrote:
Hi Marc,
在 2023/7/12 星期三 16:36, Marc Zyngier 写道:
On Wed, 12 Jul 2023 08:55:05 +0100,
chenxiang <chenxiang66@xxxxxxxxxxxxx> wrote:
From: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>
For those PMU system registers defined in sys_reg_descs[], use macro
PMU_SYS_REG() / PMU_PMEVCNTR_EL0 / PMU_PMEVTYPER_EL0 to define them, and
later two macros call macro PMU_SYS_REG() actually.
Currently the input parameter of PMU_SYS_REG() is other macro which is
calculation formula of the value of system registers, so for example, if
we want to "SYS_PMINTENSET_EL1" as the name of sys register, actually
the name will be as following:
(((3) << 19) | ((0) << 16) | ((9) << 12) | ((14) << 8) | ((1) << 5))
To fix the issue, use the name as a input parameter of PMU_SYS_REG like
MTE_REG or EL2_REG.
Why is the name relevant? Is this related to tracing?
I think It is not related to tracing. I find the issue when i want to
know which system reigsters are set
when on live migration and printk the name of sys_reg_desc in function
kvm_sys_reg_set_user,
find the name of some registers are abnormal as followings:
[ 227.145540] kvm_sys_reg_set_user 3427:SYS_FAR_EL1
[ 227.158057] kvm_sys_reg_set_user 3427:SYS_PAR_EL1
[ 227.170574] kvm_sys_reg_set_user 3427:(((3) << 19) | ((0) << 16) |
((9) << 12) | ((14) << 8) | ((1) << 5))
[ 227.188037] kvm_sys_reg_set_user 3427:(((3) << 19) | ((0) << 16) |
((9) << 12) | ((14) << 8) | ((2) << 5))
[ 227.205511] kvm_sys_reg_set_user 3427:SYS_MAIR_EL1
[ 227.218117] kvm_sys_reg_set_user 3427:SYS_PIRE0_EL1
So what is this if not some form of tracing?
Ah, i was misunderstood your question. I thought you aksed whether it is
related to kernel tracing
(which is already existed in kernel) such as tracepoint or debugfs.
I agree that it would be good to fix it, at least because the register
name is smaller than the encoding, but the commit message should at
least mention what this is used for.
Ok, i will modify commit message in next version.
Thanks,
M.
