On Thu, 13 Mar 2025 at 07:16, Akihiko Odaki <akihiko.od...@daynix.com> wrote:
>
> PMCNTENCLR_EL0 and PMINTENCLR_EL1 clears written bits so we need an
> alternative raw write functions, which will be used to copy KVM kernel
> coprocessor state into userspace.
>
> Signed-off-by: Akihiko Odaki <akihiko.od...@daynix.com>
> ---
> target/arm/helper.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index f0ead22937bf..30883cd3a989 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -1907,7 +1907,8 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
> .fgt = FGT_PMCNTEN,
> .type = ARM_CP_ALIAS | ARM_CP_IO,
> .fieldoffset = offsetof(CPUARMState, cp15.c9_pmcnten),
> - .writefn = pmcntenclr_write },
> + .writefn = pmcntenclr_write,
> + .raw_writefn = raw_write },
> { .name = "PMOVSR", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 3,
> .access = PL0_RW, .type = ARM_CP_IO,
> .fieldoffset = offsetoflow32(CPUARMState, cp15.c9_pmovsr),
> @@ -2033,7 +2034,8 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
> .fgt = FGT_PMINTEN,
> .type = ARM_CP_ALIAS | ARM_CP_IO | ARM_CP_NO_RAW,
> .fieldoffset = offsetof(CPUARMState, cp15.c9_pminten),
> - .writefn = pmintenclr_write },
> + .writefn = pmintenclr_write,
> + .raw_writefn = raw_write },
> { .name = "CCSIDR", .state = ARM_CP_STATE_BOTH,
> .opc0 = 3, .crn = 0, .crm = 0, .opc1 = 1, .opc2 = 0,
> .access = PL1_R,
Hmm, looking more closely at this, I think this second one should
not need a raw_writefn, because it's marked as ARM_CP_NO_RAW
(meaning nothing should try to do a raw write to it).
And the first one is marked ARM_CP_ALIAS, so I'm not
sure why we would be using it in KVM register sync:
add_cpreg_to_list() skips ARM_CP_ALIAS (and ARM_CP_NO_RAW)
registers when we construct the cpreg_tuples[] array that
defines which sysregs we sync to and from KVM.
(We should arguably be consistent about our usage of the
NO_RAW flag between the pmintenclr and pmcntenclr registers.)
thanks
-- PMM
