On 08/12/15 12:47, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
>
> Since the reset value of PMEVCNTRn or PMCCNTR is UNKNOWN, use
> reset_unknown for its reset handler. Add access handler which emulates
> writing and reading PMEVCNTRn or PMCCNTR register. When reading
> PMEVCNTRn or PMCCNTR, call perf_event_read_value to get the count value
> of the perf event.
>
> Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
> ---
> arch/arm64/kvm/sys_regs.c | 107 +++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 105 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index c116a1b..f7a73b5 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -525,6 +525,12 @@ static bool access_pmu_regs(struct kvm_vcpu *vcpu,
>
> if (p->is_write) {
> switch (r->reg) {
> + case PMEVCNTR0_EL0 ... PMCCNTR_EL0: {
Same problem as previously mentioned.
> + val = kvm_pmu_get_counter_value(vcpu,
> + r->reg - PMEVCNTR0_EL0);
> + vcpu_sys_reg(vcpu, r->reg) += (s64)p->regval - val;
> + break;
> + }
> case PMEVTYPER0_EL0 ... PMCCFILTR_EL0: {
> val = r->reg - PMEVTYPER0_EL0;
> kvm_pmu_set_counter_event_type(vcpu, p->regval, val);
> @@ -548,6 +554,12 @@ static bool access_pmu_regs(struct kvm_vcpu *vcpu,
> }
> } else {
> switch (r->reg) {
> + case PMEVCNTR0_EL0 ... PMCCNTR_EL0: {
> + val = kvm_pmu_get_counter_value(vcpu,
> + r->reg - PMEVCNTR0_EL0);
> + p->regval = val;
> + break;
> + }
> case PMCR_EL0: {
> /* PMCR.P & PMCR.C are RAZ */
> val = vcpu_sys_reg(vcpu, r->reg)
> @@ -579,6 +591,13 @@ static bool access_pmu_regs(struct kvm_vcpu *vcpu,
> { Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b111), \
> trap_wcr, reset_wcr, n, 0, get_wcr, set_wcr }
>
> +/* Macro to expand the PMEVCNTRn_EL0 register */
> +#define PMU_PMEVCNTR_EL0(n) \
> + /* PMEVCNTRn_EL0 */ \
> + { Op0(0b11), Op1(0b011), CRn(0b1110), \
> + CRm((0b1000 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)), \
> + access_pmu_regs, reset_unknown, (PMEVCNTR0_EL0 + n), }
> +
> /* Macro to expand the PMEVTYPERn_EL0 register */
> #define PMU_PMEVTYPER_EL0(n) \
> /* PMEVTYPERn_EL0 */ \
> @@ -779,7 +798,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
> access_pmu_regs, reset_pmceid, PMCEID1_EL0 },
> /* PMCCNTR_EL0 */
> { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b000),
> - trap_raz_wi },
> + access_pmu_regs, reset_unknown, PMCCNTR_EL0 },
> /* PMXEVTYPER_EL0 */
> { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b001),
> access_pmu_pmxevtyper },
> @@ -800,6 +819,38 @@ static const struct sys_reg_desc sys_reg_descs[] = {
> { Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b011),
> NULL, reset_unknown, TPIDRRO_EL0 },
>
> + /* PMEVCNTRn_EL0 */
> + PMU_PMEVCNTR_EL0(0),
> + PMU_PMEVCNTR_EL0(1),
> + PMU_PMEVCNTR_EL0(2),
> + PMU_PMEVCNTR_EL0(3),
> + PMU_PMEVCNTR_EL0(4),
> + PMU_PMEVCNTR_EL0(5),
> + PMU_PMEVCNTR_EL0(6),
> + PMU_PMEVCNTR_EL0(7),
> + PMU_PMEVCNTR_EL0(8),
> + PMU_PMEVCNTR_EL0(9),
> + PMU_PMEVCNTR_EL0(10),
> + PMU_PMEVCNTR_EL0(11),
> + PMU_PMEVCNTR_EL0(12),
> + PMU_PMEVCNTR_EL0(13),
> + PMU_PMEVCNTR_EL0(14),
> + PMU_PMEVCNTR_EL0(15),
> + PMU_PMEVCNTR_EL0(16),
> + PMU_PMEVCNTR_EL0(17),
> + PMU_PMEVCNTR_EL0(18),
> + PMU_PMEVCNTR_EL0(19),
> + PMU_PMEVCNTR_EL0(20),
> + PMU_PMEVCNTR_EL0(21),
> + PMU_PMEVCNTR_EL0(22),
> + PMU_PMEVCNTR_EL0(23),
> + PMU_PMEVCNTR_EL0(24),
> + PMU_PMEVCNTR_EL0(25),
> + PMU_PMEVCNTR_EL0(26),
> + PMU_PMEVCNTR_EL0(27),
> + PMU_PMEVCNTR_EL0(28),
> + PMU_PMEVCNTR_EL0(29),
> + PMU_PMEVCNTR_EL0(30),
> /* PMEVTYPERn_EL0 */
> PMU_PMEVTYPER_EL0(0),
> PMU_PMEVTYPER_EL0(1),
> @@ -1034,6 +1085,12 @@ static bool access_pmu_cp15_regs(struct kvm_vcpu *vcpu,
>
> if (p->is_write) {
> switch (r->reg) {
> + case c14_PMEVCNTR0 ... c9_PMCCNTR: {
> + val = kvm_pmu_get_counter_value(vcpu,
> + r->reg - c14_PMEVCNTR0);
> + vcpu_cp15(vcpu, r->reg) += (s64)p->regval - val;
OK, we do have an interesting problem here. On 32bit, the cycle counter
can be accessed both as a 32bit or a 64bit register (ARMv8 ARM G6.4.2).
Here, you're happily truncating it, without paying attention to the size
of the access.
Please have a look at the way we handle c2_TTBR0, that will give you an
idea of how to deal with it.
> + break;
> + }
> case c14_PMEVTYPER0 ... c14_PMCCFILTR: {
> val = r->reg - c14_PMEVTYPER0;
> kvm_pmu_set_counter_event_type(vcpu, p->regval, val);
> @@ -1057,6 +1114,12 @@ static bool access_pmu_cp15_regs(struct kvm_vcpu *vcpu,
> }
> } else {
> switch (r->reg) {
> + case c14_PMEVCNTR0 ... c9_PMCCNTR: {
> + val = kvm_pmu_get_counter_value(vcpu,
> + r->reg - c14_PMEVCNTR0);
> + p->regval = val;
> + break;
> + }
Same here.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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