Re: [PATCH v5 3/3] ppc: Enable 2nd DAWR support on p10

Cédric Le Goater
2021-04-12T13:10:38Z

On 4/12/21 1:44 PM, Ravi Bangoria wrote:
> As per the PAPR, bit 0 of byte 64 in pa-features property indicates
> availability of 2nd DAWR registers. i.e. If this bit is set, 2nd
> DAWR is present, otherwise not. Use KVM_CAP_PPC_DAWR1 capability to
> find whether kvm supports 2nd DAWR or not. If it's supported, allow
> user to set the pa-feature bit in guest DT using cap-dawr1 machine
> capability. Though, watchpoint on powerpc TCG guest is not supported
> and thus 2nd DAWR is not enabled for TCG mode.
>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
> Reviewed-by: Greg Kurz <groug@kaod.org>

Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks,

C.

> ---
> hw/ppc/spapr.c | 7 ++++++-
> hw/ppc/spapr_caps.c | 32 ++++++++++++++++++++++++++++++++
> include/hw/ppc/spapr.h | 6 +++++-
> target/ppc/cpu.h | 2 ++
> target/ppc/kvm.c | 12 ++++++++++++
> target/ppc/kvm_ppc.h | 12 ++++++++++++
> target/ppc/translate_init.c.inc | 15 +++++++++++++++
> 7 files changed, 84 insertions(+), 2 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 73a06df3b1..6317fad973 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -238,7 +238,7 @@ static void spapr_dt_pa_features(SpaprMachineState *spapr,
> 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, /* 48 - 53 */
> /* 54: DecFP, 56: DecI, 58: SHA */
> 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, /* 54 - 59 */
> - /* 60: NM atomic, 62: RNG */
> + /* 60: NM atomic, 62: RNG, 64: DAWR1 (ISA 3.1) */
> 0x80, 0x00, 0x80, 0x00, 0x00, 0x00, /* 60 - 65 */
> };
> uint8_t *pa_features = NULL;
> @@ -279,6 +279,9 @@ static void spapr_dt_pa_features(SpaprMachineState *spapr,
> * in pa-features. So hide it from them. */
> pa_features[40 + 2] &= ~0x80; /* Radix MMU */
> }
> + if (spapr_get_cap(spapr, SPAPR_CAP_DAWR1)) {
> + pa_features[66] |= 0x80;
> + }
>
> _FDT((fdt_setprop(fdt, offset, "ibm,pa-features", pa_features, pa_size)));
> }
> @@ -2003,6 +2006,7 @@ static const VMStateDescription vmstate_spapr = {
> &vmstate_spapr_cap_ccf_assist,
> &vmstate_spapr_cap_fwnmi,
> &vmstate_spapr_fwnmi,
> + &vmstate_spapr_cap_dawr1,
> NULL
> }
> };
> @@ -4542,6 +4546,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
> smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
> smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_ON;
> smc->default_caps.caps[SPAPR_CAP_FWNMI] = SPAPR_CAP_ON;
> + smc->default_caps.caps[SPAPR_CAP_DAWR1] = SPAPR_CAP_OFF;
> spapr_caps_add_properties(smc);
> smc->irq = &spapr_irq_dual;
> smc->dr_phb_enabled = true;
> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> index 9ea7ddd1e9..98a6b15f29 100644
> --- a/hw/ppc/spapr_caps.c
> +++ b/hw/ppc/spapr_caps.c
> @@ -523,6 +523,28 @@ static void cap_fwnmi_apply(SpaprMachineState *spapr, uint8_t val,
> }
> }
>
> +static void cap_dawr1_apply(SpaprMachineState *spapr, uint8_t val,
> + Error **errp)
> +{
> + ERRP_GUARD();
> + if (!val) {
> + return; /* Disable by default */
> + }
> +
> + if (tcg_enabled()) {
> + error_setg(errp, "DAWR1 not supported in TCG.");
> + error_append_hint(errp, "Try appending -machine cap-dawr1=off\n");
> + } else if (kvm_enabled()) {
> + if (!kvmppc_has_cap_dawr1()) {
> + error_setg(errp, "DAWR1 not supported by KVM.");
> + error_append_hint(errp, "Try appending -machine cap-dawr1=off\n");
> + } else if (kvmppc_set_cap_dawr1(val) < 0) {
> + error_setg(errp, "Error enabling cap-dawr1 with KVM.");
> + error_append_hint(errp, "Try appending -machine cap-dawr1=off\n");
> + }
> + }
> +}
> +
> SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> [SPAPR_CAP_HTM] = {
> .name = "htm",
> @@ -631,6 +653,15 @@ SpaprCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> .type = "bool",
> .apply = cap_fwnmi_apply,
> },
> + [SPAPR_CAP_DAWR1] = {
> + .name = "dawr1",
> + .description = "Allow 2nd Data Address Watchpoint Register (DAWR1)",
> + .index = SPAPR_CAP_DAWR1,
> + .get = spapr_cap_get_bool,
> + .set = spapr_cap_set_bool,
> + .type = "bool",
> + .apply = cap_dawr1_apply,
> + },
> };
>
> static SpaprCapabilities default_caps_with_cpu(SpaprMachineState *spapr,
> @@ -771,6 +802,7 @@ SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
> SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
> SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
> SPAPR_CAP_MIG_STATE(fwnmi, SPAPR_CAP_FWNMI);
> +SPAPR_CAP_MIG_STATE(dawr1, SPAPR_CAP_DAWR1);
>
> void spapr_caps_init(SpaprMachineState *spapr)
> {
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 5f90bb26d5..51202b7c90 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -74,8 +74,10 @@ typedef enum {
> #define SPAPR_CAP_CCF_ASSIST 0x09
> /* Implements PAPR FWNMI option */
> #define SPAPR_CAP_FWNMI 0x0A
> +/* DAWR1 */
> +#define SPAPR_CAP_DAWR1 0x0B
> /* Num Caps */
> -#define SPAPR_CAP_NUM (SPAPR_CAP_FWNMI + 1)
> +#define SPAPR_CAP_NUM (SPAPR_CAP_DAWR1 + 1)
>
> /*
> * Capability Values
> @@ -366,6 +368,7 @@ struct SpaprMachineState {
> #define H_SET_MODE_RESOURCE_SET_DAWR0 2
> #define H_SET_MODE_RESOURCE_ADDR_TRANS_MODE 3
> #define H_SET_MODE_RESOURCE_LE 4
> +#define H_SET_MODE_RESOURCE_SET_DAWR1 5
>
> /* Flags for H_SET_MODE_RESOURCE_LE */
> #define H_SET_MODE_ENDIAN_BIG 0
> @@ -921,6 +924,7 @@ extern const VMStateDescription vmstate_spapr_cap_nested_kvm_hv;
> extern const VMStateDescription vmstate_spapr_cap_large_decr;
> extern const VMStateDescription vmstate_spapr_cap_ccf_assist;
> extern const VMStateDescription vmstate_spapr_cap_fwnmi;
> +extern const VMStateDescription vmstate_spapr_cap_dawr1;
>
> static inline uint8_t spapr_get_cap(SpaprMachineState *spapr, int cap)
> {
> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> index cd02d65303..6a60416559 100644
> --- a/target/ppc/cpu.h
> +++ b/target/ppc/cpu.h
> @@ -1460,9 +1460,11 @@ typedef PowerPCCPU ArchCPU;
> #define SPR_PSPB (0x09F)
> #define SPR_DPDES (0x0B0)
> #define SPR_DAWR0 (0x0B4)
> +#define SPR_DAWR1 (0x0B5)
> #define SPR_RPR (0x0BA)
> #define SPR_CIABR (0x0BB)
> #define SPR_DAWRX0 (0x0BC)
> +#define SPR_DAWRX1 (0x0BD)
> #define SPR_HFSCR (0x0BE)
> #define SPR_VRSAVE (0x100)
> #define SPR_USPRG0 (0x100)
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index 104a308abb..fe3e8a13bb 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -89,6 +89,7 @@ static int cap_ppc_count_cache_flush_assist;
> static int cap_ppc_nested_kvm_hv;
> static int cap_large_decr;
> static int cap_fwnmi;
> +static int cap_dawr1;
>
> static uint32_t debug_inst_opcode;
>
> @@ -138,6 +139,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
> cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
> cap_large_decr = kvmppc_get_dec_bits();
> cap_fwnmi = kvm_vm_check_extension(s, KVM_CAP_PPC_FWNMI);
> + cap_dawr1 = kvm_vm_check_extension(s, KVM_CAP_PPC_DAWR1);
> /*
> * Note: setting it to false because there is not such capability
> * in KVM at this moment.
> @@ -2091,6 +2093,16 @@ int kvmppc_set_fwnmi(PowerPCCPU *cpu)
> return kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
> }
>
> +bool kvmppc_has_cap_dawr1(void)
> +{
> + return !!cap_dawr1;
> +}
> +
> +int kvmppc_set_cap_dawr1(int enable)
> +{
> + return kvm_vm_enable_cap(kvm_state, KVM_CAP_PPC_DAWR1, 0, enable);
> +}
> +
> int kvmppc_smt_threads(void)
> {
> return cap_ppc_smt ? cap_ppc_smt : 1;
> diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
> index 989f61ace0..47248fbbfd 100644
> --- a/target/ppc/kvm_ppc.h
> +++ b/target/ppc/kvm_ppc.h
> @@ -63,6 +63,8 @@ bool kvmppc_has_cap_htm(void);
> bool kvmppc_has_cap_mmu_radix(void);
> bool kvmppc_has_cap_mmu_hash_v3(void);
> bool kvmppc_has_cap_xive(void);
> +bool kvmppc_has_cap_dawr1(void);
> +int kvmppc_set_cap_dawr1(int enable);
> int kvmppc_get_cap_safe_cache(void);
> int kvmppc_get_cap_safe_bounds_check(void);
> int kvmppc_get_cap_safe_indirect_branch(void);
> @@ -341,6 +343,16 @@ static inline bool kvmppc_has_cap_xive(void)
> return false;
> }
>
> +static inline bool kvmppc_has_cap_dawr1(void)
> +{
> + return false;
> +}
> +
> +static inline int kvmppc_set_cap_dawr1(int enable)
> +{
> + abort();
> +}
> +
> static inline int kvmppc_get_cap_safe_cache(void)
> {
> return 0;
> diff --git a/target/ppc/translate_init.c.inc b/target/ppc/translate_init.c.inc
> index 879e6df217..8b76e191f1 100644
> --- a/target/ppc/translate_init.c.inc
> +++ b/target/ppc/translate_init.c.inc
> @@ -7765,6 +7765,20 @@ static void gen_spr_book3s_207_dbg(CPUPPCState *env)
> KVM_REG_PPC_CIABR, 0x00000000);
> }
>
> +static void gen_spr_book3s_310_dbg(CPUPPCState *env)
> +{
> + spr_register_kvm_hv(env, SPR_DAWR1, "DAWR1",
> + SPR_NOACCESS, SPR_NOACCESS,
> + SPR_NOACCESS, SPR_NOACCESS,
> + &spr_read_generic, &spr_write_generic,
> + KVM_REG_PPC_DAWR1, 0x00000000);
> + spr_register_kvm_hv(env, SPR_DAWRX1, "DAWRX1",
> + SPR_NOACCESS, SPR_NOACCESS,
> + SPR_NOACCESS, SPR_NOACCESS,
> + &spr_read_generic, &spr_write_generic,
> + KVM_REG_PPC_DAWRX1, 0x00000000);
> +}
> +
> static void gen_spr_970_dbg(CPUPPCState *env)
> {
> /* Breakpoints */
> @@ -9142,6 +9156,7 @@ static void init_proc_POWER10(CPUPPCState *env)
> /* Common Registers */
> init_proc_book3s_common(env);
> gen_spr_book3s_207_dbg(env);
> + gen_spr_book3s_310_dbg(env);
>
> /* POWER8 Specific Registers */
> gen_spr_book3s_ids(env);
>