On Tue, Oct 14, 2025 at 6:24 PM Jay Chang <[email protected]> wrote: > > Previously, the PMP granularity in qemu always used a minimum > granularity of 4 bytes, this patch add pmp-granularity to allow > platforms to configure the value. > > A new CPU parameter pmp-granularity has been introduced to the QEMU > command line. For example: > > -cpu rv64, g=true, c=true, pmp=true, pmp-granularity=1024 > > If no specific value is provided, the default value is 4 bytes. > > Signed-off-by: Jay Chang <[email protected]> > Reviewed-by: Frank Chang <[email protected]> > Reviewed-by: Jim Shu <[email protected]>
Reviewed-by: Alistair Francis <[email protected]> Alistair > --- > target/riscv/cpu.c | 39 +++++++++++++++++++++++++++++++ > target/riscv/cpu.h | 1 + > target/riscv/cpu_cfg_fields.h.inc | 1 + > 3 files changed, 41 insertions(+) > > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c > index a877018ab0..73d4280d7c 100644 > --- a/target/riscv/cpu.c > +++ b/target/riscv/cpu.c > @@ -1121,6 +1121,7 @@ static void riscv_cpu_init(Object *obj) > cpu->cfg.cbop_blocksize = 64; > cpu->cfg.cboz_blocksize = 64; > cpu->cfg.pmp_regions = 16; > + cpu->cfg.pmp_granularity = MIN_RISCV_PMP_GRANULARITY; > cpu->env.vext_ver = VEXT_VERSION_1_00_0; > cpu->cfg.max_satp_mode = -1; > > @@ -1606,6 +1607,43 @@ static const PropertyInfo prop_num_pmp_regions = { > .set = prop_num_pmp_regions_set, > }; > > +static void prop_pmp_granularity_set(Object *obj, Visitor *v, const char > *name, > + void *opaque, Error **errp) > +{ > + RISCVCPU *cpu = RISCV_CPU(obj); > + uint32_t value; > + > + visit_type_uint32(v, name, &value, errp); > + > + if ((value < MIN_RISCV_PMP_GRANULARITY) && (value & (value - 1))) { > + error_setg(errp, "PMP granularity must be a power of 2 and at least > %d", > + MIN_RISCV_PMP_GRANULARITY); > + return; > + } > + > + if (cpu->cfg.pmp_granularity != value && riscv_cpu_is_vendor(obj)) { > + cpu_set_prop_err(cpu, name, errp); > + return; > + } > + > + cpu_option_add_user_setting(name, value); > + cpu->cfg.pmp_granularity = value; > +} > + > +static void prop_pmp_granularity_get(Object *obj, Visitor *v, const char > *name, > + void *opaque, Error **errp) > +{ > + uint32_t value = RISCV_CPU(obj)->cfg.pmp_granularity; > + > + visit_type_uint32(v, name, &value, errp); > +} > + > +static const PropertyInfo prop_pmp_granularity = { > + .description = "pmp-granularity", > + .get = prop_pmp_granularity_get, > + .set = prop_pmp_granularity_set, > +}; > + > static int priv_spec_from_str(const char *priv_spec_str) > { > int priv_version = -1; > @@ -2606,6 +2644,7 @@ static const Property riscv_cpu_properties[] = { > {.name = "mmu", .info = &prop_mmu}, > {.name = "pmp", .info = &prop_pmp}, > {.name = "num-pmp-regions", .info = &prop_num_pmp_regions}, > + {.name = "pmp-granularity", .info = &prop_pmp_granularity}, > > {.name = "priv_spec", .info = &prop_priv_spec}, > {.name = "vext_spec", .info = &prop_vext_spec}, > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h > index 2c2266415e..04711f93a2 100644 > --- a/target/riscv/cpu.h > +++ b/target/riscv/cpu.h > @@ -176,6 +176,7 @@ extern RISCVCPUImpliedExtsRule > *riscv_multi_ext_implied_rules[]; > > #define MAX_RISCV_PMPS (64) > #define OLD_MAX_RISCV_PMPS (16) > +#define MIN_RISCV_PMP_GRANULARITY 4 > > #if !defined(CONFIG_USER_ONLY) > #include "pmp.h" > diff --git a/target/riscv/cpu_cfg_fields.h.inc > b/target/riscv/cpu_cfg_fields.h.inc > index e2d116f0df..a154ecdc79 100644 > --- a/target/riscv/cpu_cfg_fields.h.inc > +++ b/target/riscv/cpu_cfg_fields.h.inc > @@ -166,6 +166,7 @@ TYPED_FIELD(uint16_t, cbom_blocksize, 0) > TYPED_FIELD(uint16_t, cbop_blocksize, 0) > TYPED_FIELD(uint16_t, cboz_blocksize, 0) > TYPED_FIELD(uint8_t, pmp_regions, 0) > +TYPED_FIELD(uint32_t, pmp_granularity, 0) > > TYPED_FIELD(int8_t, max_satp_mode, -1) > > -- > 2.48.1 > >
