On Mon, Dec 18, 2023 at 10:54 PM Daniel Henrique Barboza
<dbarboza@ventanamicro.com> wrote:
>
> QEMU already implements zicbom (Cache Block Management Operations) and
> zicboz (Cache Block Zero Operations). Commit 59cb29d6a5 ("target/riscv:
> add Zicbop cbo.prefetch{i, r, m} placeholder") added placeholders for
> what would be the instructions for zicbop (Cache Block Prefetch
> Operations), which are now no-ops.
>
> The RVA22U64 profile mandates zicbop, which means that applications that
> run with this profile might expect zicbop to be present in the riscv,isa
> DT and might behave badly if it's absent.
>
> Adding zicbop as an extension will make our future RVA22U64
> implementation more in line with what userspace expects and, if/when
> cache block prefetch operations became relevant to QEMU, we already have
> the extension flag to turn then on/off as needed.
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
> ---
> hw/riscv/virt.c | 5 +++++
> target/riscv/cpu.c | 3 +++
> target/riscv/cpu_cfg.h | 2 ++
> 3 files changed, 10 insertions(+)
>
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index d2eac24156..da650865e5 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -273,6 +273,11 @@ static void create_fdt_socket_cpus(RISCVVirtState *s, int socket,
> cpu_ptr->cfg.cboz_blocksize);
> }
>
> + if (cpu_ptr->cfg.ext_zicbop) {
> + qemu_fdt_setprop_cell(ms->fdt, cpu_name, "riscv,cbop-block-size",
> + cpu_ptr->cfg.cbop_blocksize);
> + }
> +
> qemu_fdt_setprop_string(ms->fdt, cpu_name, "compatible", "riscv");
> qemu_fdt_setprop_string(ms->fdt, cpu_name, "status", "okay");
> qemu_fdt_setprop_cell(ms->fdt, cpu_name, "reg",
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 34102f6869..86e3514cc8 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -78,6 +78,7 @@ const uint32_t misa_bits[] = {RVI, RVE, RVM, RVA, RVF, RVD, RVV,
> */
> const RISCVIsaExtData isa_edata_arr[] = {
> ISA_EXT_DATA_ENTRY(zicbom, PRIV_VERSION_1_12_0, ext_zicbom),
> + ISA_EXT_DATA_ENTRY(zicbop, PRIV_VERSION_1_12_0, ext_zicbop),
> ISA_EXT_DATA_ENTRY(zicboz, PRIV_VERSION_1_12_0, ext_zicboz),
> ISA_EXT_DATA_ENTRY(zicond, PRIV_VERSION_1_12_0, ext_zicond),
> ISA_EXT_DATA_ENTRY(zicntr, PRIV_VERSION_1_12_0, ext_zicntr),
> @@ -1376,6 +1377,7 @@ const RISCVCPUMultiExtConfig riscv_cpu_extensions[] = {
> MULTI_EXT_CFG_BOOL("zhinxmin", ext_zhinxmin, false),
>
> MULTI_EXT_CFG_BOOL("zicbom", ext_zicbom, true),
> + MULTI_EXT_CFG_BOOL("zicbop", ext_zicbop, true),
> MULTI_EXT_CFG_BOOL("zicboz", ext_zicboz, true),
>
> MULTI_EXT_CFG_BOOL("zmmul", ext_zmmul, false),
> @@ -1510,6 +1512,7 @@ Property riscv_cpu_options[] = {
> DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
>
> DEFINE_PROP_UINT16("cbom_blocksize", RISCVCPU, cfg.cbom_blocksize, 64),
> + DEFINE_PROP_UINT16("cbop_blocksize", RISCVCPU, cfg.cbop_blocksize, 64),
> DEFINE_PROP_UINT16("cboz_blocksize", RISCVCPU, cfg.cboz_blocksize, 64),
>
> DEFINE_PROP_END_OF_LIST(),
> diff --git a/target/riscv/cpu_cfg.h b/target/riscv/cpu_cfg.h
> index f4605fb190..bd2ff87cc8 100644
> --- a/target/riscv/cpu_cfg.h
> +++ b/target/riscv/cpu_cfg.h
> @@ -65,6 +65,7 @@ struct RISCVCPUConfig {
> bool ext_zicntr;
> bool ext_zicsr;
> bool ext_zicbom;
> + bool ext_zicbop;
> bool ext_zicboz;
> bool ext_zicond;
> bool ext_zihintntl;
> @@ -142,6 +143,7 @@ struct RISCVCPUConfig {
> uint16_t vlen;
> uint16_t elen;
> uint16_t cbom_blocksize;
> + uint16_t cbop_blocksize;
> uint16_t cboz_blocksize;
> bool mmu;
> bool pmp;
> --
> 2.43.0
>
>