[PATCH kvmtool 2/2] riscv: add zicboz support

[Andrew Jones]

On Tue, Apr 18, 2023 at 03:22:41PM +0100, Ben Dooks wrote:
> Like ZICBOM, the ZICBOZ extension requires passing extra information to
> the guest. Add the control to pass the information to the guest, get it
> from the kvm ioctl and pass into the guest via the device-tree info.
> 
> Signed-off-by: Ben Dooks <ben.dooks at codethink.co.uk>
> ---
>  riscv/fdt.c                         | 11 +++++++++++
>  riscv/include/asm/kvm.h             |  2 ++
>  riscv/include/kvm/kvm-config-arch.h |  3 +++
>  3 files changed, 16 insertions(+)

Hi Ben,

I have a patch almost identical to this one here

https://github.com/jones-drew/kvmtool/commit/f44010451e023b204bb1ef9767de20e0f20aca1c

The differences are that I don't add the header changes in this patch
(as they'll come with a proper header update after Linux patches get
merged), and I forgot to add the disable-zicboz, which you have.

I was planning on posting after the Linux patches get merged so
I could do the proper header update first.

Thanks,
drew


> 
> diff --git a/riscv/fdt.c b/riscv/fdt.c
> index 3cdb95c..fa6d153 100644
> --- a/riscv/fdt.c
> +++ b/riscv/fdt.c
> @@ -20,6 +20,7 @@ struct isa_ext_info isa_info_arr[] = {
>  	{"svinval", KVM_RISCV_ISA_EXT_SVINVAL},
>  	{"zihintpause", KVM_RISCV_ISA_EXT_ZIHINTPAUSE},
>  	{"zicbom", KVM_RISCV_ISA_EXT_ZICBOM},
> +	{"zicboz", KVM_RISCV_ISA_EXT_ZICBOZ},
>  };
>  
>  static void dump_fdt(const char *dtb_file, void *fdt)
> @@ -46,6 +47,7 @@ static void generate_cpu_nodes(void *fdt, struct kvm *kvm)
>  	const char *valid_isa_order = "IEMAFDQCLBJTPVNSUHKORWXYZG";
>  	int arr_sz = ARRAY_SIZE(isa_info_arr);
>  	unsigned long cbom_blksz = 0;
> +	unsigned long cboz_blksz = 0;
>  
>  	_FDT(fdt_begin_node(fdt, "cpus"));
>  	_FDT(fdt_property_cell(fdt, "#address-cells", 0x1));
> @@ -95,6 +97,13 @@ static void generate_cpu_nodes(void *fdt, struct kvm *kvm)
>  					die("KVM_GET_ONE_REG failed (config.zicbom_block_size)");
>  			}
>  
> +			if (isa_info_arr[i].ext_id == KVM_RISCV_ISA_EXT_ZICBOZ && !cboz_blksz) {
> +				reg.id = RISCV_CONFIG_REG(zicboz_block_size);
> +				reg.addr = (unsigned long)&cboz_blksz;
> +				if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, &reg) < 0)
> +					die("KVM_GET_ONE_REG failed (config.zicboz_block_size)");
> +			}
> +
>  			if ((strlen(isa_info_arr[i].name) + pos + 1) >= CPU_ISA_MAX_LEN) {
>  				pr_warning("Insufficient space to append ISA exension\n");
>  				break;
> @@ -116,6 +125,8 @@ static void generate_cpu_nodes(void *fdt, struct kvm *kvm)
>  		_FDT(fdt_property_string(fdt, "riscv,isa", cpu_isa));
>  		if (cbom_blksz)
>  			_FDT(fdt_property_cell(fdt, "riscv,cbom-block-size", cbom_blksz));
> +		if (cboz_blksz)
> +			_FDT(fdt_property_cell(fdt, "riscv,cboz-block-size", cboz_blksz));
>  		_FDT(fdt_property_cell(fdt, "reg", cpu));
>  		_FDT(fdt_property_string(fdt, "status", "okay"));
>  
> diff --git a/riscv/include/asm/kvm.h b/riscv/include/asm/kvm.h
> index 92af6f3..e44c1e9 100644
> --- a/riscv/include/asm/kvm.h
> +++ b/riscv/include/asm/kvm.h
> @@ -52,6 +52,7 @@ struct kvm_riscv_config {
>  	unsigned long mvendorid;
>  	unsigned long marchid;
>  	unsigned long mimpid;
> +	unsigned long zicboz_block_size;
>  };
>  
>  /* CORE registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
> @@ -105,6 +106,7 @@ enum KVM_RISCV_ISA_EXT_ID {
>  	KVM_RISCV_ISA_EXT_SVINVAL,
>  	KVM_RISCV_ISA_EXT_ZIHINTPAUSE,
>  	KVM_RISCV_ISA_EXT_ZICBOM,
> +	KVM_RISCV_ISA_EXT_ZICBOZ,
>  	KVM_RISCV_ISA_EXT_MAX,
>  };
>  
> diff --git a/riscv/include/kvm/kvm-config-arch.h b/riscv/include/kvm/kvm-config-arch.h
> index 188125c..46a774e 100644
> --- a/riscv/include/kvm/kvm-config-arch.h
> +++ b/riscv/include/kvm/kvm-config-arch.h
> @@ -24,6 +24,9 @@ struct kvm_config_arch {
>  	OPT_BOOLEAN('\0', "disable-zicbom",				\
>  		    &(cfg)->ext_disabled[KVM_RISCV_ISA_EXT_ZICBOM],	\
>  		    "Disable Zicbom Extension"),			\
> +	OPT_BOOLEAN('\0', "disable-zicboz",				\
> +		    &(cfg)->ext_disabled[KVM_RISCV_ISA_EXT_ZICBOZ],	\
> +		    "Disable Zicboz Extension"),			\
>  	OPT_BOOLEAN('\0', "disable-zihintpause",			\
>  		    &(cfg)->ext_disabled[KVM_RISCV_ISA_EXT_ZIHINTPAUSE],\
>  		    "Disable Zihintpause Extension"),
> -- 
> 2.39.2
>