From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Jones Date: Thu, 9 Feb 2023 16:26:27 +0100 Subject: [PATCH v4 7/8] RISC-V: KVM: Provide UAPI for Zicboz block size In-Reply-To: <20230209152628.129914-1-ajones@ventanamicro.com> References: <20230209152628.129914-1-ajones@ventanamicro.com> Message-ID: <20230209152628.129914-8-ajones@ventanamicro.com> List-Id: To: kvm-riscv@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit We're about to allow guests to use the Zicboz extension. KVM userspace needs to know the cache block size in order to properly advertise it to the guest. Provide a virtual config register for userspace to get it with the GET_ONE_REG API, but setting it cannot be supported, so disallow SET_ONE_REG. Signed-off-by: Andrew Jones Reviewed-by: Conor Dooley Reviewed-by: Anup Patel --- arch/riscv/include/uapi/asm/kvm.h | 1 + arch/riscv/kvm/vcpu.c | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h index 92af6f3f057c..c1a1bb0fa91c 100644 --- a/arch/riscv/include/uapi/asm/kvm.h +++ b/arch/riscv/include/uapi/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 */ diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 7c08567097f0..e5126cefbc87 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -276,6 +276,11 @@ static int kvm_riscv_vcpu_get_reg_config(struct kvm_vcpu *vcpu, return -EINVAL; reg_val = riscv_cbom_block_size; break; + case KVM_REG_RISCV_CONFIG_REG(zicboz_block_size): + if (!riscv_isa_extension_available(vcpu->arch.isa, ZICBOZ)) + return -EINVAL; + reg_val = riscv_cboz_block_size; + break; case KVM_REG_RISCV_CONFIG_REG(mvendorid): reg_val = vcpu->arch.mvendorid; break; @@ -347,6 +352,8 @@ static int kvm_riscv_vcpu_set_reg_config(struct kvm_vcpu *vcpu, break; case KVM_REG_RISCV_CONFIG_REG(zicbom_block_size): return -EOPNOTSUPP; + case KVM_REG_RISCV_CONFIG_REG(zicboz_block_size): + return -EOPNOTSUPP; case KVM_REG_RISCV_CONFIG_REG(mvendorid): if (!vcpu->arch.ran_atleast_once) vcpu->arch.mvendorid = reg_val; -- 2.39.1