From 665fd8862413f21cd924fc121eadcd32ea122c52 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Fri, 24 Feb 2023 17:26:30 +0100 Subject: [PATCH] RISC-V: KVM: Provide UAPI for Zicboz block size 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 Link: https://lore.kernel.org/r/20230224162631.405473-8-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt --- 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 7d010b0be54e..525d785ccba2 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -283,6 +283,11 @@ 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; @@ -354,6 +359,8 @@ 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; -- 2.34.1