From 197bd237b67268651ac544e8fedbe1fd275d41e0 Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Tue, 5 Dec 2023 14:45:07 -0300 Subject: RISC-V: KVM: set 'vlenb' in kvm_riscv_vcpu_alloc_vector_context() 'vlenb', added to riscv_v_ext_state by commit c35f3aa34509 ("RISC-V: vector: export VLENB csr in __sc_riscv_v_state"), isn't being initialized in guest_context. If we export 'vlenb' as a KVM CSR, something we want to do in the next patch, it'll always return 0. Set 'vlenb' to riscv_v_size/32. Signed-off-by: Daniel Henrique Barboza Reviewed-by: Anup Patel Signed-off-by: Anup Patel --- arch/riscv/kvm/vcpu_vector.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/riscv/kvm/vcpu_vector.c') diff --git a/arch/riscv/kvm/vcpu_vector.c b/arch/riscv/kvm/vcpu_vector.c index b339a2682f25..530e49c588d6 100644 --- a/arch/riscv/kvm/vcpu_vector.c +++ b/arch/riscv/kvm/vcpu_vector.c @@ -76,6 +76,7 @@ int kvm_riscv_vcpu_alloc_vector_context(struct kvm_vcpu *vcpu, cntx->vector.datap = kmalloc(riscv_v_vsize, GFP_KERNEL); if (!cntx->vector.datap) return -ENOMEM; + cntx->vector.vlenb = riscv_v_vsize / 32; vcpu->arch.host_context.vector.datap = kzalloc(riscv_v_vsize, GFP_KERNEL); if (!vcpu->arch.host_context.vector.datap) -- cgit v1.2.3 From 2fa290372dfe7dd248b1c16f943f273a3e674f22 Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Tue, 5 Dec 2023 14:45:08 -0300 Subject: RISC-V: KVM: add 'vlenb' Vector CSR Userspace requires 'vlenb' to be able to encode it in reg ID. Otherwise it is not possible to retrieve any vector reg since we're returning EINVAL if reg_size isn't vlenb (see kvm_riscv_vcpu_vreg_addr()). Signed-off-by: Daniel Henrique Barboza Reviewed-by: Anup Patel Signed-off-by: Anup Patel --- arch/riscv/kvm/vcpu_vector.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'arch/riscv/kvm/vcpu_vector.c') diff --git a/arch/riscv/kvm/vcpu_vector.c b/arch/riscv/kvm/vcpu_vector.c index 530e49c588d6..d92d1348045c 100644 --- a/arch/riscv/kvm/vcpu_vector.c +++ b/arch/riscv/kvm/vcpu_vector.c @@ -116,6 +116,9 @@ static int kvm_riscv_vcpu_vreg_addr(struct kvm_vcpu *vcpu, case KVM_REG_RISCV_VECTOR_CSR_REG(vcsr): *reg_addr = &cntx->vector.vcsr; break; + case KVM_REG_RISCV_VECTOR_CSR_REG(vlenb): + *reg_addr = &cntx->vector.vlenb; + break; case KVM_REG_RISCV_VECTOR_CSR_REG(datap): default: return -ENOENT; @@ -174,6 +177,18 @@ int kvm_riscv_vcpu_set_reg_vector(struct kvm_vcpu *vcpu, if (!riscv_isa_extension_available(isa, v)) return -ENOENT; + if (reg_num == KVM_REG_RISCV_VECTOR_CSR_REG(vlenb)) { + struct kvm_cpu_context *cntx = &vcpu->arch.guest_context; + unsigned long reg_val; + + if (copy_from_user(®_val, uaddr, reg_size)) + return -EFAULT; + if (reg_val != cntx->vector.vlenb) + return -EINVAL; + + return 0; + } + rc = kvm_riscv_vcpu_vreg_addr(vcpu, reg_num, reg_size, ®_addr); if (rc) return rc; -- cgit v1.2.3