From: Anup Patel Date: Fri, 26 Nov 2021 11:35:51 +0000 (+0530) Subject: RISC-V: KVM: Add VM capability to allow userspace get GPA bits X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a457fd5660efa9cf960d2461156a1025bfdb13fa;p=linux.git RISC-V: KVM: Add VM capability to allow userspace get GPA bits The number of GPA bits supported for a RISC-V Guest/VM is based on the MMU mode used by the G-stage translation. The KVM RISC-V will detect and use the best possible MMU mode for the G-stage in kvm_arch_init(). We add a generic VM capability KVM_CAP_VM_GPA_BITS which can be used by the KVM userspace to get the number of GPA (guest physical address) bits supported for a Guest/VM. Signed-off-by: Anup Patel Reviewed-and-tested-by: Atish Patra --- diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h index 52e19888ce433..99ef6a1206177 100644 --- a/arch/riscv/include/asm/kvm_host.h +++ b/arch/riscv/include/asm/kvm_host.h @@ -218,6 +218,7 @@ void kvm_riscv_stage2_free_pgd(struct kvm *kvm); void kvm_riscv_stage2_update_hgatp(struct kvm_vcpu *vcpu); void kvm_riscv_stage2_mode_detect(void); unsigned long kvm_riscv_stage2_mode(void); +int kvm_riscv_stage2_gpa_bits(void); void kvm_riscv_stage2_vmid_detect(void); unsigned long kvm_riscv_stage2_vmid_bits(void); diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index 5f2736c2e773e..9af67dbdc66af 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -769,3 +769,8 @@ unsigned long kvm_riscv_stage2_mode(void) { return stage2_mode >> HGATP_MODE_SHIFT; } + +int kvm_riscv_stage2_gpa_bits(void) +{ + return stage2_gpa_bits; +} diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c index 7619691d89530..c768f75279ef6 100644 --- a/arch/riscv/kvm/vm.c +++ b/arch/riscv/kvm/vm.c @@ -74,6 +74,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_NR_MEMSLOTS: r = KVM_USER_MEM_SLOTS; break; + case KVM_CAP_VM_GPA_BITS: + r = kvm_riscv_stage2_gpa_bits(); + break; default: r = 0; break; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 1daa45268de26..469f05d69c8d1 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1131,6 +1131,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204 #define KVM_CAP_ARM_MTE 205 #define KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM 206 +#define KVM_CAP_VM_GPA_BITS 207 #ifdef KVM_CAP_IRQ_ROUTING