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.

Anup Patel committed 4 years ago

Commit a457fd51 parent ef8949a4 files · +10 −0Browse files

Unified · Split

4 files

arch/riscv/include/asm/kvm_host.h +1 −0
arch/riscv/kvm/mmu.c +5 −0
arch/riscv/kvm/vm.c +3 −0
include/uapi/linux/kvm.h +1 −0

arch/riscv/include/asm/kvm_host.h+1−0

@@ -218,6 +218,7 @@ void kvm_riscv_stage2_free_pgd(struct kvm *kvm); · 217 unmodified lines
218	218	void kvm_riscv_stage2_update_hgatp(struct kvm_vcpu *vcpu);
219	219	void kvm_riscv_stage2_mode_detect(void);
220	220	unsigned long kvm_riscv_stage2_mode(void);
	221	+int kvm_riscv_stage2_gpa_bits(void);
221	222
222	223	void kvm_riscv_stage2_vmid_detect(void);
223	224	unsigned long kvm_riscv_stage2_vmid_bits(void);

arch/riscv/kvm/mmu.c+5−0

@@ -769,3 +769,8 @@ unsigned long kvm_riscv_stage2_mode(void) · 768 unmodified lines
769	769	{
770	770	return stage2_mode >> HGATP_MODE_SHIFT;
771	771	}
	772	+
	773	+int kvm_riscv_stage2_gpa_bits(void)
	774	+{
	775	+ return stage2_gpa_bits;
	776	+}

arch/riscv/kvm/vm.c+3−0

@@ -74,6 +74,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) · 73 unmodified lines
74	74	case KVM_CAP_NR_MEMSLOTS:
75	75	r = KVM_USER_MEM_SLOTS;
76	76	break;
	77	+ case KVM_CAP_VM_GPA_BITS:
	78	+ r = kvm_riscv_stage2_gpa_bits();
	79	+ break;
77	80	default:
78	81	r = 0;
79	82	break;

include/uapi/linux/kvm.h+1−0

@@ -1131,6 +1131,7 @@ struct kvm_ppc_resize_hpt { · 1130 unmodified lines
1131	1131	#define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204
1132	1132	#define KVM_CAP_ARM_MTE 205
1133	1133	#define KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM 206
	1134	+#define KVM_CAP_VM_GPA_BITS 207
1134	1135
1135	1136	#ifdef KVM_CAP_IRQ_ROUTING
1136	1137