[09/14] KVM: arm64: Move NV-specific capping to idreg sanitisation

Commit Message

Marc Zyngier Feb. 15, 2025, 5:38 p.m. UTC

Instead of applying the NV idreg limits at run time, switch to
doing it at the same time as the reset of the VM initialisation.

This will make things much simpler once we introduce vcpu-driven
variants of NV.

Signed-off-by: Marc Zyngier <[e-mail]>
---
 arch/arm64/include/asm/kvm_nested.h |  1 +
 arch/arm64/kvm/nested.c             | 45 +----------------------------
 arch/arm64/kvm/sys_regs.c           |  3 ++
 3 files changed, 5 insertions(+), 44 deletions(-)

Patch

diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index 56c4bcd35e2e5..692f403c1896e 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -188,6 +188,7 @@  static inline bool kvm_supported_tlbi_s1e2_op(struct kvm_vcpu *vpcu, u32 instr)
 }
 
 int kvm_init_nv_sysregs(struct kvm_vcpu *vcpu);
+u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val);
 
 #ifdef CONFIG_ARM64_PTR_AUTH
 bool kvm_auth_eretax(struct kvm_vcpu *vcpu, u64 *elr);
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 2cc82e69ab523..96d1d300e79f9 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -804,7 +804,7 @@  void kvm_arch_flush_shadow_all(struct kvm *kvm)
  * This list should get updated as new features get added to the NV
  * support, and new extension to the architecture.
  */
-static u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
+u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 {
 	switch (reg) {
 	case SYS_ID_AA64ISAR0_EL1:
@@ -929,47 +929,6 @@  static u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 	return val;
 }
 
-static void limit_nv_id_regs(struct kvm *kvm)
-{
-	u64 val;
-
-	val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64ISAR0_EL1);
-	val = limit_nv_id_reg(kvm, SYS_ID_AA64ISAR0_EL1, val);
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64ISAR0_EL1, val);
-
-	val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64ISAR1_EL1);
-	val = limit_nv_id_reg(kvm, SYS_ID_AA64ISAR1_EL1, val);
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64ISAR1_EL1, val);
-
-	val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1);
-	val = limit_nv_id_reg(kvm, SYS_ID_AA64PFR0_EL1, val);
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, val);
-
-	val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR1_EL1);
-	val = limit_nv_id_reg(kvm, SYS_ID_AA64PFR1_EL1, val);
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR1_EL1, val);
-
-	val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR0_EL1);
-	val = limit_nv_id_reg(kvm, SYS_ID_AA64MMFR0_EL1, val);
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR0_EL1, val);
-
-	val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR1_EL1);
-	val = limit_nv_id_reg(kvm, SYS_ID_AA64MMFR1_EL1, val);
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR1_EL1, val);
-
-	val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR2_EL1);
-	val = limit_nv_id_reg(kvm, SYS_ID_AA64MMFR2_EL1, val);
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR2_EL1, val);
-
-	val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR4_EL1);
-	val = limit_nv_id_reg(kvm, SYS_ID_AA64MMFR4_EL1, val);
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR4_EL1, val);
-
-	val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1);
-	val = limit_nv_id_reg(kvm, SYS_ID_AA64DFR0_EL1, val);
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1, val);
-}
-
 u64 kvm_vcpu_apply_reg_masks(const struct kvm_vcpu *vcpu,
 			     enum vcpu_sysreg sr, u64 v)
 {
@@ -1014,8 +973,6 @@  int kvm_init_nv_sysregs(struct kvm_vcpu *vcpu)
 	if (!kvm->arch.sysreg_masks)
 		return -ENOMEM;
 
-	limit_nv_id_regs(kvm);
-
 	/* VTTBR_EL2 */
 	res0 = res1 = 0;
 	if (!kvm_has_feat_enum(kvm, ID_AA64MMFR1_EL1, VMIDBits, 16))
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 885cdef77d01e..c1e050a58fb2e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1638,6 +1638,9 @@  static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
 		break;
 	}
 
+	if (vcpu_has_nv(vcpu))
+		val = limit_nv_id_reg(vcpu->kvm, id, val);
+
 	return val;
 }