diff mbox series

[v4,26/66] KVM: arm64: nv: Respect the virtual HCR_EL2.NV1 bit setting

Message ID 20210510165920.1913477-27-maz@kernel.org (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: ARMv8.3/8.4 Nested Virtualization support | expand

Commit Message

Marc Zyngier May 10, 2021, 4:58 p.m. UTC
From: Jintack Lim <jintack@cs.columbia.edu>

Forward ELR_EL1, SPSR_EL1 and VBAR_EL1 traps to the virtual EL2 if the
virtual HCR_EL2.NV bit is set.

This is for recursive nested virtualization.

Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_arm.h |  1 +
 arch/arm64/kvm/sys_regs.c        | 28 +++++++++++++++++++++++++++-
 2 files changed, 28 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index a85d7ea646cd..c2ab4e1802cf 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -14,6 +14,7 @@ 
 /* Hyp Configuration Register (HCR) bits */
 #define HCR_ATA		(UL(1) << 56)
 #define HCR_FWB		(UL(1) << 46)
+#define HCR_NV1		(UL(1) << 43)
 #define HCR_NV		(UL(1) << 42)
 #define HCR_API		(UL(1) << 41)
 #define HCR_APK		(UL(1) << 40)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 35bdfa0cb1ff..a577cdbacc17 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -292,6 +292,22 @@  static bool access_rw(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+/* This function is to support the recursive nested virtualization */
+static bool forward_nv1_traps(struct kvm_vcpu *vcpu, struct sys_reg_params *p)
+{
+	return forward_traps(vcpu, HCR_NV1);
+}
+
+static bool access_vbar_el1(struct kvm_vcpu *vcpu,
+			    struct sys_reg_params *p,
+			    const struct sys_reg_desc *r)
+{
+	if (forward_nv1_traps(vcpu, p))
+		return false;
+
+	return access_rw(vcpu, p, r);
+}
+
 static bool access_sctlr_el2(struct kvm_vcpu *vcpu,
 			     struct sys_reg_params *p,
 			     const struct sys_reg_desc *r)
@@ -1606,6 +1622,7 @@  static bool access_sp_el1(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+
 static bool access_elr(struct kvm_vcpu *vcpu,
 		       struct sys_reg_params *p,
 		       const struct sys_reg_desc *r)
@@ -1613,6 +1630,9 @@  static bool access_elr(struct kvm_vcpu *vcpu,
 	if (el12_reg(p) && forward_nv_traps(vcpu))
 		return false;
 
+	if (!el12_reg(p) && forward_nv1_traps(vcpu, p))
+		return false;
+
 	if (p->is_write)
 		vcpu_write_sys_reg(vcpu, p->regval, ELR_EL1);
 	else
@@ -1628,6 +1648,9 @@  static bool access_spsr(struct kvm_vcpu *vcpu,
 	if (el12_reg(p) && forward_nv_traps(vcpu))
 		return false;
 
+	if (!el12_reg(p) && forward_nv1_traps(vcpu, p))
+		return false;
+
 	if (p->is_write)
 		__vcpu_sys_reg(vcpu, SPSR_EL1) = p->regval;
 	else
@@ -1643,6 +1666,9 @@  static bool access_spsr_el2(struct kvm_vcpu *vcpu,
 	if (el12_reg(p) && forward_nv_traps(vcpu))
 		return false;
 
+	if (!el12_reg(p) && forward_nv1_traps(vcpu, p))
+		return false;
+
 	if (p->is_write)
 		vcpu_write_sys_reg(vcpu, p->regval, SPSR_EL2);
 	else
@@ -1851,7 +1877,7 @@  static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_LORC_EL1), trap_loregion },
 	{ SYS_DESC(SYS_LORID_EL1), trap_loregion },
 
-	{ SYS_DESC(SYS_VBAR_EL1), access_rw, reset_val, VBAR_EL1, 0 },
+	{ SYS_DESC(SYS_VBAR_EL1), access_vbar_el1, reset_val, VBAR_EL1, 0 },
 	{ SYS_DESC(SYS_DISR_EL1), NULL, reset_val, DISR_EL1, 0 },
 
 	{ SYS_DESC(SYS_ICC_IAR0_EL1), write_to_read_only },