For the same reason we trap virtual memory register accesses in virtual
EL2, we need to trap SPSR_EL1, ELR_EL1 and VBAR_EL1 accesses. ARM v8.3
introduces the HCR_EL2.NV1 bit to be able to trap on those register
accesses in EL1. Do not set this bit until the whole nesting support is
complete.

Signed-off-by: Jintack Lim <[email protected]>
---
 arch/arm64/kvm/sys_regs.c | 41 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0f5d21b..19d6a6e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -898,6 +898,38 @@ static bool access_cntp_cval(struct kvm_vcpu *vcpu,
        return true;
 }
 
+static inline void access_rw(struct sys_reg_params *p, u64 *sysreg)
+{
+       if (!p->is_write)
+               p->regval = *sysreg;
+       else
+               *sysreg = p->regval;
+}
+
+static bool access_elr(struct kvm_vcpu *vcpu,
+               struct sys_reg_params *p,
+               const struct sys_reg_desc *r)
+{
+       access_rw(p, &vcpu->arch.ctxt.gp_regs.elr_el1);
+       return true;
+}
+
+static bool access_spsr(struct kvm_vcpu *vcpu,
+               struct sys_reg_params *p,
+               const struct sys_reg_desc *r)
+{
+       access_rw(p, &vcpu->arch.ctxt.gp_regs.spsr[KVM_SPSR_EL1]);
+       return true;
+}
+
+static bool access_vbar(struct kvm_vcpu *vcpu,
+               struct sys_reg_params *p,
+               const struct sys_reg_desc *r)
+{
+       access_rw(p, &vcpu_sys_reg(vcpu, r->reg));
+       return true;
+}
+
 static bool trap_el2_reg(struct kvm_vcpu *vcpu,
                         struct sys_reg_params *p,
                         const struct sys_reg_desc *r)
@@ -1013,6 +1045,13 @@ static bool trap_el2_reg(struct kvm_vcpu *vcpu,
        { Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b010),
          access_vm_reg, reset_val, TCR_EL1, 0 },
 
+       /* SPSR_EL1 */
+       { Op0(0b11), Op1(0b000), CRn(0b0100), CRm(0b0000), Op2(0b000),
+         access_spsr},
+       /* ELR_EL1 */
+       { Op0(0b11), Op1(0b000), CRn(0b0100), CRm(0b0000), Op2(0b001),
+         access_elr},
+
        /* AFSR0_EL1 */
        { Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0001), Op2(0b000),
          access_vm_reg, reset_unknown, AFSR0_EL1 },
@@ -1045,7 +1084,7 @@ static bool trap_el2_reg(struct kvm_vcpu *vcpu,
 
        /* VBAR_EL1 */
        { Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b0000), Op2(0b000),
-         NULL, reset_val, VBAR_EL1, 0 },
+         access_vbar, reset_val, VBAR_EL1, 0 },
 
        /* ICC_SGI1R_EL1 */
        { Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1011), Op2(0b101),
-- 
1.9.1


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