[PATCH v6 20/64] KVM: arm64: nv: Trap CPACR_EL1 access in virtual EL2

Marc Zyngier
2022-01-28T12:20:25Z

From: Jintack Lim <jintack.lim@linaro.org>

For the same reason we trap virtual memory register accesses in virtual
EL2, we trap CPACR_EL1 access too; We allow the virtual EL2 mode to
access EL1 system register state instead of the virtual EL2 one.

Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/hyp/vhe/switch.c | 3 +++
arch/arm64/kvm/sys_regs.c | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 6ed9e4893a02..1e6a00e7bfb3 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -64,6 +64,9 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
__activate_traps_fpsimd32(vcpu);
}

+ if (vcpu_is_el2(vcpu) && !vcpu_el2_e2h_is_set(vcpu))
+ val |= CPTR_EL2_TCPAC;
+
write_sysreg(val, cpacr_el1);

write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el1);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 4f2bcc1e0c25..7f074a7f6eb3 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1819,7 +1819,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {

{ SYS_DESC(SYS_SCTLR_EL1), access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },
{ SYS_DESC(SYS_ACTLR_EL1), access_actlr, reset_actlr, ACTLR_EL1 },
- { SYS_DESC(SYS_CPACR_EL1), NULL, reset_val, CPACR_EL1, 0 },
+ { SYS_DESC(SYS_CPACR_EL1), access_rw, reset_val, CPACR_EL1, 0 },

MTE_REG(RGSR_EL1),
MTE_REG(GCR_EL1),