[PATCH v3 20/66] KVM: arm64: nv: Trap CPACR_EL1 access in virtual EL2

Marc Zyngier
2020-12-10T16:31:23Z

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/include/asm/kvm_arm.h | 2 +-
arch/arm64/kvm/hyp/vhe/switch.c | 3 +++
arch/arm64/kvm/sys_regs.c | 2 +-
3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 4cf745f79985..3bd29fd01d80 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -269,7 +269,7 @@
#define CPTR_EL2_TFP_SHIFT 10

/* Hyp Coprocessor Trap Register */
-#define CPTR_EL2_TCPAC (1 << 31)
+#define CPTR_EL2_TCPAC (1U << 31)
#define CPTR_EL2_TAM (1 << 30)
#define CPTR_EL2_TTA (1 << 20)
#define CPTR_EL2_TFP (1 << CPTR_EL2_TFP_SHIFT)
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 3d8a4402b52c..66358f8ec5ad 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -68,6 +68,9 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
__activate_traps_fpsimd32(vcpu);
}

+ if (vcpu_mode_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 5185f148f25e..4410d399f8e2 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1736,7 +1736,7 @@ 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 },

{ SYS_DESC(SYS_RGSR_EL1), undef_access },
{ SYS_DESC(SYS_GCR_EL1), undef_access },
--
2.29.2