[PATCH 20/59] KVM: arm64: nv: Trap CPACR_EL1 access in virtual EL2

Marc Zyngier
2019-06-21T09:39:49Z

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 <marc.zyngier@arm.com>
---
arch/arm64/include/asm/kvm_arm.h | 3 ++-
arch/arm64/kvm/hyp/switch.c | 2 ++
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 b2e363ac624d..48e15af2bece 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -278,12 +278,13 @@
#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_TTA (1 << 20)
#define CPTR_EL2_TFP (1 << CPTR_EL2_TFP_SHIFT)
#define CPTR_EL2_TZ (1 << 8)
#define CPTR_EL2_RES1 0x000032ff /* known RES1 bits in CPTR_EL2 */
#define CPTR_EL2_DEFAULT CPTR_EL2_RES1
+#define CPTR_EL2_E2H_TCPAC (1U << 31)

/* Hyp Debug Configuration Register bits */
#define MDCR_EL2_TPMS (1 << 14)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 791b26570347..62359c7c3d6b 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -108,6 +108,8 @@ static void activate_traps_vhe(struct kvm_vcpu *vcpu)
val &= ~CPACR_EL1_FPEN;
__activate_traps_fpsimd32(vcpu);
}
+ if (vcpu_mode_el2(vcpu) && !vcpu_el2_e2h_is_set(vcpu))
+ val |= CPTR_EL2_E2H_TCPAC;

write_sysreg(val, cpacr_el1);

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 7fc87657382d..1d1312425cf2 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1773,7 +1773,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
ID_UNALLOCATED(7,7),

{ SYS_DESC(SYS_SCTLR_EL1), access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },
- { 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_ZCR_EL1), NULL, reset_val, ZCR_EL1, 0, .visibility = sve_visibility },
{ SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 },
{ SYS_DESC(SYS_TTBR1_EL1), access_vm_reg, reset_unknown, TTBR1_EL1 },
--
2.20.1