[PATCH 41/59] KVM: arm64: nv: Introduce sys_reg_desc.forward_trap

Marc Zyngier
2019-06-21T09:40:27Z

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

This introduces a function prototype to determine if we need to forward
system instruction traps to the virtual EL2. The implementation of
forward_trap functions for each system instruction will be added in
later patches.

Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kvm/sys_regs.c | 9 +++++++++
arch/arm64/kvm/sys_regs.h | 6 ++++++
2 files changed, 15 insertions(+)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index cc994ec3c121..8fbb04ddde11 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -36,6 +36,7 @@
#include <asm/kvm_host.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
+#include <asm/kvm_nested.h>
#include <asm/perf_event.h>
#include <asm/sysreg.h>

@@ -2532,6 +2533,14 @@ static void perform_access(struct kvm_vcpu *vcpu,
*/
BUG_ON(!r->access);

+ /*
+ * Forward this trap to the virtual EL2 if the guest hypervisor has
+ * configured to trap the current instruction.
+ */
+ if (nested_virt_in_use(vcpu) && r->forward_trap
+ && unlikely(r->forward_trap(vcpu)))
+ return;
+
/* Skip instruction if instructed so */
if (likely(r->access(vcpu, params, r)))
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index 2be99508dcb9..0702d6b401a1 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -65,6 +65,12 @@ struct sys_reg_desc {
int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr);

+ /*
+ * Forward the trap to the virtual EL2 if the guest hypervisor has
+ * configured to trap the current instruction.
+ */
+ bool (*forward_trap)(struct kvm_vcpu *vcpu);
+
/* Return mask of REG_* runtime visibility overrides */
unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd);
--
2.20.1