diff mbox series

[5/8] KVM: arm64: Don't log IMP DEF sysreg traps

Message ID 20191212172824.11523-6-maz@kernel.org (mailing list archive)
State Mainlined
Commit 54ad68b7776043a77c9bf0a67d49cd9cb261a8e7
Headers show
Series [GIT,PULL] KVM/arm updates for 5.5-rc2 | expand

Commit Message

Marc Zyngier Dec. 12, 2019, 5:28 p.m. UTC 
From: Mark Rutland <mark.rutland@arm.com>

We don't intend to support IMPLEMENATION DEFINED system registers, but
have to trap them (and emulate them as UNDEFINED). These traps aren't
interesting to the system administrator or to the KVM developers, so
let's not bother logging when we do so.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191205180652.18671-3-mark.rutland@arm.com
---
 arch/arm64/kvm/sys_regs.c | 8 ++++++++
 1 file changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index e8bf08e09f78..bd2ac3796d8d 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2229,6 +2229,12 @@  int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
 				NULL, 0);
 }
 
+static bool is_imp_def_sys_reg(struct sys_reg_params *params)
+{
+	// See ARM DDI 0487E.a, section D12.3.2
+	return params->Op0 == 3 && (params->CRn & 0b1011) == 0b1011;
+}
+
 static int emulate_sys_reg(struct kvm_vcpu *vcpu,
 			   struct sys_reg_params *params)
 {
@@ -2244,6 +2250,8 @@  static int emulate_sys_reg(struct kvm_vcpu *vcpu,
 
 	if (likely(r)) {
 		perform_access(vcpu, params, r);
+	} else if (is_imp_def_sys_reg(params)) {
+		kvm_inject_undefined(vcpu);
 	} else {
 		print_sys_reg_msg(params,
 				  "Unsupported guest sys_reg access at: %lx [%08lx]\n",