From: Marc Zyngier <marc.zyngier@arm.com>
Date: Fri, 9 Jun 2017 12:49:53 +0100
Subject: KVM: arm64: Enable GICv3 common sysreg trapping via command-line
Patch-mainline: v4.13-rc1
Git-commit: ff89511ef29b794d6a9c6b62f5ea76fc013cdae7
References: bsc#1077761
Now that we're able to safely handle common sysreg access, let's
give the user the opportunity to enable it by passing a specific
command-line option (vgic_v3.common_trap).
Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Acked-by: Alexander Graf <agraf@suse.de>
---
Documentation/admin-guide/kernel-parameters.txt | 4 ++++
include/linux/irqchip/arm-gic-v3.h | 1 +
virt/kvm/arm/vgic/vgic-v3.c | 11 ++++++++++-
3 files changed, 15 insertions(+), 1 deletion(-)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1846,6 +1846,10 @@
[KVM,ARM] Trap guest accesses to GICv3 group-1
system registers
+ kvm-arm.vgic_v3_common_trap=
+ [KVM,ARM] Trap guest accesses to GICv3 common
+ system registers
+
kvm-intel.ept= [KVM,Intel] Disable extended page tables
(virtualized MMU) support on capable Intel chips.
Default is 1 (enabled)
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -417,6 +417,7 @@
#define ICH_HCR_EN (1 << 0)
#define ICH_HCR_UIE (1 << 1)
+#define ICH_HCR_TC (1 << 10)
#define ICH_HCR_TALL0 (1 << 11)
#define ICH_HCR_TALL1 (1 << 12)
#define ICH_HCR_EOIcount_SHIFT 27
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -23,6 +23,7 @@
static bool group0_trap;
static bool group1_trap;
+static bool common_trap;
void vgic_v3_set_underflow(struct kvm_vcpu *vcpu)
{
@@ -265,6 +266,8 @@
vgic_v3->vgic_hcr |= ICH_HCR_TALL0;
if (group1_trap)
vgic_v3->vgic_hcr |= ICH_HCR_TALL1;
+ if (common_trap)
+ vgic_v3->vgic_hcr |= ICH_HCR_TC;
}
int vgic_v3_lpi_sync_pending_status(struct kvm *kvm, struct vgic_irq *irq)
@@ -450,6 +453,12 @@
}
early_param("kvm-arm.vgic_v3_group1_trap", early_group1_trap_cfg);
+static int __init early_common_trap_cfg(char *buf)
+{
+ return strtobool(buf, &common_trap);
+}
+early_param("kvm-arm.vgic_v3_common_trap", early_common_trap_cfg);
+
/**
* vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
* @node: pointer to the DT node
@@ -508,7 +517,7 @@
}
#endif
- if (group0_trap || group1_trap) {
+ if (group0_trap || group1_trap || common_trap) {
kvm_info("GICv3 sysreg trapping enabled (reduced performance)\n");
static_branch_enable(&vgic_v3_cpuif_trap);
}