From ff89511ef29b794d6a9c6b62f5ea76fc013cdae7 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 9 Jun 2017 12:49:53 +0100 Subject: [PATCH] KVM: arm64: Enable GICv3 common sysreg trapping via command-line 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 Acked-by: David Daney Signed-off-by: Marc Zyngier Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall --- 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(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 88bdc421351f..aa8341e73b35 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1837,6 +1837,10 @@ [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) diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h index c7f31a962cfc..6a1f87ff94e2 100644 --- 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 diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c index 35c00efc110b..91cf8b4f01f1 100644 --- 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 @@ void vgic_v3_enable(struct kvm_vcpu *vcpu) 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 @@ static int __init early_group1_trap_cfg(char *buf) } 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 @@ int vgic_v3_probe(const struct gic_kvm_info *info) } #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); }