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Commit 182936ee authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Enable GICv3 Group-1 sysreg trapping via command-line 



Now that we're able to safely handle Group-1 sysreg access, let's
give the user the opportunity to enable it by passing a specific
command-line option (vgic_v3.group1_trap).

Tested-by: default avatarAlexander Graf <agraf@suse.de>
Acked-by: default avatarDavid Daney <david.daney@cavium.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Acked-by: default avatarChristoffer Dall <cdall@linaro.org>
Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
parent 9c7bfc28

Documentation/admin-guide/kernel-parameters.txt

+4 −0
Original line number Diff line number Diff line
@@ -1829,6 +1829,10 @@ 
			for all guests.

			Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.



	kvm-arm.vgic_v3_group1_trap=

			[KVM,ARM] Trap guest accesses to GICv3 group-1

			system registers



	kvm-intel.ept=	[KVM,Intel] Disable extended page tables

			(virtualized MMU) support on capable Intel chips.

			Default is 1 (enabled)

virt/kvm/arm/vgic/vgic-v3.c

+11 −0
Original line number Diff line number Diff line
@@ -435,6 +435,12 @@ int vgic_v3_map_resources(struct kvm *kvm) 


DEFINE_STATIC_KEY_FALSE(vgic_v3_cpuif_trap);



static int __init early_group1_trap_cfg(char *buf)

{

	return strtobool(buf, &group1_trap);

}

early_param("kvm-arm.vgic_v3_group1_trap", early_group1_trap_cfg);



/**

 * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT

 * @node:	pointer to the DT node
@@ -486,6 +492,11 @@ int vgic_v3_probe(const struct gic_kvm_info *info) 
	if (kvm_vgic_global_state.vcpu_base == 0)

		kvm_info("disabling GICv2 emulation\n");



	if (group1_trap) {

		kvm_info("GICv3 sysreg trapping enabled (reduced performance)\n");

		static_branch_enable(&vgic_v3_cpuif_trap);

	}



	kvm_vgic_global_state.vctrl_base = NULL;

	kvm_vgic_global_state.type = VGIC_V3;

	kvm_vgic_global_state.max_gic_vcpus = VGIC_V3_MAX_CPUS;