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Commit 59da1cbf authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: vgic-v3: Add hook to handle guest GICv3 sysreg accesses at EL2 



In order to start handling guest access to GICv3 system registers,
let's add a hook that will get called when we trap a system register
access. This is gated by a new static key (vgic_v3_cpuif_trap).

Tested-by: default avatarAlexander Graf <agraf@suse.de>
Acked-by: default avatarDavid Daney <david.daney@cavium.com>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
parent 021234ef

arch/arm64/include/asm/kvm_hyp.h

+1 −0
Original line number Diff line number Diff line
@@ -127,6 +127,7 @@ int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu); 


void __vgic_v3_save_state(struct kvm_vcpu *vcpu);

void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);

int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu);



void __timer_save_state(struct kvm_vcpu *vcpu);

void __timer_restore_state(struct kvm_vcpu *vcpu);

arch/arm64/kvm/hyp/switch.c

+14 −0
Original line number Diff line number Diff line
@@ -350,6 +350,20 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) 
		}

	}



	if (static_branch_unlikely(&vgic_v3_cpuif_trap) &&

	    exit_code == ARM_EXCEPTION_TRAP &&

	    (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 ||

	     kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_CP15_32)) {

		int ret = __vgic_v3_perform_cpuif_access(vcpu);



		if (ret == 1) {

			__skip_instr(vcpu);

			goto again;

		}



		/* 0 falls through to be handled out of EL2 */

	}



	fp_enabled = __fpsimd_enabled();



	__sysreg_save_guest_state(guest_ctxt);

include/kvm/arm_vgic.h

+1 −0
Original line number Diff line number Diff line
@@ -292,6 +292,7 @@ struct vgic_cpu { 
};



extern struct static_key_false vgic_v2_cpuif_trap;

extern struct static_key_false vgic_v3_cpuif_trap;



int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);

void kvm_vgic_early_init(struct kvm *kvm);

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

+38 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/irqchip/arm-gic-v3.h>

#include <linux/kvm_host.h>



#include <asm/kvm_emulate.h>

#include <asm/kvm_hyp.h>



#define vtr_to_max_lr_idx(v)		((v) & 0xf)
@@ -371,3 +372,40 @@ void __hyp_text __vgic_v3_write_vmcr(u32 vmcr) 
{

	write_gicreg(vmcr, ICH_VMCR_EL2);

}



#ifdef CONFIG_ARM64



int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)

{

	int rt;

	u32 esr;

	u32 vmcr;

	void (*fn)(struct kvm_vcpu *, u32, int);

	bool is_read;

	u32 sysreg;



	esr = kvm_vcpu_get_hsr(vcpu);

	if (vcpu_mode_is_32bit(vcpu)) {

		if (!kvm_condition_valid(vcpu))

			return 1;



		sysreg = esr_cp15_to_sysreg(esr);

	} else {

		sysreg = esr_sys64_to_sysreg(esr);

	}



	is_read = (esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ;



	switch (sysreg) {

	default:

		return 0;

	}



	vmcr = __vgic_v3_read_vmcr();

	rt = kvm_vcpu_sys_get_rt(vcpu);

	fn(vcpu, vmcr, rt);



	return 1;

}



#endif

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

+2 −0
Original line number Diff line number Diff line
@@ -429,6 +429,8 @@ int vgic_v3_map_resources(struct kvm *kvm) 
	return ret;

}



DEFINE_STATIC_KEY_FALSE(vgic_v3_cpuif_trap);



/**

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

 * @node:	pointer to the DT node