Commit 2a0c3433 authored by Fuad Tabba's avatar Fuad Tabba Committed by Marc Zyngier
Browse files

KVM: arm64: Initialize trap registers for protected VMs 



Protected VMs have more restricted features that need to be
trapped. Moreover, the host should not be trusted to set the
appropriate trapping registers and their values.

Initialize the trapping registers, i.e., hcr_el2, mdcr_el2, and
cptr_el2 at EL2 for protected guests, based on the values of the
guest's feature id registers.

No functional change intended as trap handlers introduced in the
previous patch are still not hooked in to the guest exit
handlers.

Reviewed-by: default avatarAndrew Jones <drjones@redhat.com>
Signed-off-by: default avatarFuad Tabba <tabba@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211010145636.1950948-9-tabba@google.com
parent 6c30bfb1

arch/arm64/include/asm/kvm_asm.h

+1 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ 
#define __KVM_HOST_SMCCC_FUNC___pkvm_cpu_set_vector		18

#define __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize		19

#define __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc			20

#define __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_init_traps		21



#ifndef __ASSEMBLY__

arch/arm64/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -780,6 +780,8 @@ static inline bool kvm_vm_is_protected(struct kvm *kvm) 
	return false;

}



void kvm_init_protected_traps(struct kvm_vcpu *vcpu);



int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature);

bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);

arch/arm64/kvm/arm.c

+8 −0
Original line number Diff line number Diff line
@@ -620,6 +620,14 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) 


	ret = kvm_arm_pmu_v3_enable(vcpu);



	/*

	 * Initialize traps for protected VMs.

	 * NOTE: Move to run in EL2 directly, rather than via a hypercall, once

	 * the code is in place for first run initialization at EL2.

	 */

	if (kvm_vm_is_protected(kvm))

		kvm_call_hyp_nvhe(__pkvm_vcpu_init_traps, vcpu);



	return ret;

}

arch/arm64/kvm/hyp/include/nvhe/trap_handler.h

+2 −0
Original line number Diff line number Diff line
@@ -15,4 +15,6 @@ 
#define DECLARE_REG(type, name, ctxt, reg)	\

				type name = (type)cpu_reg(ctxt, (reg))



void __pkvm_vcpu_init_traps(struct kvm_vcpu *vcpu);



#endif /* __ARM64_KVM_NVHE_TRAP_HANDLER_H__ */

arch/arm64/kvm/hyp/nvhe/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -14,7 +14,7 @@ lib-objs := $(addprefix ../../../lib/, $(lib-objs)) 


obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \

	 hyp-main.o hyp-smp.o psci-relay.o early_alloc.o stub.o page_alloc.o \

	 cache.o setup.o mm.o mem_protect.o sys_regs.o

	 cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o

obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \

	 ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o

obj-y += $(lib-objs)