ARM: KVM: don't special case PC when doing an MMIO (8734f16f) · Commits · 戴 / test

Admitedly, reading a MMIO register to load PC is very weird. Writing PC to a MMIO register is probably even worse. But the architecture doesn't forbid any of these, and injecting a Prefetch Abort is the wrong thing to do anyway. Remove this check altogether, and let the adventurous guest wander into LaLaLand if they feel compelled to do so. Reported-by:

Catalin Marinas <catalin.marinas@arm.com> Acked-by:

Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:

Marc Zyngier <marc.zyngier@arm.com> Signed-off-by:

Christoffer Dall <cdall@cs.columbia.edu>

arch/arm/include/asm/kvm_emulate.h

+0 −5

Original line number	Diff line number	Diff line
		@@ -65,11 +65,6 @@ static inline bool vcpu_mode_priv(struct kvm_vcpu *vcpu)
		return cpsr_mode > USR_MODE;;
		}

		static inline bool kvm_vcpu_reg_is_pc(struct kvm_vcpu *vcpu, int reg)
		{
		return reg == 15;
		}

		static inline u32 kvm_vcpu_get_hsr(struct kvm_vcpu *vcpu)
		{
		return vcpu->arch.fault.hsr;

arch/arm/kvm/mmio.c

+0 −6

Original line number	Diff line number	Diff line
		@@ -86,12 +86,6 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
		sign_extend = kvm_vcpu_dabt_issext(vcpu);
		rt = kvm_vcpu_dabt_get_rd(vcpu);

		if (kvm_vcpu_reg_is_pc(vcpu, rt)) {
		/* IO memory trying to read/write pc */
		kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
		return 1;
		}

		mmio->is_write = is_write;
		mmio->phys_addr = fault_ipa;
		mmio->len = len;

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