Commit afd67ee3 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
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KVM: x86: Don't update vcpu->arch.pv_eoi.msr_val when a bogus value was... 


KVM: x86: Don't update vcpu->arch.pv_eoi.msr_val when a bogus value was written to MSR_KVM_PV_EOI_EN

When kvm_gfn_to_hva_cache_init() call from kvm_lapic_set_pv_eoi() fails,
MSR write to MSR_KVM_PV_EOI_EN results in #GP so it is reasonable to
expect that the value we keep internally in KVM wasn't updated.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211108152819.12485-3-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 77c3323f

arch/x86/kvm/lapic.c

+13 −8
Original line number Diff line number Diff line
@@ -2857,20 +2857,25 @@ int kvm_lapic_set_pv_eoi(struct kvm_vcpu *vcpu, u64 data, unsigned long len) 
	u64 addr = data & ~KVM_MSR_ENABLED;

	struct gfn_to_hva_cache *ghc = &vcpu->arch.pv_eoi.data;

	unsigned long new_len;

	int ret;



	if (!IS_ALIGNED(addr, 4))

		return 1;



	vcpu->arch.pv_eoi.msr_val = data;

	if (!pv_eoi_enabled(vcpu))

		return 0;



	if (data & KVM_MSR_ENABLED) {

		if (addr == ghc->gpa && len <= ghc->len)

			new_len = ghc->len;

		else

			new_len = len;



	return kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, addr, new_len);

		ret = kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, addr, new_len);

		if (ret)

			return ret;

	}



	vcpu->arch.pv_eoi.msr_val = data;



	return 0;

}



int kvm_apic_accept_events(struct kvm_vcpu *vcpu)