From bcc92a0d6d6eae1e7b34a88f58ae69c081d85f97 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Mon, 12 Apr 2021 11:48:37 +1000 Subject: [PATCH] KVM: PPC: Book3S HV: Disallow LPCR[AIL] to be set to 1 or 2 These are already disallowed by H_SET_MODE from the guest, also disallow these by updating LPCR directly. AIL modes can affect the host interrupt behaviour while the guest LPCR value is set, so filter it here too. Suggested-by: Fabiano Rosas Signed-off-by: Nicholas Piggin Acked-by: Paul Mackerras Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210412014845.1517916-5-npiggin@gmail.com --- arch/powerpc/kvm/book3s_hv.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 268e31c7e49cf..3de8a1f89a7db 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -803,7 +803,10 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags, vcpu->arch.dawrx1 = value2; return H_SUCCESS; case H_SET_MODE_RESOURCE_ADDR_TRANS_MODE: - /* KVM does not support mflags=2 (AIL=2) */ + /* + * KVM does not support mflags=2 (AIL=2) and AIL=1 is reserved. + * Keep this in synch with kvmppc_filter_guest_lpcr_hv. + */ if (mflags != 0 && mflags != 3) return H_UNSUPPORTED_FLAG_START; return H_TOO_HARD; @@ -1645,6 +1648,8 @@ unsigned long kvmppc_filter_lpcr_hv(struct kvm *kvm, unsigned long lpcr) /* On POWER8 and above, userspace can modify AIL */ if (!cpu_has_feature(CPU_FTR_ARCH_207S)) lpcr &= ~LPCR_AIL; + if ((lpcr & LPCR_AIL) != LPCR_AIL_3) + lpcr &= ~LPCR_AIL; /* LPCR[AIL]=1/2 is disallowed */ /* * On POWER9, allow userspace to enable large decrementer for the -- 2.30.2