[PATCH v5 03/48] KVM: PPC: Book3S HV: Disallow LPCR[AIL] to be set to 1 or 2
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2021-04-01 15:05:32
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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. Acked-by: Paul Mackerras <redacted> Suggested-by: Fabiano Rosas <redacted> Signed-off-by: Nicholas Piggin <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 d2c7626cb960..daded8949a39 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
--
2.23.0