Subject: [PATCH v1 05/12] KVM: PPC: Book3S HV: Prevent radix guests setting LPCR[TC]

From: Nicholas Piggin <[email-masked]>
Date: Mon, 12 Apr 2021 11:48:38 +1000

Prevent radix guests setting LPCR[TC]. This bit only applies to hash
partitions.

Reviewed-by: Alexey Kardashevskiy <[email-masked]>
Signed-off-by: Nicholas Piggin <[email-masked]>
---
 arch/powerpc/kvm/book3s_hv.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3de8a1f89a7d..70c6e9c27eb7 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1645,6 +1645,10 @@ static int kvm_arch_vcpu_ioctl_set_sregs_hv(struct kvm_vcpu *vcpu,
  */
 unsigned long kvmppc_filter_lpcr_hv(struct kvm *kvm, unsigned long lpcr)
 {
+	/* LPCR_TC only applies to HPT guests */
+	if (kvm_is_radix(kvm))
+		lpcr &= ~LPCR_TC;
+
 	/* On POWER8 and above, userspace can modify AIL */
 	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
 		lpcr &= ~LPCR_AIL;
-- 
2.23.0