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authorPaul Mackerras <paulus@ozlabs.org>2018-10-19 20:44:04 +1100
committerPaul Mackerras <paulus@ozlabs.org>2018-10-19 20:44:04 +1100
commit8d9fcacff9dc4445de4ced2dbe63b792174206d5 (patch)
tree9719bd1b5f23d6308fec1df08f3c9f12bfaa4cbc /arch/powerpc/kvm
parent3d0d0d9b1d805e39456a9d49443d847092cb21ab (diff)
KVM: PPC: Book3S HV: Don't use streamlined entry path on early POWER9 chips
This disables the use of the streamlined entry path for radix guests on early POWER9 chips that need the workaround added in commit a25bd72badfa ("powerpc/mm/radix: Workaround prefetch issue with KVM", 2017-07-24), because the streamlined entry path does not include that workaround. This also means that we can't do nested HV-KVM on those chips. Since the chips that need that workaround are the same ones that can't run both radix and HPT guests at the same time on different threads of a core, we use the existing 'no_mixing_hpt_and_radix' variable that identifies those chips to identify when we can't use the new guest entry path, and when we can't do nested virtualization. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/book3s_hv.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 788bc61bd08c..bf8def2159c3 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4174,7 +4174,16 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
do {
- if (kvm->arch.threads_indep && kvm_is_radix(kvm))
+ /*
+ * The early POWER9 chips that can't mix radix and HPT threads
+ * on the same core also need the workaround for the problem
+ * where the TLB would prefetch entries in the guest exit path
+ * for radix guests using the guest PIDR value and LPID 0.
+ * The workaround is in the old path (kvmppc_run_vcpu())
+ * but not the new path (kvmhv_run_single_vcpu()).
+ */
+ if (kvm->arch.threads_indep && kvm_is_radix(kvm) &&
+ !no_mixing_hpt_and_radix)
r = kvmhv_run_single_vcpu(run, vcpu, ~(u64)0,
vcpu->arch.vcore->lpcr);
else
@@ -5196,7 +5205,7 @@ static int kvmhv_enable_nested(struct kvm *kvm)
{
if (!nested)
return -EPERM;
- if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ if (!cpu_has_feature(CPU_FTR_ARCH_300) || no_mixing_hpt_and_radix)
return -ENODEV;
/* kvm == NULL means the caller is testing if the capability exists */