[PATCH] KVM: PPC: Enable CAP_SPAPR_TCE_VFIO on pSeries KVM guests

From: Amit Machhiwal
Date: Thu Jan 09 2025 - 08:22:16 EST


Currently, on book3s-hv, the capability KVM_CAP_SPAPR_TCE_VFIO is only
available for KVM Guests running on PowerNV and not for the KVM guests
running on pSeries hypervisors. This prevents a pSeries hypervisor from
leveraging the in-kernel acceleration for H_PUT_TCE_INDIRECT and
H_STUFF_TCE hcalls that results in slow startup times for large memory
guests.

Fix this by enabling the CAP_SPAPR_TCE_VFIO on the pSeries hosts for the
nested PAPR guests.

Fixes: f431a8cde7f1 ("powerpc/iommu: Reimplement the iommu_table_group_ops for pSeries")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Amit Machhiwal <amachhiw@xxxxxxxxxxxxx>
---
arch/powerpc/kvm/powerpc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index ce1d91eed231..9c479c7381e4 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -554,7 +554,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
r = 1;
break;
case KVM_CAP_SPAPR_TCE_VFIO:
- r = !!cpu_has_feature(CPU_FTR_HVMODE);
+ r = !!cpu_has_feature(CPU_FTR_HVMODE) || is_kvmppc_hv_enabled(kvm);
break;
case KVM_CAP_PPC_RTAS:
case KVM_CAP_PPC_FIXUP_HCALL:

base-commit: eea6e4b4dfb8859446177c32961c96726d0117be
--
2.47.1