diff options
| author | Amit Machhiwal <amachhiw@linux.ibm.com> | 2025-02-20 12:30:02 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-20 10:18:22 +0200 |
| commit | 81b290aa24490956310d98e2d8e84d53d1899786 (patch) | |
| tree | d99208f91855d4e3c4102a40556da7b812375537 | |
| parent | 434dc66217a986a7115411c5b16de41b262fb899 (diff) | |
KVM: PPC: Enable CAP_SPAPR_TCE_VFIO on pSeries KVM guests
commit b4392813bbc3b05fc01a33c64d8b8c6c62c32cfa upstream.
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 L2 guest 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.
Support for VFIO on pSeries was restored in commit f431a8cde7f1
("powerpc/iommu: Reimplement the iommu_table_group_ops for pSeries"),
making it possible to re-enable this capability on pSeries hosts.
This change enables KVM_CAP_SPAPR_TCE_VFIO for nested PAPR guests on
pSeries, while maintaining the existing behavior on PowerNV. Booting an
L2 guest with 128GB of memory shows an average 11% improvement in
startup time.
Fixes: f431a8cde7f1 ("powerpc/iommu: Reimplement the iommu_table_group_ops for pSeries")
Cc: stable@vger.kernel.org
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250220070002.1478849-1-amachhiw@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/powerpc/kvm/powerpc.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index ce1d91eed231..a7138eb18d59 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -550,12 +550,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) #ifdef CONFIG_PPC_BOOK3S_64 case KVM_CAP_SPAPR_TCE: + fallthrough; case KVM_CAP_SPAPR_TCE_64: - r = 1; - break; case KVM_CAP_SPAPR_TCE_VFIO: - r = !!cpu_has_feature(CPU_FTR_HVMODE); - break; case KVM_CAP_PPC_RTAS: case KVM_CAP_PPC_FIXUP_HCALL: case KVM_CAP_PPC_ENABLE_HCALL: |