Commit 901f8c3f authored by Paul Mackerras's avatar Paul Mackerras
Browse files

KVM: PPC: Book3S HV: Add NO_HASH flag to GET_SMMU_INFO ioctl result 



This adds a KVM_PPC_NO_HASH flag to the flags field of the
kvm_ppc_smmu_info struct, and arranges for it to be set when
running as a nested hypervisor, as an unambiguous indication
to userspace that HPT guests are not supported.  Reporting the
KVM_CAP_PPC_MMU_HASH_V3 capability as false could be taken as
indicating only that the new HPT features in ISA V3.0 are not
supported, leaving it ambiguous whether pre-V3.0 HPT features
are supported.

Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent aa069a99

Documentation/virtual/kvm/api.txt

+4 −0
Original line number Diff line number Diff line
@@ -2270,6 +2270,10 @@ The supported flags are: 
        The emulated MMU supports 1T segments in addition to the

        standard 256M ones.



    - KVM_PPC_NO_HASH

	This flag indicates that HPT guests are not supported by KVM,

	thus all guests must use radix MMU mode.



The "slb_size" field indicates how many SLB entries are supported



The "sps" array contains 8 entries indicating the supported base

arch/powerpc/kvm/book3s_hv.c

+4 −0
Original line number Diff line number Diff line
@@ -4257,6 +4257,10 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm, 
	kvmppc_add_seg_page_size(&sps, 16, SLB_VSID_L | SLB_VSID_LP_01);

	kvmppc_add_seg_page_size(&sps, 24, SLB_VSID_L);



	/* If running as a nested hypervisor, we don't support HPT guests */

	if (kvmhv_on_pseries())

		info->flags |= KVM_PPC_NO_HASH;



	return 0;

}

include/uapi/linux/kvm.h

+1 −0
Original line number Diff line number Diff line
@@ -719,6 +719,7 @@ struct kvm_ppc_one_seg_page_size { 


#define KVM_PPC_PAGE_SIZES_REAL		0x00000001

#define KVM_PPC_1T_SEGMENTS		0x00000002

#define KVM_PPC_NO_HASH			0x00000004



struct kvm_ppc_smmu_info {

	__u64 flags;