From e3bfed1df379c18f20feb06427d952b766e2c00f Mon Sep 17 00:00:00 2001
From: Paul Mackerras <paulus@ozlabs.org>
Date: Fri, 25 Aug 2017 19:53:39 +1000
Subject: [PATCH] KVM: PPC: Book3S HV: Report storage key support to userspace
References: bsc#1061840
Patch-mainline: v4.14-rc1
Git-commit: e3bfed1df379c18f20feb06427d952b766e2c00f
This adds information about storage keys to the struct returned by
the KVM_PPC_GET_SMMU_INFO ioctl. The new fields replace a pad field,
which was zeroed by previous kernel versions. Thus userspace that
knows about the new fields will see zeroes when running on an older
kernel, indicating that storage keys are not supported. The size of
the structure has not changed.
The number of keys is hard-coded for the CPUs supported by HV KVM,
which is just POWER7, POWER8 and POWER9.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kvm/book3s_hv.c | 8 ++++++++
include/uapi/linux/kvm.h | 3 ++-
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1182cfd79857..f62ad2e9085f 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3331,6 +3331,14 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm,
if (radix_enabled())
return -EINVAL;
+ /*
+ * POWER7, POWER8 and POWER9 all support 32 storage keys for data.
+ * POWER7 doesn't support keys for instruction accesses,
+ * POWER8 and POWER9 do.
+ */
+ info->data_keys = 32;
+ info->instr_keys = cpu_has_feature(CPU_FTR_ARCH_207S) ? 32 : 0;
+
info->flags = KVM_PPC_PAGE_SIZES_REAL;
if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
info->flags |= KVM_PPC_1T_SEGMENTS;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 6cd63c18708a..838887587411 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -711,7 +711,8 @@ struct kvm_ppc_one_seg_page_size {
struct kvm_ppc_smmu_info {
__u64 flags;
__u32 slb_size;
- __u32 pad;
+ __u16 data_keys; /* # storage keys supported for data */
+ __u16 instr_keys; /* # storage keys supported for instructions */
struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ];
};
--
2.13.6