Allow a pseries guest hypervisor (must be a radix guest) to run a hpt
(hash page table) nested guest.
Modify the entry path such that a pseries hypervisor will always use the
kvmhv_run_single_vcpu() function to enter a guest which will result in
it calling H_ENTER_NESTED. Also modify the API to H_ENTER_NESTED to add
a version 2 which adds a slb pointer to the argument list which provides
the slb state to be used to run the nested guest.
Also modify the exit path such that a pseries hypervisor will call
kvmppc_hpte_hv_fault() when handling a page fault which would normally
be called from real mode in book3s_hv_rmhandlers.c on a powernv
hypervisor. This is required for subsequent functions which are invoked
to handle the page fault. Also save the slb state on guest exit and
don't zero slb_max.
Modify kvm_vm_ioctl_get_smmu_info_hv() such that only 4k and 64k page
size support is reported to the guest. This is to ensure that we can
maintain a 1-to-1 mapping between the guest hpt and the shadow hpt for
simplicity (this could be relaxed later with appropriate support) since
a 16M page would likely have to be broken into multiple smaller pages
since the radix guest is likely to at most be backed by 2M pages.
Modify do_tlbies() such that a pseries hypervisor will make the
H_TLB_INVALIDATE hcall to notify it's hypervisor of the invalidation of
partition scoped translation information which is required to keep the
shadow hpt in sync.
Finally allow a pseries hypervisor to run a nested hpt guest by reporting
the KVM_CAP_PPC_MMU_HASH_V3 capability and allowing handling of
kvmhv_configure_mmu().
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx>
---
arch/powerpc/include/asm/hvcall.h | 36 --------------
arch/powerpc/include/asm/kvm_book3s.h | 2 +
arch/powerpc/include/asm/kvm_host.h | 55 +++++++++++++++++++++
arch/powerpc/kvm/book3s_hv.c | 90 ++++++++++++++++++++++++++++-------
arch/powerpc/kvm/book3s_hv_nested.c | 22 ++++++++-
arch/powerpc/kvm/book3s_hv_rm_mmu.c | 20 ++++++++
arch/powerpc/kvm/powerpc.c | 3 +-
7 files changed, 173 insertions(+), 55 deletions(-)
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 11112023e327..19afab30c7d0 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -481,42 +481,6 @@ struct h_cpu_char_result {
u64 behaviour;
};
-/* Register state for entering a nested guest with H_ENTER_NESTED */
-struct hv_guest_state {
- u64 version; /* version of this structure layout */
- u32 lpid;
- u32 vcpu_token;
- /* These registers are hypervisor privileged (at least for writing) */
- u64 lpcr;
- u64 pcr;
- u64 amor;
- u64 dpdes;
- u64 hfscr;
- s64 tb_offset;
- u64 dawr0;
- u64 dawrx0;
- u64 ciabr;
- u64 hdec_expiry;
- u64 purr;
- u64 spurr;
- u64 ic;
- u64 vtb;
- u64 hdar;
- u64 hdsisr;
- u64 heir;
- u64 asdr;
- /* These are OS privileged but need to be set late in guest entry */
- u64 srr0;
- u64 srr1;
- u64 sprg[4];
- u64 pidr;
- u64 cfar;
- u64 ppr;
-};
-
-/* Latest version of hv_guest_state structure */
-#define HV_GUEST_STATE_VERSION 1
-
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_HVCALL_H */
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index c69eeb4e176c..40218e81b75f 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -317,6 +317,8 @@ long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu);
int kvmhv_run_single_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu,
u64 time_limit, unsigned long lpcr);
void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr);
+void kvmhv_save_guest_slb(struct kvm_vcpu *vcpu, struct guest_slb *slbp);
+void kvmhv_restore_guest_slb(struct kvm_vcpu *vcpu, struct guest_slb *slbp);
void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
struct hv_guest_state *hr);
long int kvmhv_nested_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu);
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index e6e5f59aaa97..bad09c213be6 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -813,6 +813,61 @@ struct kvm_vcpu_arch {
#endif /* CONFIG_KVM_BOOK3S_HV_EXIT_TIMING */
};
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+
+/* Following definitions used for the H_ENTER_NESTED hcall parameters */
+
+/* Following structure(s) added in Version 1 */
+
+/* Register state for entering a nested guest with H_ENTER_NESTED */
+struct hv_guest_state {
+ /* version 1 */
+ u64 version; /* version of this structure layout */
+ u32 lpid;
+ u32 vcpu_token;
+ /* These registers are hypervisor privileged (at least for writing) */
+ u64 lpcr;
+ u64 pcr;
+ u64 amor;
+ u64 dpdes;
+ u64 hfscr;
+ s64 tb_offset;
+ u64 dawr0;
+ u64 dawrx0;
+ u64 ciabr;
+ u64 hdec_expiry;
+ u64 purr;
+ u64 spurr;
+ u64 ic;
+ u64 vtb;
+ u64 hdar;
+ u64 hdsisr;
+ u64 heir;
+ u64 asdr;
+ /* These are OS privileged but need to be set late in guest entry */
+ u64 srr0;
+ u64 srr1;
+ u64 sprg[4];
+ u64 pidr;
+ u64 cfar;
+ u64 ppr;
+};
+
+/* Following structure(s) added in Version 2 */
+
+/* SLB state for entering a nested guest with H_ENTER_NESTED */
+struct guest_slb {
+ struct kvmppc_slb slb[64];
+ int slb_max; /* 1 + index of last valid entry in slb[] */
+ int slb_nr; /* total number of entries in SLB */
+};
+
+/* Min and max supported versions of the above structure(s) */
+#define HV_GUEST_STATE_MIN_VERSION 1
+#define HV_GUEST_STATE_MAX_VERSION 2
+
+#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
+
#define VCPU_FPR(vcpu, i) (vcpu)->arch.fp.fpr[i][TS_FPROFFSET]
#define VCPU_VSX_FPR(vcpu, i, j) ((vcpu)->arch.fp.fpr[i][j])
#define VCPU_VSX_VR(vcpu, i) ((vcpu)->arch.vr.vr[i])
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 67e242214191..be72bc6b4cd5 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3434,16 +3434,28 @@ static int kvmhv_pseries_enter_guest(struct kvm_vcpu *vcpu, u64 time_limit,
{
/* call our hypervisor to load up HV regs and go */
struct hv_guest_state hvregs;
+ struct guest_slb *slbp = NULL;
/* we need to save/restore host & guest psscr since L0 doesn't for us */
unsigned long host_psscr;
int trap;
+ if (!kvmhv_vcpu_is_radix(vcpu)) {
+ slbp = kzalloc(sizeof(*slbp), GFP_KERNEL);
+ if (!slbp) {
+ pr_err_ratelimited("KVM: Couldn't alloc hv_guest_slb\n");
+ return 0;
+ }
+ kvmhv_save_guest_slb(vcpu, slbp);
+ hvregs.version = 2; /* V2 required for hpt guest support */
+ } else {
+ hvregs.version = 1; /* V1 sufficient for radix guest */
+ }
+
host_psscr = mfspr(SPRN_PSSCR_PR);
mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
kvmhv_save_hv_regs(vcpu, &hvregs);
hvregs.lpcr = lpcr;
vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
- hvregs.version = HV_GUEST_STATE_VERSION;
if (vcpu->arch.nested) {
hvregs.lpid = vcpu->arch.nested->shadow_lpid;
hvregs.vcpu_token = vcpu->arch.nested_vcpu_id;
@@ -3453,8 +3465,12 @@ static int kvmhv_pseries_enter_guest(struct kvm_vcpu *vcpu, u64 time_limit,
}
hvregs.hdec_expiry = time_limit;
trap = plpar_hcall_norets(H_ENTER_NESTED, __pa(&hvregs),
- __pa(&vcpu->arch.regs));
+ __pa(&vcpu->arch.regs), __pa(slbp));
kvmhv_restore_hv_return_state(vcpu, &hvregs);
+ if (!kvmhv_vcpu_is_radix(vcpu)) {
+ kvmhv_restore_guest_slb(vcpu, slbp);
+ kfree(slbp);
+ }
vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
@@ -3466,6 +3482,49 @@ static int kvmhv_pseries_enter_guest(struct kvm_vcpu *vcpu, u64 time_limit,
kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
kvmppc_nested_cede(vcpu);
trap = 0;
+ } else if ((!kvmhv_vcpu_is_radix(vcpu)) &&
+ (trap == BOOK3S_INTERRUPT_H_DATA_STORAGE ||
+ trap == BOOK3S_INTERRUPT_H_INST_STORAGE)) {
+ bool data = (trap == BOOK3S_INTERRUPT_H_DATA_STORAGE);
+ unsigned long addr, slb_v;
+ unsigned int dsisr;
+ long ret;
+
+ /* NOTE: fault_gpa was reused to store faulting slb entry. */
+ slb_v = vcpu->arch.fault_gpa;
+ if (data) {
+ addr = vcpu->arch.fault_dar;
+ dsisr = vcpu->arch.fault_dsisr;
+ } else {
+ addr = kvmppc_get_pc(vcpu);
+ dsisr = vcpu->arch.shregs.msr & DSISR_SRR1_MATCH_64S;
+ if (vcpu->arch.shregs.msr & HSRR1_HISI_WRITE)
+ dsisr |= DSISR_ISSTORE;
+ }
+
+ /*
+ * kvmppc_hpte_hv_fault is normally called on the exit path in
+ * book3s_hv_rmhandlers.S, however here (for a pseries
+ * hypervisor) we used the H_ENTER_NESTED hcall and so missed
+ * calling it. Thus call is here, now.
+ */
+ ret = kvmppc_hpte_hv_fault(vcpu, addr, slb_v, dsisr, data, 0);
+ if (!ret) { /* let the guest try again */
+ trap = 0;
+ } else if ((!vcpu->arch.nested) && (ret > 0)) {
+ /*
+ * Synthesize a DSI or ISI for the guest
+ * NOTE: don't need to worry about this being a segment
+ * fault since if that was the case the L0 hypervisor
+ * would have delivered this to the nested guest
+ * directly already.
+ */
+ if (data)
+ kvmppc_core_queue_data_storage(vcpu, addr, ret);
+ else
+ kvmppc_core_queue_inst_storage(vcpu, ret);
+ trap = 0;
+ }
}
return trap;
@@ -3682,7 +3741,8 @@ int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
}
- vcpu->arch.slb_max = 0;
+ if (kvm_is_radix(vcpu->kvm))
+ vcpu->arch.slb_max = 0;
dec = mfspr(SPRN_DEC);
if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
dec = (s32) dec;
@@ -4346,9 +4406,12 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
* 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()).
+ * N.B. We need to use the kvmhv_run_single_vcpu() path on
+ * pseries to ensure we call H_ENTER_NESTED.
*/
- if (kvm->arch.threads_indep && kvm_is_radix(kvm) &&
- !no_mixing_hpt_and_radix)
+ if (kvmhv_on_pseries() || (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
@@ -4396,9 +4459,10 @@ static void kvmppc_add_seg_page_size(struct kvm_ppc_one_seg_page_size **sps,
(*sps)->enc[0].page_shift = shift;
(*sps)->enc[0].pte_enc = kvmppc_pgsize_lp_encoding(shift, shift);
/*
- * Add 16MB MPSS support (may get filtered out by userspace)
+ * Add 16MB MPSS support (may get filtered out by userspace) if we're
+ * not running as a nested hypervisor (pseries)
*/
- if (shift != 24) {
+ if (shift != 24 && !kvmhv_on_pseries()) {
int penc = kvmppc_pgsize_lp_encoding(shift, 24);
if (penc != -1) {
(*sps)->enc[1].page_shift = 24;
@@ -4429,11 +4493,9 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm,
sps = &info->sps[0];
kvmppc_add_seg_page_size(&sps, 12, 0);
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;
+ if (!kvmhv_on_pseries()) {
+ kvmppc_add_seg_page_size(&sps, 24, SLB_VSID_L);
+ } /* else no 16M page size support */
return 0;
}
@@ -5362,10 +5424,6 @@ static int kvmhv_configure_mmu(struct kvm *kvm, struct kvm_ppc_mmuv3_cfg *cfg)
if (radix && !radix_enabled())
return -EINVAL;
- /* If we're a nested hypervisor, we currently only support radix */
- if (kvmhv_on_pseries() && !radix)
- return -EINVAL;
-
mutex_lock(&kvm->arch.mmu_setup_lock);
if (radix != kvm_is_radix(kvm)) {
if (kvm->arch.mmu_ready) {
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 735e0ac6f5b2..68d492e8861e 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -51,6 +51,16 @@ void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
hr->ppr = vcpu->arch.ppr;
}
+void kvmhv_save_guest_slb(struct kvm_vcpu *vcpu, struct guest_slb *slbp)
+{
+ int i;
+
+ for (i = 0; i < 64; i++)
+ slbp->slb[i] = vcpu->arch.slb[i];
+ slbp->slb_max = vcpu->arch.slb_max;
+ slbp->slb_nr = vcpu->arch.slb_nr;
+}
+
static void byteswap_pt_regs(struct pt_regs *regs)
{
unsigned long *addr = (unsigned long *) regs;
@@ -169,6 +179,16 @@ static void restore_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
vcpu->arch.ppr = hr->ppr;
}
+void kvmhv_restore_guest_slb(struct kvm_vcpu *vcpu, struct guest_slb *slbp)
+{
+ int i;
+
+ for (i = 0; i < 64; i++)
+ vcpu->arch.slb[i] = slbp->slb[i];
+ vcpu->arch.slb_max = slbp->slb_max;
+ vcpu->arch.slb_nr = slbp->slb_nr;
+}
+
void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
struct hv_guest_state *hr)
{
@@ -239,7 +259,7 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
return H_PARAMETER;
if (kvmppc_need_byteswap(vcpu))
byteswap_hv_regs(&l2_hv);
- if (l2_hv.version != HV_GUEST_STATE_VERSION)
+ if (l2_hv.version != 1)
return H_P2;
regs_ptr = kvmppc_get_gpr(vcpu, 5);
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 1d26d509aaf6..53fe51d04d78 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -446,6 +446,25 @@ static void do_tlbies(unsigned int lpid, unsigned long *rbvalues,
long i;
/*
+ * Handle the case where we're running as a nested hypervisor and so
+ * have to make an hcall to handle invalidations for us.
+ */
+ if (kvmhv_on_pseries()) {
+ unsigned long rc, ric = 0, prs = 0, r = 0;
+
+ for (i = 0; i < npages; i++) {
+ rc = plpar_hcall_norets(H_TLB_INVALIDATE,
+ H_TLBIE_P1_ENC(ric, prs, r),
+ lpid, rbvalues[i]);
+ if (rc)
+ pr_err("KVM: HPT TLB page invalidation hcall failed"
+ ", rc=%ld\n", rc);
+ }
+
+ return;
+ }
+
+ /*
* We use the POWER9 5-operand versions of tlbie and tlbiel here.
* Since we are using RIC=0 PRS=0 R=0, and P7/P8 tlbiel ignores
* the RS field, this is backwards-compatible with P7 and P8.
@@ -1355,3 +1374,4 @@ long kvmppc_hpte_hv_fault(struct kvm_vcpu *vcpu, unsigned long addr,
return -1; /* send fault up to host kernel mode */
}
+EXPORT_SYMBOL_GPL(kvmppc_hpte_hv_fault);
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 3e566c2e6066..b74f794873cd 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -604,8 +604,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
r = !!(hv_enabled && radix_enabled());
break;
case KVM_CAP_PPC_MMU_HASH_V3:
- r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300) &&
- cpu_has_feature(CPU_FTR_HVMODE));
+ r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300));
break;
case KVM_CAP_PPC_NESTED_HV:
r = !!(hv_enabled && kvmppc_hv_ops->enable_nested &&
--
2.13.6
