KVM: PPC: book3s_hv: Add support for PPC970-family processors

This adds support for running KVM guests in supervisor mode on those
PPC970 processors that have a usable hypervisor mode.  Unfortunately,
Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to
1), but the YDL PowerStation does have a usable hypervisor mode.

There are several differences between the PPC970 and POWER7 in how
guests are managed.  These differences are accommodated using the
CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature
bits.  Notably, on PPC970:

* The LPCR, LPID or RMOR registers don't exist, and the functions of
  those registers are provided by bits in HID4 and one bit in HID0.

* External interrupts can be directed to the hypervisor, but unlike
  POWER7 they are masked by MSR[EE] in non-hypervisor modes and use
  SRR0/1 not HSRR0/1.

* There is no virtual RMA (VRMA) mode; the guest must use an RMO
  (real mode offset) area.

* The TLB entries are not tagged with the LPID, so it is necessary to
  flush the whole TLB on partition switch.  Furthermore, when switching
  partitions we have to ensure that no other CPU is executing the tlbie
  or tlbsync instructions in either the old or the new partition,
  otherwise undefined behaviour can occur.

* The PMU has 8 counters (PMC registers) rather than 6.

* The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist.

* The SLB has 64 entries rather than 32.

* There is no mediated external interrupt facility, so if we switch to
  a guest that has a virtual external interrupt pending but the guest
  has MSR[EE] = 0, we have to arrange to have an interrupt pending for
  it so that we can get control back once it re-enables interrupts.  We
  do that by sending ourselves an IPI with smp_send_reschedule after
  hard-disabling interrupts.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 22 insertions, 8 deletions

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 212dcd8fc50b..bc3a2ea94217 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -42,6 +42,8 @@
 #define VRMA_PAGE_ORDER	24
 #define VRMA_VSID	0x1ffffffUL	/* 1TB VSID reserved for VRMA */
 
+/* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */
+#define MAX_LPID_970	63
 #define NR_LPIDS	(LPID_RSVD + 1)
 unsigned long lpid_inuse[BITS_TO_LONGS(NR_LPIDS)];
 
@@ -69,9 +71,6 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
 
 	kvm->arch.sdr1 = __pa(hpt) | (HPT_ORDER - 18);
 	kvm->arch.lpid = lpid;
-	kvm->arch.host_sdr1 = mfspr(SPRN_SDR1);
-	kvm->arch.host_lpid = mfspr(SPRN_LPID);
-	kvm->arch.host_lpcr = mfspr(SPRN_LPCR);
 
 	pr_info("KVM guest htab at %lx, LPID %lx\n", hpt, lpid);
 	return 0;
@@ -128,12 +127,24 @@ void kvmppc_map_vrma(struct kvm *kvm, struct kvm_userspace_memory_region *mem)
 
 int kvmppc_mmu_hv_init(void)
 {
-	if (!cpu_has_feature(CPU_FTR_HVMODE) ||
-	    !cpu_has_feature(CPU_FTR_ARCH_206))
+	unsigned long host_lpid, rsvd_lpid;
+
+	if (!cpu_has_feature(CPU_FTR_HVMODE))
 		return -EINVAL;
+
 	memset(lpid_inuse, 0, sizeof(lpid_inuse));
-	set_bit(mfspr(SPRN_LPID), lpid_inuse);
-	set_bit(LPID_RSVD, lpid_inuse);
+
+	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
+		host_lpid = mfspr(SPRN_LPID);	/* POWER7 */
+		rsvd_lpid = LPID_RSVD;
+	} else {
+		host_lpid = 0;			/* PPC970 */
+		rsvd_lpid = MAX_LPID_970;
+	}
+
+	set_bit(host_lpid, lpid_inuse);
+	/* rsvd_lpid is reserved for use in partition switching */
+	set_bit(rsvd_lpid, lpid_inuse);
 
 	return 0;
 }
@@ -157,7 +168,10 @@ void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
 {
 	struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
 
-	vcpu->arch.slb_nr = 32;		/* Assume POWER7 for now */
+	if (cpu_has_feature(CPU_FTR_ARCH_206))
+		vcpu->arch.slb_nr = 32;		/* POWER7 */
+	else
+		vcpu->arch.slb_nr = 64;
 
 	mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
 	mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;