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authorNicholas Piggin <npiggin@gmail.com>2022-01-23 22:00:39 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2022-05-13 21:33:33 +1000
commit5d506f159b2b9d0c9bee9bb43ccafb4f291143c2 (patch)
tree3f1af91259d27e3c3b07e7400c36fe38207fec5c /arch/powerpc/kvm
parent18827eeef022df43c1fdeca0fde00ca09405dff1 (diff)
KVM: PPC: Book3S HV: Update LPID allocator init for POWER9, Nested
The LPID allocator init is changed to: - use mmu_lpid_bits rather than hard-coding; - use KVM_MAX_NESTED_GUESTS for nested hypervisors; - not reserve the top LPID on POWER9 and newer CPUs. The reserved LPID is made a POWER7/8-specific detail. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220123120043.3586018-3-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/book3s_64_mmu_hv.c29
-rw-r--r--arch/powerpc/kvm/book3s_hv_rmhandlers.S8
2 files changed, 29 insertions, 8 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index fed4b7652a95..b19347fa2076 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -256,7 +256,7 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
int kvmppc_mmu_hv_init(void)
{
- unsigned long rsvd_lpid;
+ unsigned long nr_lpids;
if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE))
return -EINVAL;
@@ -264,16 +264,29 @@ int kvmppc_mmu_hv_init(void)
if (cpu_has_feature(CPU_FTR_HVMODE)) {
if (WARN_ON(mfspr(SPRN_LPID) != 0))
return -EINVAL;
+ nr_lpids = 1UL << mmu_lpid_bits;
+ } else {
+ nr_lpids = KVM_MAX_NESTED_GUESTS;
}
- /* POWER8 and above have 12-bit LPIDs (10-bit in POWER7) */
- if (cpu_has_feature(CPU_FTR_ARCH_207S))
- rsvd_lpid = LPID_RSVD;
- else
- rsvd_lpid = LPID_RSVD_POWER7;
+ if (nr_lpids > KVMPPC_NR_LPIDS)
+ nr_lpids = KVMPPC_NR_LPIDS;
+
+ if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+ /* POWER7 has 10-bit LPIDs, POWER8 has 12-bit LPIDs */
+ if (cpu_has_feature(CPU_FTR_ARCH_207S))
+ WARN_ON(nr_lpids != 1UL << 12);
+ else
+ WARN_ON(nr_lpids != 1UL << 10);
+
+ /*
+ * Reserve the last implemented LPID use in partition
+ * switching for POWER7 and POWER8.
+ */
+ nr_lpids -= 1;
+ }
- /* rsvd_lpid is reserved for use in partition switching */
- kvmppc_init_lpid(rsvd_lpid);
+ kvmppc_init_lpid(nr_lpids);
return 0;
}
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index d185dee26026..0c552885a032 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -51,6 +51,14 @@
#define STACK_SLOT_FSCR (SFS-96)
/*
+ * Use the last LPID (all implemented LPID bits = 1) for partition switching.
+ * This is reserved in the LPID allocator. POWER7 only implements 0x3ff, but
+ * we write 0xfff into the LPID SPR anyway, which seems to work and just
+ * ignores the top bits.
+ */
+#define LPID_RSVD 0xfff
+
+/*
* Call kvmppc_hv_entry in real mode.
* Must be called with interrupts hard-disabled.
*