KVM: PPC: Book3S HV: Increase KVMPPC_NR_LPIDS on POWER8 and POWER9

POWER8 and POWER9 have 12-bit LPIDs. Change LPID_RSVD to support up to
(4096 - 2) guests on these processors. POWER7 is kept the same with a
limitation of (1024 - 2), but it might be time to drop KVM support for
POWER7.

Tested with 2048 guests * 4 vCPUs on a witherspoon system with 512G
RAM and a bit of swap.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 28311e5..caef048 100644 (file)
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -473,7 +473,8 @@
 #ifndef SPRN_LPID
 #define SPRN_LPID      0x13F   /* Logical Partition Identifier */
 #endif
-#define   LPID_RSVD    0x3ff           /* Reserved LPID for partn switching */
+#define   LPID_RSVD_POWER7     0x3ff   /* Reserved LPID for partn switching */
+#define   LPID_RSVD            0xfff   /* Reserved LPID for partn switching */
 #define        SPRN_HMER       0x150   /* Hypervisor maintenance exception reg */
 #define   HMER_DEBUG_TRIG      (1ul << (63 - 17)) /* Debug trigger */
 #define        SPRN_HMEER      0x151   /* Hyp maintenance exception enable reg */

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 7c5a181..38ea396 100644 (file)
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -260,11 +260,15 @@ int kvmppc_mmu_hv_init(void)
        if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE))
                return -EINVAL;
 
-       /* POWER7 has 10-bit LPIDs (12-bit in POWER8) */
        host_lpid = 0;
        if (cpu_has_feature(CPU_FTR_HVMODE))
                host_lpid = mfspr(SPRN_LPID);
-       rsvd_lpid = LPID_RSVD;
+
+       /* 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;
 
        kvmppc_init_lpid(rsvd_lpid + 1);