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

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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>
This commit is contained in:
Cédric Le Goater 2020-06-08 13:57:14 +02:00 committed by Paul Mackerras
parent 4cb4ade19b
commit e55f4d5898
2 changed files with 8 additions and 3 deletions
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3
arch/powerpc/include/asm/reg.h
View File

@ -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 */

8
arch/powerpc/kvm/book3s_64_mmu_hv.c
View File

@ -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);