Hi, when I try to run my guest in KVM-PR mode, current QEMU refuses to start:
$ sudo qemu-system-ppc64 -M pseries,accel=kvm,kvm-type=PR \ -nographic -vga none -cpu POWER8 qemu: fatal: Unknown MMU model 851972 ... followed by a useless register dump. I've bisected the issue, and it seems like the problem has been introduced by this commit here: commit 4322e8ced5aaac7191958f09622d199fe61e2d87 ppc: Fix 64K pages support in full emulation Seems like KVM PR is using the "degraded" ISA variants (without the 1TB segments), but the new POWERPC_MMU_64K flag has not been added to those. Has this been done on purpose, or was this just by accident? I can make KVM PR working again with the following patch: diff --git a/target-ppc/cpu-qom.h b/target-ppc/cpu-qom.h index 2864105..36694cb 100644 --- a/target-ppc/cpu-qom.h +++ b/target-ppc/cpu-qom.h @@ -81,6 +81,7 @@ enum powerpc_mmu_t { | POWERPC_MMU_AMR | 0x00000003, /* Architecture 2.06 "degraded" (no 1T segments) */ POWERPC_MMU_2_06a = POWERPC_MMU_64 | POWERPC_MMU_AMR + | POWERPC_MMU_64K | 0x00000003, /* Architecture 2.07 variant */ POWERPC_MMU_2_07 = POWERPC_MMU_64 | POWERPC_MMU_1TSEG @@ -88,6 +89,7 @@ enum powerpc_mmu_t { | POWERPC_MMU_AMR | 0x00000004, /* Architecture 2.07 "degraded" (no 1T segments) */ POWERPC_MMU_2_07a = POWERPC_MMU_64 | POWERPC_MMU_AMR + | POWERPC_MMU_64K | 0x00000004, }; However, not sure whether this is the right fix ... Cédric, Ben, any ideas? Thomas