On 21/07/16 06:55, Sam Bobroff wrote:
> Commit 4322e8c "ppc: Fix 64K pages support in full emulation" added
> the POWERPC_MMU_64K flag to the POWERPC_MMU_2_06 and POWERPC_MMU_2_07
> definitions but not to their "degraded" variants. When running with PR
> KVM, kvm_fixup_page_sizes() removes the POWERPC_MMU_1TSEG flag from
> the MMU value then later ppc_tlb_invalidate_all() expects the value to
> be one from the list, but it isn't because the POWERPC_MMU_64K bit is
> missing from the (otherwise) matching "degraded" entry. This causes
> QEMU to exit with "fatal: Unknown MMU model".
>
> This patch adds the POWERPC_MMU_64K flag to the POWERPC_MMU_2_06a and
> POWERPC_MMU_2_07a values, preventing the error.
>
> Signed-off-by: Sam Bobroff <sam.bobr...@au1.ibm.com>
> ---
> I recently discovered that I can't start QEMU with KVM PR for modern
> pseries machines:
>
> $ rmmod kvm_hv
> $ modprobe kvm-pr
> $ qemu-system-ppc64 -nographic -vga none -machine pseries,accel=kvm
> qemu: fatal: Unknown MMU model
>
> A quick investigation seems to indicate that it's just a missing flag
> in the MMU definition. If it's really that simple then here's a patch
> for it.
>
> Cheers,
> Sam.
>
> target-ppc/cpu-qom.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/target-ppc/cpu-qom.h b/target-ppc/cpu-qom.h
> index 2864105..0f1e011 100644
> --- a/target-ppc/cpu-qom.h
> +++ b/target-ppc/cpu-qom.h
> @@ -71,6 +71,10 @@ enum powerpc_mmu_t {
> #define POWERPC_MMU_1TSEG 0x00020000
> #define POWERPC_MMU_AMR 0x00040000
> #define POWERPC_MMU_64K 0x00080000
> +/* Any entry that include POWERPC_MMU_1TSEG must have a matching
> + * entry without it, because it may be removed by
> + * kvm_fixup_page_sizes() and the new value must exist here.
> + * See ppc_tlb_invalidate_*(). */
> /* 64 bits PowerPC MMU */
> POWERPC_MMU_64B = POWERPC_MMU_64 | 0x00000001,
> /* Architecture 2.03 and later (has LPCR) */
> @@ -81,6 +85,7 @@ 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 +93,7 @@ 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,
> };
>
>
Added David as CC to make sure it gets caught by a PPC maintainer.
ATB,
Mark.
