On Tue, Mar 05, 2019 at 01:21:02PM +1100, Suraj Jitindar Singh wrote:
> If we allocate a hash page table then we know that the guest won't be
> using process tables, so set the partition table entry maintained for
> the guest to zero. If this isn't done, then the guest radix bit will
> remain set in the entry. This means that when the guest calls
> H_REGISTER_PROCESS_TABLE there will be a mismatch between then flags
> and the value in spapr->patb_entry, and the call will fail. The guest
> will then panic:
>
> Failed to register process table (rc=-4)
> kernel BUG at arch/powerpc/platforms/pseries/lpar.c:959
>
> The result being that it isn't possible to boot a hash guest on a P9
> system.
>
> Also fix a bug in the flags parsing in h_register_process_table() which
> was introduced by the same patch, and simplify the handling to make it
> less likely that errors will be introduced in the future. The effect
> would have been setting the host radix bit LPCR_HR for a hash guest
> using process tables, which currently isn't supported and so couldn't
> have been triggered.
>
> Fixes: 00fd075e18 "target/ppc/spapr: Set LPCR:HR when using Radix mode"
>
> Signed-off-by: Suraj Jitindar Singh
Applied, thanks.
> ---
> hw/ppc/spapr.c | 1 +
> hw/ppc/spapr_hcall.c | 12
> 2 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index e39068578e..cf1ef9ebd4 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1632,6 +1632,7 @@ void spapr_reallocate_hpt(sPAPRMachineState *spapr, int
> shift,
> }
> }
> /* We're setting up a hash table, so that means we're not radix */
> +spapr->patb_entry = 0;
> spapr_set_all_lpcrs(0, LPCR_HR | LPCR_UPRT);
> }
>
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 8bfdddc964..7016a09386 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -1339,6 +1339,7 @@ static target_ulong h_register_process_table(PowerPCCPU
> *cpu,
> target_ulong proc_tbl = args[1];
> target_ulong page_size = args[2];
> target_ulong table_size = args[3];
> +target_ulong update_lpcr = 0;
> uint64_t cproc;
>
> if (flags & ~FLAGS_MASK) { /* Check no reserved bits are set */
> @@ -1394,10 +1395,13 @@ static target_ulong
> h_register_process_table(PowerPCCPU *cpu,
> spapr->patb_entry = cproc; /* Save new process table */
>
> /* Update the UPRT, HR and GTSE bits in the LPCR for all cpus */
> -spapr_set_all_lpcrs(((flags & (FLAG_RADIX | FLAG_HASH_PROC_TBL)) ?
> - (LPCR_UPRT | LPCR_HR) : 0) |
> -((flags & FLAG_GTSE) ? LPCR_GTSE : 0),
> -LPCR_UPRT | LPCR_HR | LPCR_GTSE);
> +if (flags & FLAG_RADIX) /* Radix must use process tables, also set
> HR */
> +update_lpcr |= (LPCR_UPRT | LPCR_HR);
> +else if (flags & FLAG_HASH_PROC_TBL) /* Hash with process tables */
> +update_lpcr |= LPCR_UPRT;
> +if (flags & FLAG_GTSE) /* Guest translation shootdown enable */
> +update_lpcr |= FLAG_GTSE;
> +spapr_set_all_lpcrs(update_lpcr, LPCR_UPRT | LPCR_HR | LPCR_GTSE);
>
> if (kvm_enabled()) {
> return kvmppc_configure_v3_mmu(cpu, flags & FLAG_RADIX,
--
David Gibson| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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