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| author | Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> | 2020-07-27 14:29:08 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-07-29 21:09:37 +1000 |
| commit | bf6b7661f41615c0815fce0a3f27acb5fc005470 (patch) | |
| tree | 4054f048ea5e51306efb8e0d2e6c50e8f564b92c /arch/powerpc/platforms/pseries/setup.c | |
| parent | a5a8b258da7861009240b57687dfef47af91b406 (diff) | |
| download | linux-bf6b7661f41615c0815fce0a3f27acb5fc005470.tar.bz2 | |
powerpc/book3s64/radix: Add kernel command line option to disable radix GTSE
This adds a kernel command line option that can be used to disable GTSE support.
Disabling GTSE implies kernel will make hcalls to invalidate TLB entries.
This was done so that we can do VM migration between configs that enable/disable
GTSE support via hypervisor. To migrate a VM from a system that supports
GTSE to a system that doesn't, we can boot the guest with
radix_hcall_invalidate=on, thereby forcing the guest to use hcalls for TLB
invalidates.
The check for hcall availability is done in pSeries_setup_arch so that
the panic message appears on the console. This should only happen on
a hypervisor that doesn't force the guest to hash translation even
though it can't handle the radix GTSE=0 request via CAS. With
radix_hcall_invalidate=on if the hypervisor doesn't support hcall_rpt_invalidate
hcall it should force the LPAR to hash translation.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200727085908.420806-1-aneesh.kumar@linux.ibm.com
Diffstat (limited to 'arch/powerpc/platforms/pseries/setup.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/setup.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index e29c9bf0a3b9..b1a8c72a8c12 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -747,6 +747,11 @@ static void __init pSeries_setup_arch(void) smp_init_pseries(); + if (radix_enabled() && !mmu_has_feature(MMU_FTR_GTSE)) + if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE)) + panic("BUG: Radix support requires either GTSE or RPT_INVALIDATE\n"); + + /* openpic global configuration register (64-bit format). */ /* openpic Interrupt Source Unit pointer (64-bit format). */ /* python0 facility area (mmio) (64-bit format) REAL address. */ |