Searched hist:"176 dccee" (Results 1 – 2 of 2) sorted by relevance
| /openbmc/qemu/hw/ppc/ |
| H A D | spapr_hcall.c | 49e9fdd7 Tue Mar 12 22:17:27 CDT 2019 David Gibson <david@gibson.dropbear.id.au> spapr: Correctly set LPCR[GTSE] in H_REGISTER_PROCESS_TABLE
176dccee "target/ppc/spapr: Clear partition table entry when allocating
hash table" reworked the H_REGISTER_PROCESS_TABLE hypercall, but
unfortunately due to a small error no longer correctly sets the LPCR[GTSE]
bit which allows the guest to directly execute (some types of) tlbie (TLB
flush) instructions without involving the hypervisor.
We got away with this, initially, because POWER9 did not have hypervisor
mode enabled in its msr_mask, which meant we didn't actually run hypervisor
privilege checks in TCG at all. However, da874d90 "target/ppc: add HV
support for POWER9" turned on HV support on POWER9 for the benefit of the
powernv machine type.
This exposed the earlier bug in H_REGISTER_PROCESS_TABLE, and causes guests
which rely on LPCR[GTSE] (i.e. basically all of them) to crash during early
boot when their first tlbie instruction causes an unexpected trap.
Fixes: 176dccee target/ppc/spapr: Clear partition table entry when allocating hash table
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Cleber Rosa <crosa@redhat.com>
49e9fdd7 Tue Mar 12 22:17:27 CDT 2019 David Gibson <david@gibson.dropbear.id.au> spapr: Correctly set LPCR[GTSE] in H_REGISTER_PROCESS_TABLE
176dccee "target/ppc/spapr: Clear partition table entry when allocating
hash table" reworked the H_REGISTER_PROCESS_TABLE hypercall, but
unfortunately due to a small error no longer correctly sets the LPCR[GTSE]
bit which allows the guest to directly execute (some types of) tlbie (TLB
flush) instructions without involving the hypervisor.
We got away with this, initially, because POWER9 did not have hypervisor
mode enabled in its msr_mask, which meant we didn't actually run hypervisor
privilege checks in TCG at all. However, da874d90 "target/ppc: add HV
support for POWER9" turned on HV support on POWER9 for the benefit of the
powernv machine type.
This exposed the earlier bug in H_REGISTER_PROCESS_TABLE, and causes guests
which rely on LPCR[GTSE] (i.e. basically all of them) to crash during early
boot when their first tlbie instruction causes an unexpected trap.
Fixes: 176dccee target/ppc/spapr: Clear partition table entry when allocating hash table
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Cleber Rosa <crosa@redhat.com>
176dccee Mon Mar 04 20:21:02 CST 2019 Suraj Jitindar Singh <sjitindarsingh@gmail.com> target/ppc/spapr: Clear partition table entry when allocating hash table
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 <sjitindarsingh@gmail.com>
Message-Id: <20190305022102.17610-1-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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| H A D | spapr.c | 176dccee Mon Mar 04 20:21:02 CST 2019 Suraj Jitindar Singh <sjitindarsingh@gmail.com> target/ppc/spapr: Clear partition table entry when allocating hash table
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 <sjitindarsingh@gmail.com>
Message-Id: <20190305022102.17610-1-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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