diff options
| author | Suraj Jitindar Singh <sjitindarsingh@gmail.com> | 2019-03-01 14:19:11 +1100 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2019-03-12 12:07:49 +1100 |
| commit | 399b2896d4948a1ec0278d896ea3a561df768d64 (patch) | |
| tree | 26e43bfa94cb2f4d70aef260897aaf5121d0f38b /target/ppc/kvm.c | |
| parent | edaa7995591eb51c9ae2c82267ca443f6921ff89 (diff) | |
target/ppc/spapr: Add workaround option to SPAPR_CAP_IBS
The spapr_cap SPAPR_CAP_IBS is used to indicate the level of capability
for mitigations for indirect branch speculation. Currently the available
values are broken (default), fixed-ibs (fixed by serialising indirect
branches) and fixed-ccd (fixed by diabling the count cache).
Introduce a new value for this capability denoted workaround, meaning that
software can work around the issue by flushing the count cache on
context switch. This option is available if the hypervisor sets the
H_CPU_BEHAV_FLUSH_COUNT_CACHE flag in the cpu behaviours returned from
the KVM_PPC_GET_CPU_CHAR ioctl.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190301031912.28809-1-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'target/ppc/kvm.c')
| -rw-r--r-- | target/ppc/kvm.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index f0f5bf9391..4d46314276 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -2392,7 +2392,13 @@ static int parse_cap_ppc_safe_bounds_check(struct kvm_ppc_cpu_char c) static int parse_cap_ppc_safe_indirect_branch(struct kvm_ppc_cpu_char c) { - if (c.character & c.character_mask & H_CPU_CHAR_CACHE_COUNT_DIS) { + if ((~c.behaviour & c.behaviour_mask & H_CPU_BEHAV_FLUSH_COUNT_CACHE) && + (~c.character & c.character_mask & H_CPU_CHAR_CACHE_COUNT_DIS) && + (~c.character & c.character_mask & H_CPU_CHAR_BCCTRL_SERIALISED)) { + return SPAPR_CAP_FIXED_NA; + } else if (c.behaviour & c.behaviour_mask & H_CPU_BEHAV_FLUSH_COUNT_CACHE) { + return SPAPR_CAP_WORKAROUND; + } else if (c.character & c.character_mask & H_CPU_CHAR_CACHE_COUNT_DIS) { return SPAPR_CAP_FIXED_CCD; } else if (c.character & c.character_mask & H_CPU_CHAR_BCCTRL_SERIALISED) { return SPAPR_CAP_FIXED_IBS; |