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| author | Nicholas Piggin <npiggin@gmail.com> | 2021-06-15 14:41:07 +1000 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2021-07-09 10:38:19 +1000 |
| commit | 17fd09c0212b1595377fd62ade033dcd4147f8b6 (patch) | |
| tree | 4e66229ce34b8982f989decd11ba0cd1b88cf7e7 | |
| parent | 5e994fc019862e77ee8fd2c8808c5fdcf2d249de (diff) | |
| download | qemu-17fd09c0212b1595377fd62ade033dcd4147f8b6.zip qemu-17fd09c0212b1595377fd62ade033dcd4147f8b6.tar.gz qemu-17fd09c0212b1595377fd62ade033dcd4147f8b6.tar.bz2 | |
target/ppc/spapr: Update H_GET_CPU_CHARACTERISTICS L1D cache flush bits
There are several new L1D cache flush bits added to the hcall which reflect
hardware security features for speculative cache access issues.
These behaviours are now being specified as negative in order to simplify
patched kernel compatibility with older firmware (a new problem found in
existing systems would automatically be vulnerable).
[dwg: Technically this changes behaviour for existing machine types.
After discussion with Nick, we've determined this is safe, because
the worst that will happen if a guest gets the wrong information due
to a migration is that it will perform some unnecessary workarounds,
but will remain correct and secure (well, as secure as it was going
to be anyway). In addition the change only affects cap-cfpc=safe
which is not enabled by default, and in fact is not possible to set
on any current hardware (though it's expected it will be possible on
POWER10)]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20210615044107.1481608-1-npiggin@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
| -rw-r--r-- | hw/ppc/spapr_hcall.c | 2 | ||||
| -rw-r--r-- | include/hw/ppc/spapr.h | 3 |
2 files changed, 5 insertions, 0 deletions
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c index 03fc191..80ae8ea 100644 --- a/hw/ppc/spapr_hcall.c +++ b/hw/ppc/spapr_hcall.c @@ -1318,6 +1318,8 @@ static target_ulong h_get_cpu_characteristics(PowerPCCPU *cpu, behaviour |= H_CPU_BEHAV_L1D_FLUSH_PR; break; case SPAPR_CAP_FIXED: + behaviour |= H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY; + behaviour |= H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS; break; default: /* broken */ assert(safe_cache == SPAPR_CAP_BROKEN); diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h index 1e63f33..a25e69f 100644 --- a/include/hw/ppc/spapr.h +++ b/include/hw/ppc/spapr.h @@ -400,10 +400,13 @@ struct SpaprMachineState { #define H_CPU_CHAR_THR_RECONF_TRIG PPC_BIT(6) #define H_CPU_CHAR_CACHE_COUNT_DIS PPC_BIT(7) #define H_CPU_CHAR_BCCTR_FLUSH_ASSIST PPC_BIT(9) + #define H_CPU_BEHAV_FAVOUR_SECURITY PPC_BIT(0) #define H_CPU_BEHAV_L1D_FLUSH_PR PPC_BIT(1) #define H_CPU_BEHAV_BNDS_CHK_SPEC_BAR PPC_BIT(2) #define H_CPU_BEHAV_FLUSH_COUNT_CACHE PPC_BIT(5) +#define H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY PPC_BIT(7) +#define H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS PPC_BIT(8) /* Each control block has to be on a 4K boundary */ #define H_CB_ALIGNMENT 4096 |