With mttcg, broadcast tlbie instructions do not wait until other vCPUs
have been kicked out of TCG execution before they complete (including
necessary subsequent tlbsync, etc., instructions). This is contrary to
the ISA, and it permits other vCPUs to use translations after the TLB
flush. For example:
CPU0
// *memP is initially 0, memV maps to memP with *pte
*pte = 0;
ptesync ; tlbie ; eieio ; tlbsync ; ptesync
*memP = 1;
CPU1
assert(*memV == 0);
It is possible for the assertion to fail because CPU1 translates memV
using the TLB after CPU0 has stored 1 to the underlying memory. This
race was observed with a careful test case where CPU1 checks run in a
very large expensive TB so it can run for the entire CPU0 period between
clearing the pte and storing the memory, but host vCPU thread preemption
could cause the race to hit anywhere.
As explained in commit 4ddc104689 ("target/ppc: Fix tlbie"), it is not
enough to just use tlb_flush_all_cpus_synced(), because that does not
execute until the calling CPU has finished its TB. It is also required
that the TB is ended at the point where the TLB flush must subsequently
take effect.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Allow the name 'cpu_env' to be used for something else.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Translators are no longer required to free tcg temporaries.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This initial version supports the invalidation of one or all
TLB entries. Flush by PID/LPID, or based in process/partition
scope is not supported, because it would make using the
generic QEMU TLB implementation hard. In these cases, all
entries are flushed.
Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220712193741.59134-3-leandro.lupori@eldorado.org.br>
[danielhb: moved 'set' declaration to TLBIE_RIC_PWC block]
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Also decode RIC, PRS and R operands.
Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220712193741.59134-2-leandro.lupori@eldorado.org.br>
[danielhb: mark bit 31 in @X_tlbie pattern as ignored]
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
