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2018-10-31cputlb: Merge tlb_flush_nocheck into tlb_flush_by_mmuidx_async_workRichard Henderson1-72/+21
The difference between the two sets of APIs is now miniscule. This allows tlb_flush, tlb_flush_all_cpus, and tlb_flush_all_cpus_synced to be merged with their corresponding by_mmuidx functions as well. For accounting, consider mmu_idx_bitmask = ALL_MMUIDX_BITS to be a full flush. Tested-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31cputlb: Move env->vtlb_index to env->tlb_d.vindexRichard Henderson1-3/+2
The rest of the tlb victim cache is per-tlb, the next use index should be as well. Tested-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31cputlb: Split large page tracking per mmu_idxRichard Henderson1-77/+61
The set of large pages in the kernel is probably not the same as the set of large pages in the application. Forcing one range to cover both will flush more often than necessary. This allows tlb_flush_page_async_work to flush just the one mmu_idx implicated, which in turn allows us to remove tlb_check_page_and_flush_by_mmuidx_async_work. Tested-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31cputlb: Move cpu->pending_tlb_flush to env->tlb_c.pending_flushRichard Henderson1-12/+23
Protect it with the tlb_lock instead of using atomics. The move puts it in or near the same cacheline as the lock; using the lock means we don't need a second atomic operation in order to perform the update. Which makes it cheap to also update pending_flush in tlb_flush_by_mmuidx_async_work. Tested-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31cputlb: Remove tcg_enabled hack from tlb_flush_nocheckRichard Henderson1-7/+0
The bugs this was working around were fixed with commits 022d6378c7fd target/unicore32: remove tlb_flush from uc32_init_fn 6e11beecfde0 target/alpha: remove tlb_flush from alpha_cpu_initfn Tested-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31cputlb: Move tlb_lock to CPUTLBCommonRichard Henderson1-24/+24
This is the first of several moves to reduce the size of the CPU_COMMON_TLB macro and improve some locality of refernce. Tested-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18cputlb: read CPUTLBEntry.addr_write atomicallyEmilio G. Cota2-12/+19
Updates can come from other threads, so readers that do not take tlb_lock must use atomic_read to avoid undefined behaviour (UB). This completes the conversion to tlb_lock. This conversion results on average in no performance loss, as the following experiments (run on an Intel i7-6700K CPU @ 4.00GHz) show. 1. aarch64 bootup+shutdown test: - Before: Performance counter stats for 'taskset -c 0 ../img/aarch64/die.sh' (10 runs): 7487.087786 task-clock (msec) # 0.998 CPUs utilized ( +- 0.12% ) 31,574,905,303 cycles # 4.217 GHz ( +- 0.12% ) 57,097,908,812 instructions # 1.81 insns per cycle ( +- 0.08% ) 10,255,415,367 branches # 1369.747 M/sec ( +- 0.08% ) 173,278,962 branch-misses # 1.69% of all branches ( +- 0.18% ) 7.504481349 seconds time elapsed ( +- 0.14% ) - After: Performance counter stats for 'taskset -c 0 ../img/aarch64/die.sh' (10 runs): 7462.441328 task-clock (msec) # 0.998 CPUs utilized ( +- 0.07% ) 31,478,476,520 cycles # 4.218 GHz ( +- 0.07% ) 57,017,330,084 instructions # 1.81 insns per cycle ( +- 0.05% ) 10,251,929,667 branches # 1373.804 M/sec ( +- 0.05% ) 173,023,787 branch-misses # 1.69% of all branches ( +- 0.11% ) 7.474970463 seconds time elapsed ( +- 0.07% ) 2. SPEC06int: SPEC06int (test set) [Y axis: Speedup over master] 1.15 +-+----+------+------+------+------+------+-------+------+------+------+------+------+------+----+-+ | | 1.1 +-+.................................+++.............................+ tlb-lock-v2 (m+++x) +-+ | +++ | +++ tlb-lock-v3 (spinl|ck) | | +++ | | +++ +++ | | | 1.05 +-+....+++...........####.........|####.+++.|......|.....###....+++...........+++....###.........+-+ | ### ++#| # |# |# ***### +++### +++#+# | +++ | #|# ### | 1 +-+++***+#++++####+++#++#++++++++++#++#+*+*++#++++#+#+****+#++++###++++###++++###++++#+#++++#+#+++-+ | *+* # #++# *** # #### *** # * *++# ****+# *| * # ****|# |# # #|# #+# # # | 0.95 +-+..*.*.#....#..#.*|*..#...#..#.*|*..#.*.*..#.*|.*.#.*++*.#.*++*+#.****.#....#+#....#.#..++#.#..+-+ | * * # # # *|* # # # *|* # * * # *++* # * * # * * # * |* # ++# # # # *** # | | * * # ++# # *+* # # # *|* # * * # * * # * * # * * # *++* # **** # ++# # * * # | 0.9 +-+..*.*.#...|#..#.*.*..#.++#..#.*|*..#.*.*..#.*..*.#.*..*.#.*..*.#.*..*.#.*.|*.#...|#.#..*.*.#..+-+ | * * # *** # * * # |# # *+* # * * # * * # * * # * * # * * # *++* # |# # * * # | 0.85 +-+..*.*.#..*|*..#.*.*..#.***..#.*.*..#.*.*..#.*..*.#.*..*.#.*..*.#.*..*.#.*..*.#.****.#..*.*.#..+-+ | * * # *+* # * * # *|* # * * # * * # * * # * * # * * # * * # * * # * |* # * * # | | * * # * * # * * # *+* # * * # * * # * * # * * # * * # * * # * * # * |* # * * # | 0.8 +-+..*.*.#..*.*..#.*.*..#.*.*..#.*.*..#.*.*..#.*..*.#.*..*.#.*..*.#.*..*.#.*..*.#.*++*.#..*.*.#..+-+ | * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # | 0.75 +-+--***##--***###-***###-***###-***###-***###-****##-****##-****##-****##-****##-****##--***##--+-+ 400.perlben401.bzip2403.gcc429.m445.gob456.hmme45462.libqua464.h26471.omnet473483.xalancbmkgeomean png: https://imgur.com/a/BHzpPTW Notes: - tlb-lock-v2 corresponds to an implementation with a mutex. - tlb-lock-v3 corresponds to the current implementation, i.e. a spinlock and a single lock acquisition in tlb_set_page_with_attrs. Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <20181016153840.25877-1-cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18tcg: Split CONFIG_ATOMIC128Richard Henderson3-7/+21
GCC7+ will no longer advertise support for 16-byte __atomic operations if only cmpxchg is supported, as for x86_64. Fortunately, x86_64 still has support for __sync_compare_and_swap_16 and we can make use of that. AArch64 does not have, nor ever has had such support, so open-code it. Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18tcg: Add tlb_index and tlb_entry helpersRichard Henderson2-63/+61
Isolate the computation of an index from an address into a helper before we change that function. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> [ cota: convert tlb_vaddr_to_host; use atomic_read on addr_write ] Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <20181009175129.17888-2-cota@braap.org>
2018-10-18cputlb: serialize tlb updates with env->tlb_lockEmilio G. Cota1-71/+84
Currently we rely on atomic operations for cross-CPU invalidations. There are two cases that these atomics miss: cross-CPU invalidations can race with either (1) vCPU threads flushing their TLB, which happens via memset, or (2) vCPUs calling tlb_reset_dirty on their TLB, which updates .addr_write with a regular store. This results in undefined behaviour, since we're mixing regular and atomic ops on concurrent accesses. Fix it by using tlb_lock, a per-vCPU lock. All updaters of tlb_table and the corresponding victim cache now hold the lock. The readers that do not hold tlb_lock must use atomic reads when reading .addr_write, since this field can be updated by other threads; the conversion to atomic reads is done in the next patch. Note that an alternative fix would be to expand the use of atomic ops. However, in the case of TLB flushes this would have a huge performance impact, since (1) TLB flushes can happen very frequently and (2) we currently use a full memory barrier to flush each TLB entry, and a TLB has many entries. Instead, acquiring the lock is barely slower than a full memory barrier since it is uncontended, and with a single lock acquisition we can flush the entire TLB. Tested-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <20181009174557.16125-6-cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18cputlb: fix assert_cpu_is_self macroEmilio G. Cota1-2/+2
Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <20181009174557.16125-5-cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18exec: introduce tlb_initEmilio G. Cota1-0/+4
Paves the way for the addition of a per-TLB lock. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <20181009174557.16125-4-cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18tcg: access cpu->icount_decr.u16.high with atomicsEmilio G. Cota2-2/+2
Consistently access u16.high with atomics to avoid undefined behaviour in MTTCG. Note that icount_decr.u16.low is only used in icount mode, so regular accesses to it are OK. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <20181010144853.13005-2-cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18tcg: Implement CPU_LOG_TB_NOCHAIN during expansionRichard Henderson1-1/+1
Rather than test NOCHAIN before linking, do not emit the goto_tb opcode at all. We already do this for goto_ptr. Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-02accel/tcg: Remove dead codeThomas Huth1-9/+0
The global cpu_single_env variable has been removed more than 5 years ago, so apparently nobody used this dead debug code in that timeframe anymore. Thus let's remove it completely now. Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <1537204134-15905-1-git-send-email-thuth@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-02translator: fix breakpoint processingPavel Dovgalyuk1-2/+6
QEMU cannot pass through the breakpoints when 'si' command is used in remote gdb. This patch disables inserting the breakpoints when we are already single stepping though the gdb remote protocol. This patch also fixes icount calculation for the blocks that include breakpoints - instruction with breakpoint is not executed and shouldn't be used in icount calculation. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Message-Id: <20180912081910.3228.8523.stgit@pasha-VirtualBox> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-26qht: drop ht argument from qht iteratorsEmilio G. Cota1-4/+2
Accessing the HT from an iterator results almost always in a deadlock. Given that only one qht-internal function uses this argument, drop it from the interface. Suggested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-08-14accel/tcg: Check whether TLB entry is RAM consistently with how we set it upPeter Maydell1-21/+8
We set up TLB entries in tlb_set_page_with_attrs(), where we have some logic for determining whether the TLB entry is considered to be RAM-backed, and thus has a valid addend field. When we look at the TLB entry in get_page_addr_code(), we use different logic for determining whether to treat the page as RAM-backed and use the addend field. This is confusing, and in fact buggy, because the code in tlb_set_page_with_attrs() correctly decides that rom_device memory regions not in romd mode are not RAM-backed, but the code in get_page_addr_code() thinks they are RAM-backed. This typically results in "Bad ram pointer" assertion if the guest tries to execute from such a memory region. Fix this by making get_page_addr_code() just look at the TLB_MMIO bit in the code_address field of the TLB, which tlb_set_page_with_attrs() sets if and only if the addend field is not valid for code execution. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 20180713150945.12348-1-peter.maydell@linaro.org
2018-08-14accel/tcg: Return -1 for execution from MMIO regions in get_page_addr_code()Peter Maydell1-85/+10
Now that all the callers can handle get_page_addr_code() returning -1, remove all the code which tries to handle execution from MMIO regions or small-MMU-region RAM areas. This will mean that we can correctly execute from these areas, rather than ending up either aborting QEMU or delivering an incorrect guest exception. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Tested-by: Cédric Le Goater <clg@kaod.org> Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 20180710160013.26559-6-peter.maydell@linaro.org
2018-08-14accel/tcg: tb_gen_code(): Create single-insn TB for execution from non-RAMPeter Maydell1-1/+18
If get_page_addr_code() returns -1, this indicates that there is no RAM page we can read a full TB from. Instead we must create a TB which contains a single instruction and which we do not cache, so it is executed only once. Since this means we can now have TBs which are not in any page list, we also need to make tb_phys_invalidate() handle them (by not trying to remove them from a nonexistent page list). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Tested-by: Cédric Le Goater <clg@kaod.org> Message-id: 20180710160013.26559-5-peter.maydell@linaro.org
2018-08-14accel/tcg: Handle get_page_addr_code() returning -1 in tb_check_watchpoint()Peter Maydell1-1/+3
When we support execution from non-RAM MMIO regions, get_page_addr_code() will return -1 to indicate that there is no RAM at the requested address. Handle this in tb_check_watchpoint() -- if the exception happened for a PC which doesn't correspond to RAM then there is no need to invalidate any TBs, because the one-instruction TB will not have been cached. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Cédric Le Goater <clg@kaod.org> Message-id: 20180710160013.26559-4-peter.maydell@linaro.org
2018-08-14accel/tcg: Handle get_page_addr_code() returning -1 in hashtable lookupsPeter Maydell1-0/+3
When we support execution from non-RAM MMIO regions, get_page_addr_code() will return -1 to indicate that there is no RAM at the requested address. Handle this in the cpu-exec TB hashtable lookup code, treating it as "no match found". Note that the call to get_page_addr_code() in tb_lookup_cmp() needs no changes -- a return of -1 will already correctly result in the function returning false. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Tested-by: Cédric Le Goater <clg@kaod.org> Message-id: 20180710160013.26559-3-peter.maydell@linaro.org
2018-08-14accel/tcg: Pass read access type through to io_readx()Peter Maydell2-6/+10
The io_readx() function needs to know whether the load it is doing is an MMU_DATA_LOAD or an MMU_INST_FETCH, so that it can pass the right value to the cpu_transaction_failed() function. Plumb this information through from the softmmu code. This is currently not often going to give the wrong answer, because usually instruction fetches go via get_page_addr_code(). However once we switch over to handling execution from non-RAM by creating single-insn TBs, the path for an insn fetch to generate a bus error will be through cpu_ld*_code() and io_readx(), so without this change we will generate a d-side fault when we should generate an i-side fault. We also have to pass the access type via a CPU struct global down to unassigned_mem_read(), for the benefit of the targets which still use the cpu_unassigned_access() hook (m68k, mips, sparc, xtensa). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Tested-by: Cédric Le Goater <clg@kaod.org> Message-id: 20180710160013.26559-2-peter.maydell@linaro.org
2018-07-17Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into stagingPeter Maydell1-1/+1
Bug fixes. # gpg: Signature made Tue 17 Jul 2018 16:06:07 BST # gpg: using RSA key BFFBD25F78C7AE83 # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" # Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1 # Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83 * remotes/bonzini/tags/for-upstream: Document command line options with single dash opts: remove redundant check for NULL parameter i386: only parse the initrd_filename once for multiboot modules i386: fix regression parsing multiboot initrd modules virtio-scsi: fix hotplug ->reset() vs event race qdev: add HotplugHandler->post_plug() callback hw/char/serial: retry write if EAGAIN PC Chipset: Improve serial divisor calculation vhost-user-test: added proper TestServer *dest initialization in test_migrate() hyperv: ensure VP index equal to QEMU cpu_index hyperv: rename vcpu_id to vp_index accel: Fix typo and grammar in comment dump: add kernel_gs_base to QEMU CPU state Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-16accel/tcg: Assert that tlb fill gave us a valid TLB entryPeter Maydell1-2/+2
In commit 4b1a3e1e34ad97 we added a check for whether the TLB entry we had following a tlb_fill had the INVALID bit set. This could happen in some circumstances because a stale or wrong TLB entry was pulled out of the victim cache. However, after commit 68fea038553039e (which prevents stale entries being in the victim cache) and the previous commit (which ensures we don't incorrectly hit in the victim cache)) this should never be possible. Drop the check on TLB_INVALID_MASK from the "is this a TLB_RECHECK?" condition, and instead assert that the tlb fill procedure has given us a valid TLB entry (or longjumped out with a guest exception). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20180713141636.18665-3-peter.maydell@linaro.org
2018-07-16accel/tcg: Use correct test when looking in victim TLB for codePeter Maydell1-1/+1
In get_page_addr_code(), we were incorrectly looking in the victim TLB for an entry which matched the target address for reads, not for code accesses. This meant that we could hit on a victim TLB entry that indicated that the address was readable but not executable, and incorrectly bypass the call to tlb_fill() which should generate the guest MMU exception. Fix this bug. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20180713141636.18665-2-peter.maydell@linaro.org
2018-07-16accel: Fix typo and grammar in commentStefan Weil1-1/+1
The typo was found by codespell. Signed-off-by: Stefan Weil <sw@weilnetz.de> Message-Id: <20180712194454.26765-1-sw@weilnetz.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-07-09translate-all: honour CF_NOCACHE in tb_gen_codeEmilio G. Cota1-15/+19
This fixes a record-replay regression introduced by 95590e2 ("translate-all: discard TB when tb_link_page returns an existing matching TB", 2018-06-15). The problem is that code using CF_NOCACHE assumes that the TB returned from tb_gen_code is always a newly-generated one. This assumption, however, was broken in the aforementioned commit. Fix it by honouring CF_NOCACHE, so that tb_gen_code always returns a newly-generated TB when CF_NOCACHE is passed to it. Do this by avoiding the TB hash table if CF_NOCACHE is set. Reported-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Tested-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Signed-off-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Alistair Francis <alistair.francis@wdc.com> Message-id: 1530806837-5416-1-git-send-email-cota@braap.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-02accel/tcg: Avoid caching overwritten tlb entriesRichard Henderson1-26/+35
When installing a TLB entry, remove any cached version of the same page in the VTLB. If the existing TLB entry matches, do not copy into the VTLB, but overwrite it. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-07-02accel/tcg: Don't treat invalid TLB entries as needing recheckPeter Maydell1-1/+2
In get_page_addr_code() when we check whether the TLB entry is marked as TLB_RECHECK, we should not go down that code path if the TLB entry is not valid at all (ie the TLB_INVALID bit is set). Tested-by: Laurent Vivier <laurent@vivier.eu> Reported-by: Laurent Vivier <laurent@vivier.eu> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20180629161731.16239-1-peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-07-02accel/tcg: Correct "is this a TLB miss" check in get_page_addr_code()Peter Maydell1-2/+1
In commit 71b9a45330fe220d1 we changed the condition we use to determine whether we need to refill the TLB in get_page_addr_code() to if (unlikely(env->tlb_table[mmu_idx][index].addr_code != (addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK)))) { This isn't the right check (it will falsely fail if the input addr happens to have the low bit corresponding to TLB_INVALID_MASK set, for instance). Replace it with a use of the new tlb_hit() function, which is the correct test. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20180629162122.19376-3-peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-07-02tcg: Define and use new tlb_hit() and tlb_hit_page() functionsPeter Maydell2-20/+11
The condition to check whether an address has hit against a particular TLB entry is not completely trivial. We do this in various places, and in fact in one place (get_page_addr_code()) we have got the condition wrong. Abstract it out into new tlb_hit() and tlb_hit_page() inline functions (one for a known-page-aligned address and one for an arbitrary address), and use them in all the places where we had the condition correct. This is a no-behaviour-change patch; we leave fixing the buggy code in get_page_addr_code() to a subsequent patch. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20180629162122.19376-2-peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-07-02translate-all: fix locking of TBs whose two pages share the same physical pageEmilio G. Cota1-7/+25
Commit 0b5c91f ("translate-all: use per-page locking in !user-mode", 2018-06-15) introduced per-page locking. It assumed that the physical pages corresponding to a TB (at most two pages) are always distinct, which is wrong. For instance, an xtensa test provided by Max Filippov is broken by the commit, since the test maps two virtual pages to the same physical page: virt1: 7fff, virt2: 8000 phys1 6000fff, phys2 6000000 Fix it by removing the assumption from page_lock_pair. If the two physical page addresses are equal, we only lock the PageDesc once. Note that the two callers of page_lock_pair, namely page_unlock_tb and tb_link_page, are also updated so that we do not try to unlock the same PageDesc twice. Fixes: 0b5c91f74f3c83a36f37740969df8c775c997e69 Reported-by: Max Filippov <jcmvbkbc@gmail.com> Tested-by: Max Filippov <jcmvbkbc@gmail.com> Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <1529944302-14186-1-git-send-email-cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-29Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into stagingPeter Maydell3-23/+9
* "info mtree" improvements (Alexey) * fake VPD block limits for SCSI passthrough (Daniel Barboza) * chardev and main loop fixes (Daniel Berrangé, Sergio, Stefan) * help fixes (Eduardo) * pc-dimm refactoring (David) * tests improvements and fixes (Emilio, Thomas) * SVM emulation fixes (Jan) * MemoryRegionCache fix (Eric) * WHPX improvements (Justin) * ESP cleanup (Mark) * -overcommit option (Michael) * qemu-pr-helper fixes (me) * "info pic" improvements for x86 (Peter) * x86 TCG emulation fixes (Richard) * KVM slot handling fix (Shannon) * Next round of deprecation (Thomas) * Windows dump format support (Viktor) # gpg: Signature made Fri 29 Jun 2018 12:03:05 BST # gpg: using RSA key BFFBD25F78C7AE83 # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" # Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1 # Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83 * remotes/bonzini/tags/for-upstream: (60 commits) tests/boot-serial: Do not delete the output file in case of errors hw/scsi: add VPD Block Limits emulation hw/scsi: centralize SG_IO calls into single function hw/scsi: cleanups before VPD BL emulation dump: add Windows live system dump dump: add fallback KDBG using in Windows dump dump: use system context in Windows dump dump: add Windows dump format to dump-guest-memory i386/cpu: make -cpu host support monitor/mwait kvm: support -overcommit cpu-pm=on|off hmp: obsolete "info ioapic" ioapic: support "info irq" ioapic: some proper indents when dump info ioapic: support "info pic" doc: another fix to "info pic" target-i386: Mark cpu_vmexit noreturn target-i386: Allow interrupt injection after STGI target-i386: Add NMI interception to SVM memory/hmp: Print owners/parents in "info mtree" WHPX: register for unrecognized MSR exits ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-06-29i386/cpu: make -cpu host support monitor/mwaitMichael S. Tsirkin1-0/+3
When guest CPU PM is enabled, and with -cpu host, expose the host CPU MWAIT leaf in the CPUID so guest can make good PM decisions. Note: the result is 100% CPU utilization reported by host as host no longer knows that the CPU is halted. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com> Message-Id: <20180622192148.178309-3-mst@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-28move public invalidate APIs out of translate-all.{c,h}, clean upPaolo Bonzini2-23/+6
Place them in exec.c, exec-all.h and ram_addr.h. This removes knowledge of translate-all.h (which is an internal header) from several files outside accel/tcg and removes knowledge of AddressSpace from translate-all.c (as it only operates on ram_addr_t). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-28Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into ↵Peter Maydell1-1/+1
staging Pull request * Gracefully handle Linux AIO init failure # gpg: Signature made Wed 27 Jun 2018 15:48:28 BST # gpg: using RSA key 9CA4ABB381AB73C8 # gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" # gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" # Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8 * remotes/stefanha/tags/block-pull-request: linux-aio: properly bubble up errors from initialization compiler: add a sizeof_field() macro Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-06-27compiler: add a sizeof_field() macroStefan Hajnoczi1-1/+1
Determining the size of a field is useful when you don't have a struct variable handy. Open-coding this is ugly. This patch adds the sizeof_field() macro, which is similar to typeof_field(). Existing instances are updated to use the macro. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20180614164431.29305-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-27trace: enable tracing of TCG atomicsEmilio G. Cota1-6/+81
We do not trace guest atomic accesses. Fix it. Tested with a modified atomic_add-bench so that it executes a deterministic number of instructions, i.e. fixed seeding, no threading and fixed number of loop iterations instead of running for a certain time. Before: - With parallel_cpus = false (no clone syscall so it is never set to true): 220070 memory accesses - With parallel_cpus = true (hard-coded): 212105 memory accesses <-- we're not tracing the atomics! After: 220070 memory accesses regardless of parallel_cpus. Signed-off-by: Emilio G. Cota <cota@braap.org> Message-id: 1527028012-21888-6-git-send-email-cota@braap.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-26tcg: Support MMU protection regions smaller than TARGET_PAGE_SIZEPeter Maydell2-28/+125
Add support for MMU protection regions that are smaller than TARGET_PAGE_SIZE. We do this by marking the TLB entry for those pages with a flag TLB_RECHECK. This flag causes us to always take the slow-path for accesses. In the slow path we can then special case them to always call tlb_fill() again, so we have the correct information for the exact address being accessed. This change allows us to handle reading and writing from small regions; we cannot deal with execution from the small region. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20180620130619.11362-2-peter.maydell@linaro.org
2018-06-15tcg: remove tb_lockEmilio G. Cota3-119/+50
Use mmap_lock in user-mode to protect TCG state and the page descriptors. In !user-mode, each vCPU has its own TCG state, so no locks needed. Per-page locks are used to protect the page descriptors. Per-TB locks are used in both modes to protect TB jumps. Some notes: - tb_lock is removed from notdirty_mem_write by passing a locked page_collection to tb_invalidate_phys_page_fast. - tcg_tb_lookup/remove/insert/etc have their own internal lock(s), so there is no need to further serialize access to them. - do_tb_flush is run in a safe async context, meaning no other vCPU threads are running. Therefore acquiring mmap_lock there is just to please tools such as thread sanitizer. - Not visible in the diff, but tb_invalidate_phys_page already has an assert_memory_lock. - cpu_io_recompile is !user-only, so no mmap_lock there. - Added mmap_unlock()'s before all siglongjmp's that could be called in user-mode while mmap_lock is held. + Added an assert for !have_mmap_lock() after returning from the longjmp in cpu_exec, just like we do in cpu_exec_step_atomic. Performance numbers before/after: Host: AMD Opteron(tm) Processor 6376 ubuntu 17.04 ppc64 bootup+shutdown time 700 +-+--+----+------+------------+-----------+------------*--+-+ | + + + + + *B | | before ***B*** ** * | |tb lock removal ###D### *** | 600 +-+ *** +-+ | ** # | | *B* #D | | *** * ## | 500 +-+ *** ### +-+ | * *** ### | | *B* # ## | | ** * #D# | 400 +-+ ** ## +-+ | ** ### | | ** ## | | ** # ## | 300 +-+ * B* #D# +-+ | B *** ### | | * ** #### | | * *** ### | 200 +-+ B *B #D# +-+ | #B* * ## # | | #* ## | | + D##D# + + + + | 100 +-+--+----+------+------------+-----------+------------+--+-+ 1 8 16 Guest CPUs 48 64 png: https://imgur.com/HwmBHXe debian jessie aarch64 bootup+shutdown time 90 +-+--+-----+-----+------------+------------+------------+--+-+ | + + + + + + | | before ***B*** B | 80 +tb lock removal ###D### **D +-+ | **### | | **## | 70 +-+ ** # +-+ | ** ## | | ** # | 60 +-+ *B ## +-+ | ** ## | | *** #D | 50 +-+ *** ## +-+ | * ** ### | | **B* ### | 40 +-+ **** # ## +-+ | **** #D# | | ***B** ### | 30 +-+ B***B** #### +-+ | B * * # ### | | B ###D# | 20 +-+ D ##D## +-+ | D# | | + + + + + + | 10 +-+--+-----+-----+------------+------------+------------+--+-+ 1 8 16 Guest CPUs 48 64 png: https://imgur.com/iGpGFtv The gains are high for 4-8 CPUs. Beyond that point, however, unrelated lock contention significantly hurts scalability. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15translate-all: remove tb_lock mention from cpu_restore_state_from_tbEmilio G. Cota1-1/+0
tb_lock was needed when the function did retranslation. However, since fca8a500d519 ("tcg: Save insn data and use it in cpu_restore_state_from_tb") we don't do retranslation. Get rid of the comment. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15cputlb: remove tb_lock from tlb_flush functionsEmilio G. Cota1-8/+0
The acquisition of tb_lock was added when the async tlb_flush was introduced in e3b9ca810 ("cputlb: introduce tlb_flush_* async work.") tb_lock was there to allow us to do memset() on the tb_jmp_cache's. However, since f3ced3c5928 ("tcg: consistently access cpu->tb_jmp_cache atomically") all accesses to tb_jmp_cache are atomic, so tb_lock is not needed here. Get rid of it. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15translate-all: protect TB jumps with a per-destination-TB lockEmilio G. Cota2-61/+98
This applies to both user-mode and !user-mode emulation. Instead of relying on a global lock, protect the list of incoming jumps with tb->jmp_lock. This lock also protects tb->cflags, so update all tb->cflags readers outside tb->jmp_lock to use atomic reads via tb_cflags(). In order to find the destination TB (and therefore its jmp_lock) from the origin TB, we introduce tb->jmp_dest[]. I considered not using a linked list of jumps, which simplifies code and makes the struct smaller. However, it unnecessarily increases memory usage, which results in a performance decrease. See for instance these numbers booting+shutting down debian-arm: Time (s) Rel. err (%) Abs. err (s) Rel. slowdown (%) ------------------------------------------------------------------------------ before 20.88 0.74 0.154512 0. after 20.81 0.38 0.079078 -0.33524904 GTree 21.02 0.28 0.058856 0.67049808 GHashTable + xxhash 21.63 1.08 0.233604 3.5919540 Using a hash table or a binary tree to keep track of the jumps doesn't really pay off, not only due to the increased memory usage, but also because most TBs have only 0 or 1 jumps to them. The maximum number of jumps when booting debian-arm that I measured is 35, but as we can see in the histogram below a TB with that many incoming jumps is extremely rare; the average TB has 0.80 incoming jumps. n_jumps: 379208; avg jumps/tb: 0.801099 dist: [0.0,1.0)|▄█▁▁▁▁▁▁▁▁▁▁▁ ▁▁▁▁▁▁ ▁▁▁ ▁▁▁ ▁|[34.0,35.0] Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15translate-all: discard TB when tb_link_page returns an existing matching TBEmilio G. Cota2-21/+43
Use the recently-gained QHT feature of returning the matching TB if it already exists. This allows us to get rid of the lookup we perform right after acquiring tb_lock. Suggested-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15translate-all: introduce assert_no_pages_lockedEmilio G. Cota2-0/+8
The appended adds assertions to make sure we do not longjmp with page locks held. Note that user-mode has nothing to check, since page_locks are !user-mode only. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15translate-all: add page_locked assertionsEmilio G. Cota1-3/+79
This is only compiled under CONFIG_DEBUG_TCG to avoid bloating the binary. In user-mode, assert_page_locked is equivalent to assert_mmap_lock. Note: There are some tb_lock assertions left that will be removed by later patches. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Suggested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15translate-all: use per-page locking in !user-modeEmilio G. Cota2-40/+407
Groundwork for supporting parallel TCG generation. Instead of using a global lock (tb_lock) to protect changes to pages, use fine-grained, per-page locks in !user-mode. User-mode stays with mmap_lock. Sometimes changes need to happen atomically on more than one page (e.g. when a TB that spans across two pages is added/invalidated, or when a range of pages is invalidated). We therefore introduce struct page_collection, which helps us keep track of a set of pages that have been locked in the appropriate locking order (i.e. by ascending page index). This commit first introduces the structs and the function helpers, to then convert the calling code to use per-page locking. Note that tb_lock is not removed yet. While at it, rename tb_alloc_page to tb_page_add, which pairs with tb_page_remove. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15translate-all: move tb_invalidate_phys_page_range up in the fileEmilio G. Cota1-38/+39
This greatly simplifies next commit's diff. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15translate-all: work page-by-page in tb_invalidate_phys_range_1Emilio G. Cota1-4/+8
So that we pass a same-page range to tb_invalidate_phys_page_range, instead of always passing an end address that could be on a different page. As discussed with Peter Maydell on the list [1], tb_invalidate_phys_page_range doesn't actually do much with 'end', which explains why we have never hit a bug despite going against what the comment on top of tb_invalidate_phys_page_range requires: > * Invalidate all TBs which intersect with the target physical address range > * [start;end[. NOTE: start and end must refer to the *same* physical page. The appended honours the comment, which avoids confusion. While at it, rework the loop into a for loop, which is less error prone (e.g. "continue" won't result in an infinite loop). [1] https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg09165.html Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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