From 8d04fb55dec381bc5105cb47f29d918e579e8cbd Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Thu, 23 Feb 2017 18:29:11 +0000 Subject: tcg: drop global lock during TCG code execution MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This finally allows TCG to benefit from the iothread introduction: Drop the global mutex while running pure TCG CPU code. Reacquire the lock when entering MMIO or PIO emulation, or when leaving the TCG loop. We have to revert a few optimization for the current TCG threading model, namely kicking the TCG thread in qemu_mutex_lock_iothread and not kicking it in qemu_cpu_kick. We also need to disable RAM block reordering until we have a more efficient locking mechanism at hand. Still, a Linux x86 UP guest and my Musicpal ARM model boot fine here. These numbers demonstrate where we gain something: 20338 jan 20 0 331m 75m 6904 R 99 0.9 0:50.95 qemu-system-arm 20337 jan 20 0 331m 75m 6904 S 20 0.9 0:26.50 qemu-system-arm The guest CPU was fully loaded, but the iothread could still run mostly independent on a second core. Without the patch we don't get beyond 32206 jan 20 0 330m 73m 7036 R 82 0.9 1:06.00 qemu-system-arm 32204 jan 20 0 330m 73m 7036 S 21 0.9 0:17.03 qemu-system-arm We don't benefit significantly, though, when the guest is not fully loading a host CPU. Signed-off-by: Jan Kiszka Message-Id: <1439220437-23957-10-git-send-email-fred.konrad@greensocs.com> [FK: Rebase, fix qemu_devices_reset deadlock, rm address_space_* mutex] Signed-off-by: KONRAD Frederic [EGC: fixed iothread lock for cpu-exec IRQ handling] Signed-off-by: Emilio G. Cota [AJB: -smp single-threaded fix, clean commit msg, BQL fixes] Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Reviewed-by: Pranith Kumar [PM: target-arm changes] Acked-by: Peter Maydell --- target/arm/helper.c | 6 ++++++ target/arm/op_helper.c | 43 +++++++++++++++++++++++++++++++++++++++---- target/i386/smm_helper.c | 7 +++++++ target/s390x/misc_helper.c | 5 ++++- 4 files changed, 56 insertions(+), 5 deletions(-) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index 47250bcf16..753a69d40d 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6769,6 +6769,12 @@ void arm_cpu_do_interrupt(CPUState *cs) arm_cpu_do_interrupt_aarch32(cs); } + /* Hooks may change global state so BQL should be held, also the + * BQL needs to be held for any modification of + * cs->interrupt_request. + */ + g_assert(qemu_mutex_iothread_locked()); + arm_call_el_change_hook(cpu); if (!kvm_enabled()) { diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c index fb366fdc35..5f3e3bdae2 100644 --- a/target/arm/op_helper.c +++ b/target/arm/op_helper.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" #include "qemu/log.h" +#include "qemu/main-loop.h" #include "cpu.h" #include "exec/helper-proto.h" #include "internals.h" @@ -487,7 +488,9 @@ void HELPER(cpsr_write_eret)(CPUARMState *env, uint32_t val) */ env->regs[15] &= (env->thumb ? ~1 : ~3); + qemu_mutex_lock_iothread(); arm_call_el_change_hook(arm_env_get_cpu(env)); + qemu_mutex_unlock_iothread(); } /* Access to user mode registers from privileged modes. */ @@ -735,28 +738,58 @@ void HELPER(set_cp_reg)(CPUARMState *env, void *rip, uint32_t value) { const ARMCPRegInfo *ri = rip; - ri->writefn(env, ri, value); + if (ri->type & ARM_CP_IO) { + qemu_mutex_lock_iothread(); + ri->writefn(env, ri, value); + qemu_mutex_unlock_iothread(); + } else { + ri->writefn(env, ri, value); + } } uint32_t HELPER(get_cp_reg)(CPUARMState *env, void *rip) { const ARMCPRegInfo *ri = rip; + uint32_t res; - return ri->readfn(env, ri); + if (ri->type & ARM_CP_IO) { + qemu_mutex_lock_iothread(); + res = ri->readfn(env, ri); + qemu_mutex_unlock_iothread(); + } else { + res = ri->readfn(env, ri); + } + + return res; } void HELPER(set_cp_reg64)(CPUARMState *env, void *rip, uint64_t value) { const ARMCPRegInfo *ri = rip; - ri->writefn(env, ri, value); + if (ri->type & ARM_CP_IO) { + qemu_mutex_lock_iothread(); + ri->writefn(env, ri, value); + qemu_mutex_unlock_iothread(); + } else { + ri->writefn(env, ri, value); + } } uint64_t HELPER(get_cp_reg64)(CPUARMState *env, void *rip) { const ARMCPRegInfo *ri = rip; + uint64_t res; + + if (ri->type & ARM_CP_IO) { + qemu_mutex_lock_iothread(); + res = ri->readfn(env, ri); + qemu_mutex_unlock_iothread(); + } else { + res = ri->readfn(env, ri); + } - return ri->readfn(env, ri); + return res; } void HELPER(msr_i_pstate)(CPUARMState *env, uint32_t op, uint32_t imm) @@ -989,7 +1022,9 @@ void HELPER(exception_return)(CPUARMState *env) cur_el, new_el, env->pc); } + qemu_mutex_lock_iothread(); arm_call_el_change_hook(arm_env_get_cpu(env)); + qemu_mutex_unlock_iothread(); return; diff --git a/target/i386/smm_helper.c b/target/i386/smm_helper.c index 4dd6a2c544..f051a77c4a 100644 --- a/target/i386/smm_helper.c +++ b/target/i386/smm_helper.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" +#include "qemu/main-loop.h" #include "cpu.h" #include "exec/helper-proto.h" #include "exec/log.h" @@ -42,11 +43,14 @@ void helper_rsm(CPUX86State *env) #define SMM_REVISION_ID 0x00020000 #endif +/* Called with iothread lock taken */ void cpu_smm_update(X86CPU *cpu) { CPUX86State *env = &cpu->env; bool smm_enabled = (env->hflags & HF_SMM_MASK); + g_assert(qemu_mutex_iothread_locked()); + if (cpu->smram) { memory_region_set_enabled(cpu->smram, smm_enabled); } @@ -333,7 +337,10 @@ void helper_rsm(CPUX86State *env) } env->hflags2 &= ~HF2_SMM_INSIDE_NMI_MASK; env->hflags &= ~HF_SMM_MASK; + + qemu_mutex_lock_iothread(); cpu_smm_update(cpu); + qemu_mutex_unlock_iothread(); qemu_log_mask(CPU_LOG_INT, "SMM: after RSM\n"); log_cpu_state_mask(CPU_LOG_INT, CPU(cpu), CPU_DUMP_CCOP); diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c index c9604ea9c7..3cb942e8bb 100644 --- a/target/s390x/misc_helper.c +++ b/target/s390x/misc_helper.c @@ -25,6 +25,7 @@ #include "exec/helper-proto.h" #include "sysemu/kvm.h" #include "qemu/timer.h" +#include "qemu/main-loop.h" #include "exec/address-spaces.h" #ifdef CONFIG_KVM #include @@ -109,11 +110,13 @@ void program_interrupt(CPUS390XState *env, uint32_t code, int ilen) /* SCLP service call */ uint32_t HELPER(servc)(CPUS390XState *env, uint64_t r1, uint64_t r2) { + qemu_mutex_lock_iothread(); int r = sclp_service_call(env, r1, r2); if (r < 0) { program_interrupt(env, -r, 4); - return 0; + r = 0; } + qemu_mutex_unlock_iothread(); return r; } -- cgit v1.2.1