From patchwork Mon Mar 1 18:10:30 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kiszka X-Patchwork-Id: 46582 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id B1D3BB7DA0 for ; Tue, 2 Mar 2010 05:15:20 +1100 (EST) Received: from localhost ([127.0.0.1]:39601 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NmA9E-0006s7-Fv for incoming@patchwork.ozlabs.org; Mon, 01 Mar 2010 13:15:16 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NmA4r-0003Ei-7N for qemu-devel@nongnu.org; Mon, 01 Mar 2010 13:10:45 -0500 Received: from [199.232.76.173] (port=44617 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NmA4o-0003Bs-QC for qemu-devel@nongnu.org; Mon, 01 Mar 2010 13:10:42 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NmA4i-0008Nn-W5 for qemu-devel@nongnu.org; Mon, 01 Mar 2010 13:10:42 -0500 Received: from thoth.sbs.de ([192.35.17.2]:23712) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NmA4h-0008Mp-Gp for qemu-devel@nongnu.org; Mon, 01 Mar 2010 13:10:36 -0500 Received: from mail1.siemens.de (localhost [127.0.0.1]) by thoth.sbs.de (8.12.11.20060308/8.12.11) with ESMTP id o21IAXGY020082; Mon, 1 Mar 2010 19:10:33 +0100 Received: from localhost.localdomain (mchn012c.mchp.siemens.de [139.25.109.167] (may be forged)) by mail1.siemens.de (8.12.11.20060308/8.12.11) with ESMTP id o21IAXST002877; Mon, 1 Mar 2010 19:10:33 +0100 From: Jan Kiszka To: Avi Kivity , Marcelo Tosatti Date: Mon, 1 Mar 2010 19:10:30 +0100 Message-Id: <2257cac7474705fc35d74fcdff0566fb7dc0770e.1267467030.git.jan.kiszka@siemens.com> X-Mailer: git-send-email 1.6.0.2 In-Reply-To: References: In-Reply-To: References: X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.4-2.6 Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org Subject: [Qemu-devel] [PATCH 2/4] KVM: Rework VCPU state writeback API X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This grand cleanup drops all reset and vmsave/load related synchronization points in favor of four(!) generic hooks: - cpu_synchronize_all_states in qemu_savevm_state_complete (initial sync from kernel before vmsave) - cpu_synchronize_all_post_init in qemu_loadvm_state (writeback after vmload) - cpu_synchronize_all_post_init in main after machine init - cpu_synchronize_all_post_reset in qemu_system_reset (writeback after system reset) These writeback points + the existing one of VCPU exec after cpu_synchronize_state map on three levels of writeback: - KVM_PUT_RUNTIME_STATE (during runtime, other VCPUs continue to run) - KVM_PUT_RESET_STATE (on synchronous system reset, all VCPUs stopped) - KVM_PUT_FULL_STATE (on init or vmload, all VCPUs stopped as well) This level is passed to the arch-specific VCPU state writing function that will decide which concrete substates need to be written. That way, no writer of load, save or reset functions that interact with in-kernel KVM states will ever have to worry about synchronization again. That also means that a lot of reasons for races, segfaults and deadlocks are eliminated. cpu_synchronize_state remains untouched, just as Anthony suggested. We continue to need it before reading or writing of VCPU states that are also tracked by in-kernel KVM subsystems. Consequently, this patch removes many cpu_synchronize_state calls that are now redundant, just like remaining explicit register syncs. Signed-off-by: Jan Kiszka --- exec.c | 17 ----------------- hw/apic.c | 2 -- hw/ppc_newworld.c | 3 --- hw/ppc_oldworld.c | 3 --- hw/s390-virtio.c | 1 - kvm-all.c | 19 +++++++++++++------ kvm.h | 25 ++++++++++++++++++++++++- savevm.c | 4 ++++ sysemu.h | 4 ++++ target-i386/kvm.c | 2 +- target-i386/machine.c | 11 ----------- target-ppc/kvm.c | 2 +- target-ppc/machine.c | 4 ---- target-s390x/kvm.c | 3 +-- vl.c | 29 +++++++++++++++++++++++++++++ 15 files changed, 77 insertions(+), 52 deletions(-) diff --git a/exec.c b/exec.c index 8616ff9..50a2e46 100644 --- a/exec.c +++ b/exec.c @@ -518,21 +518,6 @@ void cpu_exec_init_all(unsigned long tb_size) #if defined(CPU_SAVE_VERSION) && !defined(CONFIG_USER_ONLY) -static void cpu_common_pre_save(void *opaque) -{ - CPUState *env = opaque; - - cpu_synchronize_state(env); -} - -static int cpu_common_pre_load(void *opaque) -{ - CPUState *env = opaque; - - cpu_synchronize_state(env); - return 0; -} - static int cpu_common_post_load(void *opaque, int version_id) { CPUState *env = opaque; @@ -550,8 +535,6 @@ static const VMStateDescription vmstate_cpu_common = { .version_id = 1, .minimum_version_id = 1, .minimum_version_id_old = 1, - .pre_save = cpu_common_pre_save, - .pre_load = cpu_common_pre_load, .post_load = cpu_common_post_load, .fields = (VMStateField []) { VMSTATE_UINT32(halted, CPUState), diff --git a/hw/apic.c b/hw/apic.c index 87e7dc0..3c90f4c 100644 --- a/hw/apic.c +++ b/hw/apic.c @@ -938,8 +938,6 @@ static void apic_reset(void *opaque) APICState *s = opaque; int bsp; - cpu_synchronize_state(s->cpu_env); - bsp = cpu_is_bsp(s->cpu_env); s->apicbase = 0xfee00000 | (bsp ? MSR_IA32_APICBASE_BSP : 0) | MSR_IA32_APICBASE_ENABLE; diff --git a/hw/ppc_newworld.c b/hw/ppc_newworld.c index bc86c85..d4f9013 100644 --- a/hw/ppc_newworld.c +++ b/hw/ppc_newworld.c @@ -167,9 +167,6 @@ static void ppc_core99_init (ram_addr_t ram_size, envs[i] = env; } - /* Make sure all register sets take effect */ - cpu_synchronize_state(env); - /* allocate RAM */ ram_offset = qemu_ram_alloc(ram_size); cpu_register_physical_memory(0, ram_size, ram_offset); diff --git a/hw/ppc_oldworld.c b/hw/ppc_oldworld.c index 04a7835..93c95ba 100644 --- a/hw/ppc_oldworld.c +++ b/hw/ppc_oldworld.c @@ -165,9 +165,6 @@ static void ppc_heathrow_init (ram_addr_t ram_size, envs[i] = env; } - /* Make sure all register sets take effect */ - cpu_synchronize_state(env); - /* allocate RAM */ if (ram_size > (2047 << 20)) { fprintf(stderr, diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c index 3582728..ad3386f 100644 --- a/hw/s390-virtio.c +++ b/hw/s390-virtio.c @@ -185,7 +185,6 @@ static void s390_init(ram_addr_t ram_size, exit(1); } - cpu_synchronize_state(env); env->psw.addr = KERN_IMAGE_START; env->psw.mask = 0x0000000180000000ULL; } diff --git a/kvm-all.c b/kvm-all.c index 2f7e33a..534ead0 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -156,10 +156,6 @@ static void kvm_reset_vcpu(void *opaque) CPUState *env = opaque; kvm_arch_reset_vcpu(env); - if (kvm_arch_put_registers(env)) { - fprintf(stderr, "Fatal: kvm vcpu reset failed\n"); - abort(); - } } int kvm_irqchip_in_kernel(void) @@ -214,7 +210,6 @@ int kvm_init_vcpu(CPUState *env) if (ret == 0) { qemu_register_reset(kvm_reset_vcpu, env); kvm_arch_reset_vcpu(env); - ret = kvm_arch_put_registers(env); } err: return ret; @@ -753,6 +748,18 @@ void kvm_cpu_synchronize_state(CPUState *env) } } +void kvm_cpu_synchronize_post_reset(CPUState *env) +{ + kvm_arch_put_registers(env, KVM_PUT_RESET_STATE); + env->kvm_vcpu_dirty = 0; +} + +void kvm_cpu_synchronize_post_init(CPUState *env) +{ + kvm_arch_put_registers(env, KVM_PUT_FULL_STATE); + env->kvm_vcpu_dirty = 0; +} + int kvm_cpu_exec(CPUState *env) { struct kvm_run *run = env->kvm_run; @@ -770,7 +777,7 @@ int kvm_cpu_exec(CPUState *env) #endif if (env->kvm_vcpu_dirty) { - kvm_arch_put_registers(env); + kvm_arch_put_registers(env, KVM_PUT_RUNTIME_STATE); env->kvm_vcpu_dirty = 0; } diff --git a/kvm.h b/kvm.h index a602e45..b2937b9 100644 --- a/kvm.h +++ b/kvm.h @@ -82,7 +82,14 @@ int kvm_arch_pre_run(CPUState *env, struct kvm_run *run); int kvm_arch_get_registers(CPUState *env); -int kvm_arch_put_registers(CPUState *env); +/* state subset only touched by the VCPU itself during runtime */ +#define KVM_PUT_RUNTIME_STATE 1 +/* state subset modified during VCPU reset */ +#define KVM_PUT_RESET_STATE 2 +/* full state set, modified during initialization or on vmload */ +#define KVM_PUT_FULL_STATE 3 + +int kvm_arch_put_registers(CPUState *env, int level); int kvm_arch_init(KVMState *s, int smp_cpus); @@ -126,6 +133,8 @@ int kvm_check_extension(KVMState *s, unsigned int extension); uint32_t kvm_arch_get_supported_cpuid(CPUState *env, uint32_t function, int reg); void kvm_cpu_synchronize_state(CPUState *env); +void kvm_cpu_synchronize_post_reset(CPUState *env); +void kvm_cpu_synchronize_post_init(CPUState *env); /* generic hooks - to be moved/refactored once there are more users */ @@ -136,4 +145,18 @@ static inline void cpu_synchronize_state(CPUState *env) } } +static inline void cpu_synchronize_post_reset(CPUState *env) +{ + if (kvm_enabled()) { + kvm_cpu_synchronize_post_reset(env); + } +} + +static inline void cpu_synchronize_post_init(CPUState *env) +{ + if (kvm_enabled()) { + kvm_cpu_synchronize_post_init(env); + } +} + #endif diff --git a/savevm.c b/savevm.c index 4b58663..a6e774b 100644 --- a/savevm.c +++ b/savevm.c @@ -1345,6 +1345,8 @@ int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f) { SaveStateEntry *se; + cpu_synchronize_all_states(); + QTAILQ_FOREACH(se, &savevm_handlers, entry) { if (se->save_live_state == NULL) continue; @@ -1545,6 +1547,8 @@ int qemu_loadvm_state(QEMUFile *f) } } + cpu_synchronize_all_post_init(); + ret = 0; out: diff --git a/sysemu.h b/sysemu.h index 8ba618e..d77344c 100644 --- a/sysemu.h +++ b/sysemu.h @@ -58,6 +58,10 @@ int load_vmstate(Monitor *mon, const char *name); void do_delvm(Monitor *mon, const QDict *qdict); void do_info_snapshots(Monitor *mon); +void cpu_synchronize_all_states(void); +void cpu_synchronize_all_post_reset(void); +void cpu_synchronize_all_post_init(void); + void qemu_announce_self(void); void main_loop_wait(int timeout); diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 2365ca3..a4767b2 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -882,7 +882,7 @@ static int kvm_guest_debug_workarounds(CPUState *env) return ret; } -int kvm_arch_put_registers(CPUState *env) +int kvm_arch_put_registers(CPUState *env, int level) { int ret; diff --git a/target-i386/machine.c b/target-i386/machine.c index 8770491..b547e2a 100644 --- a/target-i386/machine.c +++ b/target-i386/machine.c @@ -321,8 +321,6 @@ static void cpu_pre_save(void *opaque) CPUState *env = opaque; int i; - cpu_synchronize_state(env); - /* FPU */ env->fpus_vmstate = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11; env->fptag_vmstate = 0; @@ -337,14 +335,6 @@ static void cpu_pre_save(void *opaque) #endif } -static int cpu_pre_load(void *opaque) -{ - CPUState *env = opaque; - - cpu_synchronize_state(env); - return 0; -} - static int cpu_post_load(void *opaque, int version_id) { CPUState *env = opaque; @@ -373,7 +363,6 @@ static const VMStateDescription vmstate_cpu = { .minimum_version_id = 3, .minimum_version_id_old = 3, .pre_save = cpu_pre_save, - .pre_load = cpu_pre_load, .post_load = cpu_post_load, .fields = (VMStateField []) { VMSTATE_UINTTL_ARRAY(regs, CPUState, CPU_NB_REGS), diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index 8ad0037..aa3d432 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -73,7 +73,7 @@ void kvm_arch_reset_vcpu(CPUState *env) { } -int kvm_arch_put_registers(CPUState *env) +int kvm_arch_put_registers(CPUState *env, int level) { struct kvm_regs regs; int ret; diff --git a/target-ppc/machine.c b/target-ppc/machine.c index 4897c8a..67de951 100644 --- a/target-ppc/machine.c +++ b/target-ppc/machine.c @@ -7,8 +7,6 @@ void cpu_save(QEMUFile *f, void *opaque) CPUState *env = (CPUState *)opaque; unsigned int i, j; - cpu_synchronize_state(env); - for (i = 0; i < 32; i++) qemu_put_betls(f, &env->gpr[i]); #if !defined(TARGET_PPC64) @@ -96,8 +94,6 @@ int cpu_load(QEMUFile *f, void *opaque, int version_id) CPUState *env = (CPUState *)opaque; unsigned int i, j; - cpu_synchronize_state(env); - for (i = 0; i < 32; i++) qemu_get_betls(f, &env->gpr[i]); #if !defined(TARGET_PPC64) diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c index 0199a65..72e77b0 100644 --- a/target-s390x/kvm.c +++ b/target-s390x/kvm.c @@ -91,7 +91,7 @@ void kvm_arch_reset_vcpu(CPUState *env) /* FIXME: add code to reset vcpu. */ } -int kvm_arch_put_registers(CPUState *env) +int kvm_arch_put_registers(CPUState *env, int level) { struct kvm_regs regs; int ret; @@ -296,7 +296,6 @@ static int handle_hypercall(CPUState *env, struct kvm_run *run) cpu_synchronize_state(env); r = s390_virtio_hypercall(env); - kvm_arch_put_registers(env); return r; } diff --git a/vl.c b/vl.c index 66e477a..67143a7 100644 --- a/vl.c +++ b/vl.c @@ -3002,6 +3002,33 @@ static void nographic_update(void *opaque) qemu_mod_timer(nographic_timer, interval + qemu_get_clock(rt_clock)); } +void cpu_synchronize_all_states(void) +{ + CPUState *cpu; + + for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) { + cpu_synchronize_state(cpu); + } +} + +void cpu_synchronize_all_post_reset(void) +{ + CPUState *cpu; + + for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) { + cpu_synchronize_post_reset(cpu); + } +} + +void cpu_synchronize_all_post_init(void) +{ + CPUState *cpu; + + for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) { + cpu_synchronize_post_init(cpu); + } +} + struct vm_change_state_entry { VMChangeStateHandler *cb; void *opaque; @@ -3143,6 +3170,7 @@ void qemu_system_reset(void) QTAILQ_FOREACH_SAFE(re, &reset_handlers, entry, nre) { re->func(re->opaque); } + cpu_synchronize_all_post_reset(); } void qemu_system_reset_request(void) @@ -5927,6 +5955,7 @@ int main(int argc, char **argv, char **envp) machine->init(ram_size, boot_devices, kernel_filename, kernel_cmdline, initrd_filename, cpu_model); + cpu_synchronize_all_post_init(); #ifndef _WIN32 /* must be after terminal init, SDL library changes signal handlers */