* [questions] savevm|loadvm @ 2010-03-30 5:59 ` Wenhao Xu 0 siblings, 0 replies; 17+ messages in thread From: Wenhao Xu @ 2010-03-30 5:59 UTC (permalink / raw) To: qemu-devel, kvm [-- Attachment #1: Type: text/plain, Size: 390 bytes --] Hi, all, I am working with switching QEMU from running in KVM mode to QEMU emulatoin mode dynamically. Intuitively, if the snapshot created using savevm in kvm mode can be used by the loadvm command in QEMU emulator mode, the switchment could makes use of this. I tried to do so. However, it does not work. Any idea how to fix it? Thanks for the help. regards, Wenhao -- ~_~ [-- Attachment #2: Type: text/html, Size: 440 bytes --] ^ permalink raw reply [flat|nested] 17+ messages in thread
* [Qemu-devel] [questions] savevm|loadvm @ 2010-03-30 5:59 ` Wenhao Xu 0 siblings, 0 replies; 17+ messages in thread From: Wenhao Xu @ 2010-03-30 5:59 UTC (permalink / raw) To: qemu-devel, kvm [-- Attachment #1: Type: text/plain, Size: 390 bytes --] Hi, all, I am working with switching QEMU from running in KVM mode to QEMU emulatoin mode dynamically. Intuitively, if the snapshot created using savevm in kvm mode can be used by the loadvm command in QEMU emulator mode, the switchment could makes use of this. I tried to do so. However, it does not work. Any idea how to fix it? Thanks for the help. regards, Wenhao -- ~_~ [-- Attachment #2: Type: text/html, Size: 440 bytes --] ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [questions] savevm|loadvm 2010-03-30 5:59 ` [Qemu-devel] " Wenhao Xu @ 2010-03-30 8:22 ` Juan Quintela -1 siblings, 0 replies; 17+ messages in thread From: Juan Quintela @ 2010-03-30 8:22 UTC (permalink / raw) To: Wenhao Xu; +Cc: qemu-devel, kvm [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #1: Type: text/plain; charset=us-ascii, Size: 866 bytes --] Wenhao Xu <xuwenhao2008@gmail.com> wrote: > Hi, all, > ¿ï½ I am working with switching QEMU from running in KVM mode to QEMU > emulatoin mode dynamically. > ¿ï½ Intuitively, if the snapshot created using savevm in kvm mode can be > used by the loadvm command in QEMU emulator mode, the switchment could > makes use of this.¿ I tried to do so. However, it does not work.¿ Any idea > how to fix it? > ¿ï½¿ Thanks for the help. kvm uses a different memory layout (slots in qemu/kvm lingo), that means that memory can't be migrated (that is a big problem). Once that is "fixed", you need to work on the several in-kernel chips that don't exist in qemu (kvm-irq-chip and the like). Once that is fixed, you can look for what more things are broken. Once here, why do you want to do that switch? Later, Juan. > regards, > Wenhao > > -- > ~_~ ^ permalink raw reply [flat|nested] 17+ messages in thread
* [Qemu-devel] Re: [questions] savevm|loadvm @ 2010-03-30 8:22 ` Juan Quintela 0 siblings, 0 replies; 17+ messages in thread From: Juan Quintela @ 2010-03-30 8:22 UTC (permalink / raw) To: Wenhao Xu; +Cc: qemu-devel, kvm [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #1: Type: text/plain; charset=us-ascii, Size: 866 bytes --] Wenhao Xu <xuwenhao2008@gmail.com> wrote: > Hi, all, > ¿ï½ I am working with switching QEMU from running in KVM mode to QEMU > emulatoin mode dynamically. > ¿ï½ Intuitively, if the snapshot created using savevm in kvm mode can be > used by the loadvm command in QEMU emulator mode, the switchment could > makes use of this.¿ I tried to do so. However, it does not work.¿ Any idea > how to fix it? > ¿ï½¿ Thanks for the help. kvm uses a different memory layout (slots in qemu/kvm lingo), that means that memory can't be migrated (that is a big problem). Once that is "fixed", you need to work on the several in-kernel chips that don't exist in qemu (kvm-irq-chip and the like). Once that is fixed, you can look for what more things are broken. Once here, why do you want to do that switch? Later, Juan. > regards, > Wenhao > > -- > ~_~ ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [questions] savevm|loadvm 2010-03-30 8:22 ` [Qemu-devel] " Juan Quintela @ 2010-03-30 17:03 ` Wenhao Xu -1 siblings, 0 replies; 17+ messages in thread From: Wenhao Xu @ 2010-03-30 17:03 UTC (permalink / raw) To: Juan Quintela; +Cc: qemu-devel, kvm Hi, Juan, I am fresh to both QEMU and KVM. But so far, I notice that QEMU uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can use and uses cpu_register_physical_memory_offset to register the same memory to QEMU emulator, which means QEMU and KVM use the same host virtual memory. And therefore the memory KVM modified could be directly reflected to QEMU. I don't quite understand the different memory layout problem between the two. So I don't know exactly what you mean to "fix" it? For why switching is useful? Actually, I am a master student now and doing a course project. What am I arguing is that QEMU could be potentially useful to do many instrumentation analysis, but it is a bit slow. So by combing with KVM, when the os runs to some place where we are interested in, switch it to QEMU emulator mode and do the analysis and then switch back. FYI, there is a paper doing so in Xen, "Practical taint-based protection using demand emulation". I want to do the same "demand emulation" for KVM. I am trying to patch some code. When kvm_run returns, I tried to synchronize the CPU state and memory dirty map, and then run into QEMU emulator mode. However, I got an error, "qemu: fatal: invalid tss type". I don't know exactly where is the problem. Thanks for helping me working this out. I am really stuck into this problem. regards, Wenhao On Tue, Mar 30, 2010 at 1:22 AM, Juan Quintela <quintela@redhat.com> wrote: > Wenhao Xu <xuwenhao2008@gmail.com> wrote: >> Hi, all, >> żď˝ I am working with switching QEMU from running in KVM mode to QEMU >> emulatoin mode dynamically. >> żď˝ Intuitively, if the snapshot created using savevm in kvm mode can be >> used by the loadvm command in QEMU emulator mode, the switchment could >> makes use of this.ż I tried to do so. However, it does not work.ż Any idea >> how to fix it? >> żď˝ż Thanks for the help. > > kvm uses a different memory layout (slots in qemu/kvm lingo), that means > that memory can't be migrated (that is a big problem). Once that is > "fixed", you need to work on the several in-kernel chips that don't > exist in qemu (kvm-irq-chip and the like). Once that is fixed, you can > look for what more things are broken. > > Once here, why do you want to do that switch? > > Later, Juan. > >> regards, >> Wenhao >> >> -- >> ~_~ > -- ~_~ ^ permalink raw reply [flat|nested] 17+ messages in thread
* [Qemu-devel] Re: [questions] savevm|loadvm @ 2010-03-30 17:03 ` Wenhao Xu 0 siblings, 0 replies; 17+ messages in thread From: Wenhao Xu @ 2010-03-30 17:03 UTC (permalink / raw) To: Juan Quintela; +Cc: qemu-devel, kvm Hi, Juan, I am fresh to both QEMU and KVM. But so far, I notice that QEMU uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can use and uses cpu_register_physical_memory_offset to register the same memory to QEMU emulator, which means QEMU and KVM use the same host virtual memory. And therefore the memory KVM modified could be directly reflected to QEMU. I don't quite understand the different memory layout problem between the two. So I don't know exactly what you mean to "fix" it? For why switching is useful? Actually, I am a master student now and doing a course project. What am I arguing is that QEMU could be potentially useful to do many instrumentation analysis, but it is a bit slow. So by combing with KVM, when the os runs to some place where we are interested in, switch it to QEMU emulator mode and do the analysis and then switch back. FYI, there is a paper doing so in Xen, "Practical taint-based protection using demand emulation". I want to do the same "demand emulation" for KVM. I am trying to patch some code. When kvm_run returns, I tried to synchronize the CPU state and memory dirty map, and then run into QEMU emulator mode. However, I got an error, "qemu: fatal: invalid tss type". I don't know exactly where is the problem. Thanks for helping me working this out. I am really stuck into this problem. regards, Wenhao On Tue, Mar 30, 2010 at 1:22 AM, Juan Quintela <quintela@redhat.com> wrote: > Wenhao Xu <xuwenhao2008@gmail.com> wrote: >> Hi, all, >> żď˝ I am working with switching QEMU from running in KVM mode to QEMU >> emulatoin mode dynamically. >> żď˝ Intuitively, if the snapshot created using savevm in kvm mode can be >> used by the loadvm command in QEMU emulator mode, the switchment could >> makes use of this.ż I tried to do so. However, it does not work.ż Any idea >> how to fix it? >> żď˝ż Thanks for the help. > > kvm uses a different memory layout (slots in qemu/kvm lingo), that means > that memory can't be migrated (that is a big problem). Once that is > "fixed", you need to work on the several in-kernel chips that don't > exist in qemu (kvm-irq-chip and the like). Once that is fixed, you can > look for what more things are broken. > > Once here, why do you want to do that switch? > > Later, Juan. > >> regards, >> Wenhao >> >> -- >> ~_~ > -- ~_~ ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [questions] savevm|loadvm 2010-03-30 17:03 ` [Qemu-devel] " Wenhao Xu @ 2010-03-31 11:31 ` Juan Quintela -1 siblings, 0 replies; 17+ messages in thread From: Juan Quintela @ 2010-03-31 11:31 UTC (permalink / raw) To: Wenhao Xu; +Cc: qemu-devel, kvm Wenhao Xu <xuwenhao2008@gmail.com> wrote: > Hi, Juan, > I am fresh to both QEMU and KVM. But so far, I notice that QEMU > uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can > use and uses cpu_register_physical_memory_offset to register the same > memory to QEMU emulator, which means QEMU and KVM use the same host > virtual memory. And therefore the memory KVM modified could be > directly reflected to QEMU. I don't quite understand the different > memory layout problem between the two. So I don't know exactly what > you mean to "fix" it? 1st. qemu-kvm.git and qemu.git memory layouts are different, indeed with qemu.git kvm mode. (yes it is complex and weird). kvm vs qemu initialization is different. Expecting to stop kvm, and run tcg from there is not going to work. I guess it would need a lot of changes, but I haven't looked at it myself. > For why switching is useful? Actually, I am a master student now > and doing a course project. What am I arguing is that QEMU could be > potentially useful to do many instrumentation analysis, but it is a > bit slow. So by combing with KVM, when the os runs to some place where > we are interested in, switch it to QEMU emulator mode and do the > analysis and then switch back. idea is good, but I don't think that it is _so_ easy at this point. tcg and kvm basically live in a different world. Not sure of what needs to be done to make them back on sync. > FYI, there is a paper doing so in Xen, "Practical taint-based > protection using demand emulation". I want to do the same "demand > emulation" for KVM. > > I am trying to patch some code. When kvm_run returns, I tried to > synchronize the CPU state and memory dirty map, and then run into QEMU > emulator mode. However, I got an error, "qemu: fatal: invalid tss > type". I don't know exactly where is the problem. I guess you need to look at tcg startup, and see how it initializes vcpus, and hack something around that when you try to run tcg at kvm_run exit. Have Fun :) Later, Juan. ^ permalink raw reply [flat|nested] 17+ messages in thread
* [Qemu-devel] Re: [questions] savevm|loadvm @ 2010-03-31 11:31 ` Juan Quintela 0 siblings, 0 replies; 17+ messages in thread From: Juan Quintela @ 2010-03-31 11:31 UTC (permalink / raw) To: Wenhao Xu; +Cc: qemu-devel, kvm Wenhao Xu <xuwenhao2008@gmail.com> wrote: > Hi, Juan, > I am fresh to both QEMU and KVM. But so far, I notice that QEMU > uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can > use and uses cpu_register_physical_memory_offset to register the same > memory to QEMU emulator, which means QEMU and KVM use the same host > virtual memory. And therefore the memory KVM modified could be > directly reflected to QEMU. I don't quite understand the different > memory layout problem between the two. So I don't know exactly what > you mean to "fix" it? 1st. qemu-kvm.git and qemu.git memory layouts are different, indeed with qemu.git kvm mode. (yes it is complex and weird). kvm vs qemu initialization is different. Expecting to stop kvm, and run tcg from there is not going to work. I guess it would need a lot of changes, but I haven't looked at it myself. > For why switching is useful? Actually, I am a master student now > and doing a course project. What am I arguing is that QEMU could be > potentially useful to do many instrumentation analysis, but it is a > bit slow. So by combing with KVM, when the os runs to some place where > we are interested in, switch it to QEMU emulator mode and do the > analysis and then switch back. idea is good, but I don't think that it is _so_ easy at this point. tcg and kvm basically live in a different world. Not sure of what needs to be done to make them back on sync. > FYI, there is a paper doing so in Xen, "Practical taint-based > protection using demand emulation". I want to do the same "demand > emulation" for KVM. > > I am trying to patch some code. When kvm_run returns, I tried to > synchronize the CPU state and memory dirty map, and then run into QEMU > emulator mode. However, I got an error, "qemu: fatal: invalid tss > type". I don't know exactly where is the problem. I guess you need to look at tcg startup, and see how it initializes vcpus, and hack something around that when you try to run tcg at kvm_run exit. Have Fun :) Later, Juan. ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [questions] savevm|loadvm 2010-03-31 11:31 ` [Qemu-devel] " Juan Quintela @ 2010-04-01 8:42 ` Avi Kivity -1 siblings, 0 replies; 17+ messages in thread From: Avi Kivity @ 2010-04-01 8:42 UTC (permalink / raw) To: Juan Quintela; +Cc: Wenhao Xu, qemu-devel, kvm On 03/31/2010 02:31 PM, Juan Quintela wrote: > Wenhao Xu<xuwenhao2008@gmail.com> wrote: > >> Hi, Juan, >> I am fresh to both QEMU and KVM. But so far, I notice that QEMU >> uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can >> use and uses cpu_register_physical_memory_offset to register the same >> memory to QEMU emulator, which means QEMU and KVM use the same host >> virtual memory. And therefore the memory KVM modified could be >> directly reflected to QEMU. I don't quite understand the different >> memory layout problem between the two. So I don't know exactly what >> you mean to "fix" it? >> > 1st. qemu-kvm.git and qemu.git memory layouts are different, indeed with > qemu.git kvm mode. (yes it is complex and weird). > > kvm vs qemu initialization is different. Expecting to stop kvm, and run > tcg from there is not going to work. I guess it would need a lot of > changes, but I haven't looked at it myself. > I don't think it's so far fetched. In fact early versions of qemu-kvm switched between emulation and virtualization (emulate until 64-bit mode, also emulate mmio instructions in qemu). Even today, all memory initialization is done via generic qemu mechanisms. So long as you synchronize all state (pit, irqchip, registers) you should be fine. >> For why switching is useful? Actually, I am a master student now >> and doing a course project. What am I arguing is that QEMU could be >> potentially useful to do many instrumentation analysis, but it is a >> bit slow. So by combing with KVM, when the os runs to some place where >> we are interested in, switch it to QEMU emulator mode and do the >> analysis and then switch back. >> > idea is good, but I don't think that it is _so_ easy at this point. tcg > and kvm basically live in a different world. Not sure of what needs to > be done to make them back on sync. > cpu_synchronize_state() -- error compiling committee.c: too many arguments to function ^ permalink raw reply [flat|nested] 17+ messages in thread
* [Qemu-devel] Re: [questions] savevm|loadvm @ 2010-04-01 8:42 ` Avi Kivity 0 siblings, 0 replies; 17+ messages in thread From: Avi Kivity @ 2010-04-01 8:42 UTC (permalink / raw) To: Juan Quintela; +Cc: Wenhao Xu, qemu-devel, kvm On 03/31/2010 02:31 PM, Juan Quintela wrote: > Wenhao Xu<xuwenhao2008@gmail.com> wrote: > >> Hi, Juan, >> I am fresh to both QEMU and KVM. But so far, I notice that QEMU >> uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can >> use and uses cpu_register_physical_memory_offset to register the same >> memory to QEMU emulator, which means QEMU and KVM use the same host >> virtual memory. And therefore the memory KVM modified could be >> directly reflected to QEMU. I don't quite understand the different >> memory layout problem between the two. So I don't know exactly what >> you mean to "fix" it? >> > 1st. qemu-kvm.git and qemu.git memory layouts are different, indeed with > qemu.git kvm mode. (yes it is complex and weird). > > kvm vs qemu initialization is different. Expecting to stop kvm, and run > tcg from there is not going to work. I guess it would need a lot of > changes, but I haven't looked at it myself. > I don't think it's so far fetched. In fact early versions of qemu-kvm switched between emulation and virtualization (emulate until 64-bit mode, also emulate mmio instructions in qemu). Even today, all memory initialization is done via generic qemu mechanisms. So long as you synchronize all state (pit, irqchip, registers) you should be fine. >> For why switching is useful? Actually, I am a master student now >> and doing a course project. What am I arguing is that QEMU could be >> potentially useful to do many instrumentation analysis, but it is a >> bit slow. So by combing with KVM, when the os runs to some place where >> we are interested in, switch it to QEMU emulator mode and do the >> analysis and then switch back. >> > idea is good, but I don't think that it is _so_ easy at this point. tcg > and kvm basically live in a different world. Not sure of what needs to > be done to make them back on sync. > cpu_synchronize_state() -- error compiling committee.c: too many arguments to function ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [questions] savevm|loadvm 2010-04-01 8:42 ` [Qemu-devel] " Avi Kivity @ 2010-04-01 19:35 ` Wenhao Xu -1 siblings, 0 replies; 17+ messages in thread From: Wenhao Xu @ 2010-04-01 19:35 UTC (permalink / raw) To: Avi Kivity; +Cc: Juan Quintela, qemu-devel, kvm, aliguori, paul Does current qemu-kvm (qemu v0.12.3) use the irqchip, pit of KVM? I cannot find any KVM_CREATE_IRQCHIP and KVM_CREATE_PIT in the qemu code. Concerning the interface between qemu and kvm, I have the following confusion: 1. How irqchip and pit of KVM collaborating with the irq and pit emulation of QEMU? As far as I see, qemu-kvm still uses qemu's irq and pit emulation, doesn't it? 2. For return from KVM to QEMU, I cannot get the meaning of two exit reasons: case KVM_EXIT_EXCEPTION: What exception will cause KVM exit? default: dprintf("kvm_arch_handle_exit\n"); ret = kvm_arch_handle_exit(env, run); What exit reasons are default? 3. How could DMA interrupt the cpu when it finishes and the qemu-kvm is still running in kvm now? I am still working in the patch, but these confusions really prevent me moving forward. Thanks first for you guys giving me more hints. The following is the code so far I write: The main idea is synchronizing the CPU state and enter into the emulator mode when switching from kvm to emulator. I only do the switch when the exit reason is KVM_EXIT_IRQ_WINDOW_OPEN. However, I got the following errors: Whenever switch from kvm to qemu, the interrupt request in qemu will cause qemu enter into smm mode which is definitely a bug. This is the code that tries to synchronize the CPU state when the IRQ Window is open. And then tries to switch back to the QEMU emulator mode. --- qemu-0.12.3/kvm-all.c 2010-02-23 12:54:38.000000000 -0800 +++ de-0.12.3/kvm-all.c 2010-04-01 12:23:07.000000000 -0700 @@ -577,7 +577,6 @@ { struct kvm_run *run = env->kvm_run; int ret; - dprintf("kvm_cpu_exec()\n"); do { @@ -641,7 +640,8 @@ dprintf("kvm_exit_unknown\n"); break; case KVM_EXIT_FAIL_ENTRY: - dprintf("kvm_exit_fail_entry\n"); + printf("kvm_exit_fail_entry\n"); + exit(1); break; case KVM_EXIT_EXCEPTION: dprintf("kvm_exit_exception\n"); @@ -670,7 +670,31 @@ env->exit_request = 0; env->exception_index = EXCP_INTERRUPT; } - + + /* de, start emulation */ + if(env->ask_for_emulation){ + //if( (env->eflags & IF_MASK) && (run->ready_for_interrupt_injection)){ + if(run->exit_reason == KVM_EXIT_IRQ_WINDOW_OPEN ){ + int saved_vm_running = vm_running; + vm_stop(0); + if (kvm_arch_get_registers(env)) { + printf("Fatal: kvm vcpu get registers failed\n"); + abort(); + } + env->kvm_state->regs_modified = 1; + env->is_in_emulation = 1; + target_ulong pc_start = env->segs[R_CS].base + env->eip; + /* int flags = env->hflags |(env->eflags & (IOPL_MASK | TF_MASK | RF_MASK | VM_MASK)); */ + /* int code32 = !((flags >> HF_CS32_SHIFT) & 1); */ + printf("start emulation at pc: 0x%x, eip:0x%x\n", pc_start, env->eip); + /* target_disas(stderr, pc_start, 10, code32); */ + /* env->interrupt_request = 0; */ + printf("tr type:%d\n", (env->tr.flags >> DESC_TYPE_SHIFT) & 0xf); + + if(saved_vm_running) + vm_start(); + } + } return ret; } ask_for_emulation is in the CPU_COMMON --- qemu-0.12.3/cpu-defs.h 2010-02-23 12:54:38.000000000 -0800 +++ de-0.12.3/cpu-defs.h 2010-03-28 15:17:14.000000000 -0700 @@ -197,6 +197,8 @@ const char *cpu_model_str; \ struct KVMState *kvm_state; \ struct kvm_run *kvm_run; \ - int kvm_fd; + int kvm_fd; \ + int ask_for_emulation; /* ask for emulation if 1 */ \ + int is_in_emulation; /* is in emulation */ when is_in_emulation, don't enter kvm again in cpu_exec --- qemu-0.12.3/cpu-exec.c 2010-02-23 12:54:38.000000000 -0800 +++ de-0.12.3/cpu-exec.c 2010-03-30 00:38:01.000000000 -0700 #if defined(TARGET_I386) - if (!kvm_enabled()) { - /* put eflags in CPU temporary format */ - CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); - DF = 1 - (2 * ((env->eflags >> 10) & 1)); - CC_OP = CC_OP_EFLAGS; - env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); - } + if (!kvm_enabled() || env->is_in_emulation) { + /* put eflags in CPU temporary format */ + CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); + DF = 1 - (2 * ((env->eflags >> 10) & 1)); + CC_OP = CC_OP_EFLAGS; + env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); + } - if (kvm_enabled()) { - kvm_cpu_exec(env); - longjmp(env->jmp_env, 1); - } + if (kvm_enabled() && !env->is_in_emulation) { + kvm_cpu_exec(env); + longjmp(env->jmp_env, 1); + } command "start_emulation", "stop_emulation" support in the monitor --- qemu-0.12.3/monitor.c 2010-02-23 12:54:38.000000000 -0800 +++ de-0.12.3/monitor.c 2010-03-28 15:16:18.000000000 -0700 @@ -56,6 +56,9 @@ #include "json-streamer.h" #include "json-parser.h" #include "osdep.h" +/* de */ +static void do_start_emulation(Monitor *mon, const QDict *qdict, QObject **ret_data) +{ + CPUState *env = mon_get_cpu(); + env->ask_for_emulation = 1; + monitor_printf(mon, "Starting emulation...\n"); +} + +static void do_stop_emulation(Monitor *mon, const QDict *qdict, QObject **ret_data) +{ + CPUState *env = mon_get_cpu(); + env->ask_for_emulation = 0; + monitor_printf(mon, "Stop emulation\n"); +} + +static void do_is_emulation(Monitor *mon, const QDict *qdict, QObject **ret_data) +{ + CPUState *env = mon_get_cpu(); + if(env->is_in_emulation) + monitor_printf(mon, "Emulating now\n"); + else + monitor_printf(mon, "Virtualizing now\n"); +} + Thanks for the help, guys. I appreciate for your time to help! regards, Wenhao On Thu, Apr 1, 2010 at 1:42 AM, Avi Kivity <avi@redhat.com> wrote: > On 03/31/2010 02:31 PM, Juan Quintela wrote: >> >> Wenhao Xu<xuwenhao2008@gmail.com> wrote: >> >>> >>> Hi, Juan, >>> I am fresh to both QEMU and KVM. But so far, I notice that QEMU >>> uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can >>> use and uses cpu_register_physical_memory_offset to register the same >>> memory to QEMU emulator, which means QEMU and KVM use the same host >>> virtual memory. And therefore the memory KVM modified could be >>> directly reflected to QEMU. I don't quite understand the different >>> memory layout problem between the two. So I don't know exactly what >>> you mean to "fix" it? >>> >> >> 1st. qemu-kvm.git and qemu.git memory layouts are different, indeed with >> qemu.git kvm mode. (yes it is complex and weird). >> >> kvm vs qemu initialization is different. Expecting to stop kvm, and run >> tcg from there is not going to work. I guess it would need a lot of >> changes, but I haven't looked at it myself. >> > > I don't think it's so far fetched. In fact early versions of qemu-kvm > switched between emulation and virtualization (emulate until 64-bit mode, > also emulate mmio instructions in qemu). > > Even today, all memory initialization is done via generic qemu mechanisms. > So long as you synchronize all state (pit, irqchip, registers) you should > be fine. > >>> For why switching is useful? Actually, I am a master student now >>> and doing a course project. What am I arguing is that QEMU could be >>> potentially useful to do many instrumentation analysis, but it is a >>> bit slow. So by combing with KVM, when the os runs to some place where >>> we are interested in, switch it to QEMU emulator mode and do the >>> analysis and then switch back. >>> >> >> idea is good, but I don't think that it is _so_ easy at this point. tcg >> and kvm basically live in a different world. Not sure of what needs to >> be done to make them back on sync. >> > > cpu_synchronize_state() > > -- > error compiling committee.c: too many arguments to function > > -- ~_~ ^ permalink raw reply [flat|nested] 17+ messages in thread
* [Qemu-devel] Re: [questions] savevm|loadvm @ 2010-04-01 19:35 ` Wenhao Xu 0 siblings, 0 replies; 17+ messages in thread From: Wenhao Xu @ 2010-04-01 19:35 UTC (permalink / raw) To: Avi Kivity; +Cc: aliguori, paul, qemu-devel, kvm, Juan Quintela Does current qemu-kvm (qemu v0.12.3) use the irqchip, pit of KVM? I cannot find any KVM_CREATE_IRQCHIP and KVM_CREATE_PIT in the qemu code. Concerning the interface between qemu and kvm, I have the following confusion: 1. How irqchip and pit of KVM collaborating with the irq and pit emulation of QEMU? As far as I see, qemu-kvm still uses qemu's irq and pit emulation, doesn't it? 2. For return from KVM to QEMU, I cannot get the meaning of two exit reasons: case KVM_EXIT_EXCEPTION: What exception will cause KVM exit? default: dprintf("kvm_arch_handle_exit\n"); ret = kvm_arch_handle_exit(env, run); What exit reasons are default? 3. How could DMA interrupt the cpu when it finishes and the qemu-kvm is still running in kvm now? I am still working in the patch, but these confusions really prevent me moving forward. Thanks first for you guys giving me more hints. The following is the code so far I write: The main idea is synchronizing the CPU state and enter into the emulator mode when switching from kvm to emulator. I only do the switch when the exit reason is KVM_EXIT_IRQ_WINDOW_OPEN. However, I got the following errors: Whenever switch from kvm to qemu, the interrupt request in qemu will cause qemu enter into smm mode which is definitely a bug. This is the code that tries to synchronize the CPU state when the IRQ Window is open. And then tries to switch back to the QEMU emulator mode. --- qemu-0.12.3/kvm-all.c 2010-02-23 12:54:38.000000000 -0800 +++ de-0.12.3/kvm-all.c 2010-04-01 12:23:07.000000000 -0700 @@ -577,7 +577,6 @@ { struct kvm_run *run = env->kvm_run; int ret; - dprintf("kvm_cpu_exec()\n"); do { @@ -641,7 +640,8 @@ dprintf("kvm_exit_unknown\n"); break; case KVM_EXIT_FAIL_ENTRY: - dprintf("kvm_exit_fail_entry\n"); + printf("kvm_exit_fail_entry\n"); + exit(1); break; case KVM_EXIT_EXCEPTION: dprintf("kvm_exit_exception\n"); @@ -670,7 +670,31 @@ env->exit_request = 0; env->exception_index = EXCP_INTERRUPT; } - + + /* de, start emulation */ + if(env->ask_for_emulation){ + //if( (env->eflags & IF_MASK) && (run->ready_for_interrupt_injection)){ + if(run->exit_reason == KVM_EXIT_IRQ_WINDOW_OPEN ){ + int saved_vm_running = vm_running; + vm_stop(0); + if (kvm_arch_get_registers(env)) { + printf("Fatal: kvm vcpu get registers failed\n"); + abort(); + } + env->kvm_state->regs_modified = 1; + env->is_in_emulation = 1; + target_ulong pc_start = env->segs[R_CS].base + env->eip; + /* int flags = env->hflags |(env->eflags & (IOPL_MASK | TF_MASK | RF_MASK | VM_MASK)); */ + /* int code32 = !((flags >> HF_CS32_SHIFT) & 1); */ + printf("start emulation at pc: 0x%x, eip:0x%x\n", pc_start, env->eip); + /* target_disas(stderr, pc_start, 10, code32); */ + /* env->interrupt_request = 0; */ + printf("tr type:%d\n", (env->tr.flags >> DESC_TYPE_SHIFT) & 0xf); + + if(saved_vm_running) + vm_start(); + } + } return ret; } ask_for_emulation is in the CPU_COMMON --- qemu-0.12.3/cpu-defs.h 2010-02-23 12:54:38.000000000 -0800 +++ de-0.12.3/cpu-defs.h 2010-03-28 15:17:14.000000000 -0700 @@ -197,6 +197,8 @@ const char *cpu_model_str; \ struct KVMState *kvm_state; \ struct kvm_run *kvm_run; \ - int kvm_fd; + int kvm_fd; \ + int ask_for_emulation; /* ask for emulation if 1 */ \ + int is_in_emulation; /* is in emulation */ when is_in_emulation, don't enter kvm again in cpu_exec --- qemu-0.12.3/cpu-exec.c 2010-02-23 12:54:38.000000000 -0800 +++ de-0.12.3/cpu-exec.c 2010-03-30 00:38:01.000000000 -0700 #if defined(TARGET_I386) - if (!kvm_enabled()) { - /* put eflags in CPU temporary format */ - CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); - DF = 1 - (2 * ((env->eflags >> 10) & 1)); - CC_OP = CC_OP_EFLAGS; - env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); - } + if (!kvm_enabled() || env->is_in_emulation) { + /* put eflags in CPU temporary format */ + CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); + DF = 1 - (2 * ((env->eflags >> 10) & 1)); + CC_OP = CC_OP_EFLAGS; + env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); + } - if (kvm_enabled()) { - kvm_cpu_exec(env); - longjmp(env->jmp_env, 1); - } + if (kvm_enabled() && !env->is_in_emulation) { + kvm_cpu_exec(env); + longjmp(env->jmp_env, 1); + } command "start_emulation", "stop_emulation" support in the monitor --- qemu-0.12.3/monitor.c 2010-02-23 12:54:38.000000000 -0800 +++ de-0.12.3/monitor.c 2010-03-28 15:16:18.000000000 -0700 @@ -56,6 +56,9 @@ #include "json-streamer.h" #include "json-parser.h" #include "osdep.h" +/* de */ +static void do_start_emulation(Monitor *mon, const QDict *qdict, QObject **ret_data) +{ + CPUState *env = mon_get_cpu(); + env->ask_for_emulation = 1; + monitor_printf(mon, "Starting emulation...\n"); +} + +static void do_stop_emulation(Monitor *mon, const QDict *qdict, QObject **ret_data) +{ + CPUState *env = mon_get_cpu(); + env->ask_for_emulation = 0; + monitor_printf(mon, "Stop emulation\n"); +} + +static void do_is_emulation(Monitor *mon, const QDict *qdict, QObject **ret_data) +{ + CPUState *env = mon_get_cpu(); + if(env->is_in_emulation) + monitor_printf(mon, "Emulating now\n"); + else + monitor_printf(mon, "Virtualizing now\n"); +} + Thanks for the help, guys. I appreciate for your time to help! regards, Wenhao On Thu, Apr 1, 2010 at 1:42 AM, Avi Kivity <avi@redhat.com> wrote: > On 03/31/2010 02:31 PM, Juan Quintela wrote: >> >> Wenhao Xu<xuwenhao2008@gmail.com> wrote: >> >>> >>> Hi, Juan, >>> I am fresh to both QEMU and KVM. But so far, I notice that QEMU >>> uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can >>> use and uses cpu_register_physical_memory_offset to register the same >>> memory to QEMU emulator, which means QEMU and KVM use the same host >>> virtual memory. And therefore the memory KVM modified could be >>> directly reflected to QEMU. I don't quite understand the different >>> memory layout problem between the two. So I don't know exactly what >>> you mean to "fix" it? >>> >> >> 1st. qemu-kvm.git and qemu.git memory layouts are different, indeed with >> qemu.git kvm mode. (yes it is complex and weird). >> >> kvm vs qemu initialization is different. Expecting to stop kvm, and run >> tcg from there is not going to work. I guess it would need a lot of >> changes, but I haven't looked at it myself. >> > > I don't think it's so far fetched. In fact early versions of qemu-kvm > switched between emulation and virtualization (emulate until 64-bit mode, > also emulate mmio instructions in qemu). > > Even today, all memory initialization is done via generic qemu mechanisms. > So long as you synchronize all state (pit, irqchip, registers) you should > be fine. > >>> For why switching is useful? Actually, I am a master student now >>> and doing a course project. What am I arguing is that QEMU could be >>> potentially useful to do many instrumentation analysis, but it is a >>> bit slow. So by combing with KVM, when the os runs to some place where >>> we are interested in, switch it to QEMU emulator mode and do the >>> analysis and then switch back. >>> >> >> idea is good, but I don't think that it is _so_ easy at this point. tcg >> and kvm basically live in a different world. Not sure of what needs to >> be done to make them back on sync. >> > > cpu_synchronize_state() > > -- > error compiling committee.c: too many arguments to function > > -- ~_~ ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [questions] savevm|loadvm 2010-04-01 19:35 ` [Qemu-devel] " Wenhao Xu @ 2010-04-07 5:56 ` Avi Kivity -1 siblings, 0 replies; 17+ messages in thread From: Avi Kivity @ 2010-04-07 5:56 UTC (permalink / raw) To: Wenhao Xu; +Cc: Juan Quintela, qemu-devel, kvm, aliguori, paul On 04/01/2010 10:35 PM, Wenhao Xu wrote: > Does current qemu-kvm (qemu v0.12.3) use the irqchip, pit of KVM? I > cannot find any KVM_CREATE_IRQCHIP and KVM_CREATE_PIT in the qemu > code. > > Are you looking at qemu or qemu-kvm? > Concerning the interface between qemu and kvm, I have the following confusion: > 1. How irqchip and pit of KVM collaborating with the irq and pit > emulation of QEMU? As far as I see, qemu-kvm still uses qemu's irq and > pit emulation, doesn't it? > No, they're completely separate. > 2. For return from KVM to QEMU, I cannot get the meaning of two exit reasons: > case KVM_EXIT_EXCEPTION: > What exception will cause KVM exit? > I think that's obsolete. > default: > dprintf("kvm_arch_handle_exit\n"); > ret = kvm_arch_handle_exit(env, run); > What exit reasons are default? > > 3. How could DMA interrupt the cpu when it finishes and the qemu-kvm > is still running in kvm now? > Usually the device that does the dma will raise an interrupt, which qemu is waiting for. > I am still working in the patch, but these confusions really prevent > me moving forward. Thanks first for you guys giving me more hints. > > > The following is the code so far I write: > The main idea is synchronizing the CPU state and enter into the > emulator mode when switching from kvm to emulator. I only do the > switch when the exit reason is KVM_EXIT_IRQ_WINDOW_OPEN. > That doesn't happen with qemu-kvm. > However, I got the following errors: > Whenever switch from kvm to qemu, the interrupt request in qemu will > cause qemu enter into smm mode which is definitely a bug. > Definitely shouldn't happen. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ^ permalink raw reply [flat|nested] 17+ messages in thread
* [Qemu-devel] Re: [questions] savevm|loadvm @ 2010-04-07 5:56 ` Avi Kivity 0 siblings, 0 replies; 17+ messages in thread From: Avi Kivity @ 2010-04-07 5:56 UTC (permalink / raw) To: Wenhao Xu; +Cc: aliguori, paul, qemu-devel, kvm, Juan Quintela On 04/01/2010 10:35 PM, Wenhao Xu wrote: > Does current qemu-kvm (qemu v0.12.3) use the irqchip, pit of KVM? I > cannot find any KVM_CREATE_IRQCHIP and KVM_CREATE_PIT in the qemu > code. > > Are you looking at qemu or qemu-kvm? > Concerning the interface between qemu and kvm, I have the following confusion: > 1. How irqchip and pit of KVM collaborating with the irq and pit > emulation of QEMU? As far as I see, qemu-kvm still uses qemu's irq and > pit emulation, doesn't it? > No, they're completely separate. > 2. For return from KVM to QEMU, I cannot get the meaning of two exit reasons: > case KVM_EXIT_EXCEPTION: > What exception will cause KVM exit? > I think that's obsolete. > default: > dprintf("kvm_arch_handle_exit\n"); > ret = kvm_arch_handle_exit(env, run); > What exit reasons are default? > > 3. How could DMA interrupt the cpu when it finishes and the qemu-kvm > is still running in kvm now? > Usually the device that does the dma will raise an interrupt, which qemu is waiting for. > I am still working in the patch, but these confusions really prevent > me moving forward. Thanks first for you guys giving me more hints. > > > The following is the code so far I write: > The main idea is synchronizing the CPU state and enter into the > emulator mode when switching from kvm to emulator. I only do the > switch when the exit reason is KVM_EXIT_IRQ_WINDOW_OPEN. > That doesn't happen with qemu-kvm. > However, I got the following errors: > Whenever switch from kvm to qemu, the interrupt request in qemu will > cause qemu enter into smm mode which is definitely a bug. > Definitely shouldn't happen. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [Qemu-devel] Re: [questions] savevm|loadvm 2010-03-31 11:31 ` [Qemu-devel] " Juan Quintela @ 2010-04-01 12:20 ` Paul Brook -1 siblings, 0 replies; 17+ messages in thread From: Paul Brook @ 2010-04-01 12:20 UTC (permalink / raw) To: qemu-devel; +Cc: Juan Quintela, Wenhao Xu, kvm > Wenhao Xu <xuwenhao2008@gmail.com> wrote: > > Hi, Juan, > > I am fresh to both QEMU and KVM. But so far, I notice that QEMU > > uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can > > use and uses cpu_register_physical_memory_offset to register the same > > memory to QEMU emulator, which means QEMU and KVM use the same host > > virtual memory. And therefore the memory KVM modified could be > > directly reflected to QEMU. I don't quite understand the different > > memory layout problem between the two. So I don't know exactly what > > you mean to "fix" it? > > 1st. qemu-kvm.git and qemu.git memory layouts are different, indeed with > qemu.git kvm mode. (yes it is complex and weird). > > kvm vs qemu initialization is different. Expecting to stop kvm, and run > tcg from there is not going to work. I guess it would need a lot of > changes, but I haven't looked at it myself. FWIW I think this really *should* work, and any failure to do so is definitely a bug. Paul ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: [Qemu-devel] Re: [questions] savevm|loadvm @ 2010-04-01 12:20 ` Paul Brook 0 siblings, 0 replies; 17+ messages in thread From: Paul Brook @ 2010-04-01 12:20 UTC (permalink / raw) To: qemu-devel; +Cc: Wenhao Xu, kvm, Juan Quintela > Wenhao Xu <xuwenhao2008@gmail.com> wrote: > > Hi, Juan, > > I am fresh to both QEMU and KVM. But so far, I notice that QEMU > > uses "KVM_SET_USER_MEMORY_REGION" to set memory region that KVM can > > use and uses cpu_register_physical_memory_offset to register the same > > memory to QEMU emulator, which means QEMU and KVM use the same host > > virtual memory. And therefore the memory KVM modified could be > > directly reflected to QEMU. I don't quite understand the different > > memory layout problem between the two. So I don't know exactly what > > you mean to "fix" it? > > 1st. qemu-kvm.git and qemu.git memory layouts are different, indeed with > qemu.git kvm mode. (yes it is complex and weird). > > kvm vs qemu initialization is different. Expecting to stop kvm, and run > tcg from there is not going to work. I guess it would need a lot of > changes, but I haven't looked at it myself. FWIW I think this really *should* work, and any failure to do so is definitely a bug. Paul ^ permalink raw reply [flat|nested] 17+ messages in thread
* [questions] savevm|loadvm @ 2010-03-30 6:03 Wenhao Xu 0 siblings, 0 replies; 17+ messages in thread From: Wenhao Xu @ 2010-03-30 6:03 UTC (permalink / raw) To: kvm Hi, all, I am working with switching QEMU from running in KVM mode to QEMU emulatoin mode dynamically. Intuitively, if the snapshot created using savevm in kvm mode can be used by the loadvm command in QEMU emulator mode, the switchment could makes use of this. I tried to do so. However, it does not work. Any idea how to fix it? Thanks for the help. regards, Wenhao -- ~_~ ^ permalink raw reply [flat|nested] 17+ messages in thread
end of thread, other threads:[~2010-04-07 5:56 UTC | newest] Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2010-03-30 5:59 [questions] savevm|loadvm Wenhao Xu 2010-03-30 5:59 ` [Qemu-devel] " Wenhao Xu 2010-03-30 8:22 ` Juan Quintela 2010-03-30 8:22 ` [Qemu-devel] " Juan Quintela 2010-03-30 17:03 ` Wenhao Xu 2010-03-30 17:03 ` [Qemu-devel] " Wenhao Xu 2010-03-31 11:31 ` Juan Quintela 2010-03-31 11:31 ` [Qemu-devel] " Juan Quintela 2010-04-01 8:42 ` Avi Kivity 2010-04-01 8:42 ` [Qemu-devel] " Avi Kivity 2010-04-01 19:35 ` Wenhao Xu 2010-04-01 19:35 ` [Qemu-devel] " Wenhao Xu 2010-04-07 5:56 ` Avi Kivity 2010-04-07 5:56 ` [Qemu-devel] " Avi Kivity 2010-04-01 12:20 ` Paul Brook 2010-04-01 12:20 ` Paul Brook 2010-03-30 6:03 Wenhao Xu
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