| Message ID | 4EA99BC8.9040402@codemonkey.ws |
|---|---|
| State | New |
| Headers | show |
On Thu, 27 Oct 2011 12:58:32 -0500, Anthony Liguori <anthony@codemonkey.ws> wrote: > On 10/27/2011 03:20 AM, Kevin Wolf wrote: > > Am 26.10.2011 22:49, schrieb Anthony Liguori: > >> On 10/25/2011 10:22 AM, Kevin Wolf wrote: > >>> Am 25.10.2011 17:03, schrieb Eduardo Habkost: > >>> I think qemu-iotests could be considered an instance of B) > >>> > >>>> C) Functional tests that just need to run a small binary with no OS > >>>> installed in the guest, but running a fully-feature qemu process. > >>>> - The tests in the 'tests' directory do this, right? kvm-unittests > >>>> does this, right? > >>> > >>> Not sure what test/ does, but for kvm-unittests yes. And this is also > >>> what I was talking about. > >> > >> Thinking more about this... > >> > >> We could add a new '-x-test-server CHR' option. When this option is added, it > >> would do the following: > >> > >> 1) Open CHR character device > >> 2) Use /dev/shm for guest memory > >> 3) Listen for connections on CHR > >> 4) When something connects to CHR > >> a) reset device model > >> b) send /dev/shm fd over CHR > >> c) register CPU physical memory client > >> 1. upon CPU physical memory changes, send the change info over CHR > >> d) instead of doing [kvm_]cpu_exec(), block reading on CHR > >> > >> So when you launch qemu with -x-test-server, it'll sit there doing nothing > >> terribly useful. But this lets you write a program that connects to CHR, and > >> then by mapping {out,in}[bwl] to RPCs over the connection, and accessing RAM via > >> mmap()'ing the passed fd using the client mapping table, you can essentially > >> write kvm-unittest style tests while still having full access to libc. > > > > IRQs need to go through the connection as well. > > Yes, forgot to mention that. > > > > > Oh, and you would finally have a C user for libqmp. The test cases > > definitely need to be able to access the monitor. For example I would > > really love to have test cases for the I/O error paths that stop the VM > > (or actually it's the resume that must be tested). > > Yeah, tunnelling a monitor session sounds like a really good idea. > > >> And since each test program can reset QEMU after running, you could very nicely > >> tie into something like gtest as a unit test framework. I think it's pretty > >> appealing from a debugability perspective too. > >> > >> It also means that it's possible to have 100% C test cases such that you could > >> still build something like ppc64-softmmu and run it against the written test > >> cases without having to really understand ppc64 assembly or have a ppc64 build > >> environment (to generate native binaries to run under ppc64 TCG). > >> > >> I think this could work out fairly well as a unit test framework. > > > > Sounds great, where are the patches? ;-) > > Heh, need to find a volunteer although I spent a few minutes this afternoon > trying to figure out how hard it would be. Turns out, it's much simpler than I > expected if you do the same trick that Xen does. Instead of mucking with > hooking cpu_exec, Xen simply starts the CPUs in the halted state such that TCG > simply never runs. The following patch is all we really need. > > test_init() just needs to register the appropriate file descriptor callbacks and > then in the data path dispatch PIO/MMIO. It would also need to override > cpu_interrupt_handler to intercept interrupt operations. > > diff --git a/hw/pc.c b/hw/pc.c > index eb4c2d8..f3fd32d 100644 > --- a/hw/pc.c > +++ b/hw/pc.c > @@ -923,12 +923,18 @@ void pc_acpi_smi_interrupt(void *opaque, int irq, int level) > } > } > > +extern int test_allowed; > + > static void pc_cpu_reset(void *opaque) > { > CPUState *env = opaque; > > cpu_reset(env); > - env->halted = !cpu_is_bsp(env); > + if (test_allowed) { > + env->halted = 1; > + } else { > + env->halted = !cpu_is_bsp(env); > + } > } > > static CPUState *pc_new_cpu(const char *cpu_model) > diff --git a/vl.c b/vl.c > index 1ddb17b..adc626a 100644 > --- a/vl.c > +++ b/vl.c > @@ -1988,6 +1988,19 @@ static int tcg_init(void) > return 0; > } > > +static int test_init(void) > +{ > + printf("Hello World\n"); > + return 0; > +} > + > +static int test_available(void) > +{ > + return 1; > +} > + > +int test_allowed = 1; > + > static struct { > const char *opt_name; > const char *name; > @@ -1998,6 +2011,7 @@ static struct { > { "tcg", "tcg", tcg_available, tcg_init, &tcg_allowed }, > { "xen", "Xen", xen_available, xen_init, &xen_allowed }, > { "kvm", "KVM", kvm_available, kvm_init, &kvm_allowed }, > + { "test", "Test", test_available, test_init, &test_allowed }, > }; > > static int configure_accelerator(void) > vl.c seems to have changed a bit since then, but I think this was the same basic approach we took with QTest: http://repo.or.cz/w/qemu/mdroth.git/commitdiff/2e55d8a892297512f6c7883aff2c4b082bd6a3d5?hp=07d8a50cb0e096c5cdc5a81b8030e40833664dd3 http://wiki.qemu.org/Features/QTest There was even a brief period where we were using gtest, but GLib hadn't been merged yet so we pulled it "temporarially" before going off and working on other stuff. > > > Kevin > > > >
diff --git a/hw/pc.c b/hw/pc.c index eb4c2d8..f3fd32d 100644 --- a/hw/pc.c +++ b/hw/pc.c @@ -923,12 +923,18 @@ void pc_acpi_smi_interrupt(void *opaque, int irq, int level) } } +extern int test_allowed; + static void pc_cpu_reset(void *opaque) { CPUState *env = opaque; cpu_reset(env); - env->halted = !cpu_is_bsp(env); + if (test_allowed) { + env->halted = 1; + } else { + env->halted = !cpu_is_bsp(env); + } } static CPUState *pc_new_cpu(const char *cpu_model) diff --git a/vl.c b/vl.c index 1ddb17b..adc626a 100644 --- a/vl.c +++ b/vl.c @@ -1988,6 +1988,19 @@ static int tcg_init(void) return 0; } +static int test_init(void) +{ + printf("Hello World\n"); + return 0; +} + +static int test_available(void) +{ + return 1; +} + +int test_allowed = 1; + static struct { const char *opt_name; const char *name; @@ -1998,6 +2011,7 @@ static struct { { "tcg", "tcg", tcg_available, tcg_init, &tcg_allowed }, { "xen", "Xen", xen_available, xen_init, &xen_allowed }, { "kvm", "KVM", kvm_available, kvm_init, &kvm_allowed }, + { "test", "Test", test_available, test_init, &test_allowed }, }; static int configure_accelerator(void)